Of Disease in general.—The nature of the Plague as a
Disease considered.—Of Contagion.—Whether the Plague
is really Contagious or not.—Medical History of the Distemper.—Inquiry
into its Immediate Causes, and whether
an approaching Plague is indicated by any visible Signs.
HITHERTO we have considered the origin of the
plague entirely in a moral point of view. We
have seen, that, in conformity to the general opinion of
mankind, it may reasonably be supposed to have been
inflicted upon mankind, the Jews particularly, for their
transgressions; that, having been once introduced, it
has been perpetuated, and spread from nation to nation,
and that in proportion to the degree of immorality of
a certain kind prevailing through the world. From
this it is naturally to be inferred, that, were the human
race to live at peace with one another, to disperse themselves
over the face of the earth for the purpose of
improving it by cultivation, and were they to be contented
with what the produce of each country affords,
there would be no plague among them. But we know
that such a reformation is not to be expected, and we
must take the world as we find it. The question then
is, By what means shall individuals secure themselves
from being destroyed by a plague which shall happen to
invade any country; or how shall a person, already
infected with it, be restored to health? For this purpose
let us begin with considering the nature of disease in
general, and of the plague particularly.
As to disease in general, physicians have differed very
considerably in their definitions; and, though many
have been given, few seem to be unexceptionable. That
of Dr. Fordyce seems to be among the clearest and
most expressive. “Disease (says he) is such an alteration
in the chemical properties of the fluids or
solids, or of their organization, or of the action of
the moving powers, as produces an inability or difficulty
of performing the functions of the whole or any
part of the system, or pain, or preternatural evacuation.”
But as this definition, however just, cannot
be easily understood by such as are unaccustomed to
medical language, I shall attempt the following explanation
of the animal economy, and the diseases to
which it is subject.
1. By nature our bodies are formed of certain solid
and fluid parts, operating upon one another in a manner
of which we know but little. Anatomists have described
the structure of the human body and its parts in
a certain degree, but have always found themselves
lost in an inconceivable minuteness of texture. The
whole structure of the human body, visible and invisible,
is called its ORGANIZATION.
2. This organized body is acted upon by certain
powers residing in the atmosphere, by which it becomes
endowed with LIFE.
3. The operation of those powers upon a well organized
body constitutes that agreeable and vigorous state
which we call HEALTH.
4. The operation of any other power, substituted in
place of the natural one, even upon a body perfectly
organized, produces a state very different from health;
commonly attended with some uneasy sensations, and
which is called DISEASE. I say it is commonly attended
with uneasiness, but not always; for many persons
within a few hours, nay, a few minutes, of their death,
have imagined themselves quite recovered and well.
To illustrate the meaning of what is said of the substitution
of any power instead of the natural one: It is
natural for man to breathe air of a certain quality; and
while he does so he continues in health; but let him
breathe the vapour of burning charcoal, or of fermenting
liquor, mixed in considerable quantity with the air to
which he has been accustomed, and he will very soon
find himself diseased. Many other kinds of elastic
fluids may be substituted instead of the vapour just
mentioned, all of which will in a short time produce a
disease in the most healthy man. The state of a diseased
body being very different from that of a sound
one, the appearances are consequently very different.
The various appearances of disease in the human body
are called symptoms of that disease, from a Greek word
signifying appearance.44
5. A disease proves mortal only by the DISORGANIZATION
of the body. By disorganization I mean any
considerable alteration in the structure of the body, visible
or invisible. The truth of this will appear from
a consideration of the method by which animals may be
recovered, after being to appearance dead by breathing
the vapour of charcoal, or fixed air in any other form,
viz. by plunging them in cold water. In a cave in
Italy a continual stream of this kind of air issues from
the ground. It rises but a small way, so that a man
may safely enter, because his head is above the vapour;
but, if he brings a small dog with him, the animal, in
consequence of breathing the pernicious fluid, falls down
as if dead, and would very soon die if left there. By
throwing it into a lake in the neighbourhood, (cold
water of any kind would answer as well) it recovers. In
the dissection of some unfortunate people, who have
been killed by breathing this pernicious fume, a manifest
disorganization has been observed, viz. a rarefaction
of the blood, and too great dilation, or even rupture, of
the small vessels.
6. A disease cannot always be cured by removing the
cause which brought it on: it is necessary also to repair
the injury done to the organization. This is exemplified
in the case of the dog just mentioned. Taking
him out of the vapour is not sufficient for his recovery,
because the organization of the body is injured; the
cold water by contracting the vessels repairs the injury,
and the cure is completed. To the entire preservation
of this organization it is probably owing, that people
have frequently recovered after being thought dead for
a long time.45
7. When the organization of the body is injured, the
action of the natural powers themselves occasions uneasiness,
and increases the disease. The cure then is, to
substitute instead of the natural power, as far as possible,
the action of some other power till the organization
is restored; after which the natural power must be
again allowed to act, or a disease of another kind will
take place. This may be exemplified in a consumption
of the lungs; where, that part being very much disorganized,
pure air renders the disease worse; and the
sick are relieved by mixing with the common atmosphere
such kinds of air or vapour as would prove pernicious
to people in health. But, supposing this method
to be successful, and the consumption to be entirely
removed, it is plain that the use of the pure atmosphere
must be resumed, or the impure air would bring on a
disease in the same manner as on a healthy person.
8. The body is wasted in the natural operations of
life; part of it passing off with the vapour of the breath,
part by insensible perspiration, &c. Hence it naturally
tends to disorganization and death, unless the waste be
repaired.
9. This natural waste of the body is repaired, and
health kept up, by the food and drink taken into the
stomach.
10. Hence arises another set of diseases; for as the
reparation of the waste, just mentioned, depends on the
proper action of the stomach upon the food, and the
assimilation of the latter with the substance of the body,
it is plain that this operation depends both on the
proper quality of the food, and the sound state of the
stomach itself.
11. The body is composed of solids and fluids of different
kinds, every one of which is subject to diseases
peculiar to itself; but, by reason of the connexion of
the parts of the body with one another, it is impossible
that any one can be very much disordered without affecting
all the rest. As the bond of connexion, however,
is in many cases totally invisible to us, surprising
instances frequently occur of one part being affected in
consequence of an injury done to another very distant
from it. This connexion between all parts of the
body is called SYMPATHY. Dr. Gardiner of Edinburgh,
in his observations on the animal economy, &c.
says, that “the stomach is the principal seat of many of
the most remarkable sympathetic affections which
happen in valetudinary states of the body. Every
disorder accompanied with severe pain affects the stomach,
whilst this viscus affects not only in its diseased
state every part of the system, but at other
times the effects of healthful stimuli applied to it are
instantly communicated to the rest of the body, as
when we take food, wine, or medicine.” Dr. Darwin
in his Zoonomia informs us that the stomach is said to
sympathize with almost every part of the body; but Dr.
Moore, in his medical sketches, tells us that the heart
possesses a greater share of sympathy than any other part
in the body, and next to it the stomach.46
12. The solid parts of the body are the bones, the
muscles, brain and nerves; the fluids are, the blood,
and others produced from it. The bones are known to
every one; the muscles are the fleshy parts throughout
the whole body; and the nerves are a kind of cords
seemingly originating from the brain, and from thence
accompanying the blood vessels through all parts of
the body.
13. Much has been disputed about what is to be
accounted the primary part of the body, on which all
the rest depend; and one class of disputants have arranged
themselves on the side of the blood, and the other
on that of the nerves. The dispute is like one about
the beginning of a circle. It cannot be decided, because
the blood cannot act without nerves, nor the
nerves without blood. I speak of the human body,
being aware that in some animals the position may be
controverted. The following is a concise state of the
matter.
14. All the blood in the body passes through the
heart; which has four cavities; two called ventricles,
and two auricles. These, from their position in the body,
are called the right and left. The right ventricle communicates
with the right auricle, as does also the left
ventricle with the left auricle; but there is no communication
between the right ventricle and the left, nor
between the right auricle and the left. Through these
cavities all the blood passes to every part of the body,
and returns from every part; but, as in the former case,
we are here at a great loss where to begin its motion;
for this is precisely to find the beginning of a circle.
As we must begin somewhere, however, we shall do so
with the right ventricle of the heart. This receives the
blood returning from all parts of the body, and propels
it into the right ventricle; not the whole quantity at
once, for it cannot contain one half of it; but by degrees.
The auricle contracts as soon as it is full; and
in the time that the auricle fills, the ventricle contracts,
so that it may be empty, and ready to receive the blood
from the auricle. By the contraction of the right ventricle
the blood is driven into the pulmonary artery, and
passes into the lungs. Here the artery branches into an
infinite number of small vessels much finer than hairs;
and these again, uniting into larger trunks, form at last
the pulmonary vein, which brings back the blood to
the heart. The pulmonary vein is inserted into the
left auricle of the heart, which, as soon as it is filled with
blood, contracts, and expels the blood from it into the
left ventricle. From the left ventricle issues a large
artery called the aorta, which by its branches supplies
the whole body with the vital fluid. In all parts of the
body the arteries divide themselves into innumerable
small branches, which terminate in veins equally small
as in the lungs; but it has been disputed whether the
arteries and veins actually join each other in the form of
vessels, or whether the arteries deposit the blood in small
cells, from which the veins suck it up. The dispute is
of no consequence, nor can it be absolutely decided, on
account of the exceeding smallness of the vessels;
though the microscopical observations are rather favourable
to the opinion of a continuation of vessels. The
veins from all parts of the body unite into larger vessels,
and these again uniting with one another, form at last
one very large vein called the vena cava, which opens
into the right auricle of the heart, from which the circulation
goes on as already described. The two ventricles
of the heart, and all the veins throughout the body,
are furnished with a kind of valves, which allow the
blood to proceed in the way of circulation, but prevent
its returning in a contrary direction.
15. The lungs, through which all the blood in the
body passes, receive likewise the air which we draw in
every time we breathe. They consist of two large bodies
called lobes; from their situation called the right
and left. The air is conveyed into them by the wind-pipe,
called also the trachea, and the aspera arteria. On
entering the cavity of the breast, the wind-pipe divides
into two large branches called the bronchiæ; one of
which goes to the right and the other to the left lobe of
the lungs. By the further division and subdivision of
these vessels the lungs are filled with an innumerable
multitude of little tubes, terminating in exceedingly
minute bladders or cells, which are the final receptacles
of the air sucked in when we breathe. Each of these
cells is surrounded with a kind of network of blood-vessels
exceedingly small, and consisting of very thin membranes;
so that, in passing through the lungs, the blood
is exposed as much as possible to the action of the air.
16. It is a matter of great importance to find out
what is the use of this exposure of the blood; and
great disputes have taken place concerning it. In former
times it was supposed that the blood received from
the air a vital spirit, without which it would have been
totally incapable of performing its offices in the body.
Later physiologists endeavoured to explode this notion.
Dr. Hales particularly, by shewing that the circulation
of the blood through the lungs might be continued by
inflating and contracting them alternately by the fumes
of burning brimstone, endeavoured to prove that the use
of the air was only to give the lungs an opportunity of
dilating and contracting alternately, by which means
principally he thought the circulation might be carried
on. This continued to be the most common hypothesis
as late as the time of Dr. Huxham. It was however
thought also that by the compression of the air the
blood was altered in its texture, its bulk, &c. Accordingly
Dr. Huxham tells us in the preface to his treatise
on air and epidemic diseases, that “air fit for respiration
ought neither to be too hot, nor very cold; for the
use of the inspired air is to temperate the blood, which
would otherwise grow too hot, and putrefy, as is evident
from the experiment of the most excellent Boerhaave
made in a hot house; for, if the air is more hot,
or even equally hot, as the blood of any animal, it certainly
soon dies.”47
17. The modern discoveries in the composition of air,
have tended greatly to elucidate the use of this fluid in
the lungs, and its action on the blood in respiration.
Dr. Priestly first determined it to be what he terms a
phlogistic process, i. e. a process by which the parts of the
blood no longer proper to be retained among the rest, or
at least some of them, are carried off. That something is
carried off either from the lungs themselves, or from the
blood circulating through them, is evident; for the air
which is taken into the lungs in a dry state, comes out
of them extremely moist, and loaded with vapour. An
essential change is also made in the nature of the air itself;
for it now assumes in a great measure the nature
of what has been called fixed air, or the fume of charcoal,
or fermenting liquor, and thus becomes unfit for
being breathed a second time. This change is made by
the addition of some terrestrial substance to the pure
atmosphere, which the latter volatilizes and carries along
with it.48
18. But, whatever may be carried off from the blood,
during its passage through the lungs, something is certainly
added to it, for the blood in the pulmonary artery
is of a dark red, but when it has undergone the action
of the air in the lungs, and returns by the pulmonary
vein, it is then of a bright scarlet, which colour it retains
through all the arteries of the body, but loses it on its
return through the veins. This scarlet colour is communicated
to blood in all cases when exposed to the
air; and Dr. Priestley has observed that it is acted upon
by the air even through a bladder; much more then
must it be so through those very thin membranes which
form the coats of the fine pulmonary vessels. What
this subtile matter is which the blood receives, shall be
afterwards inquired into; at present it is sufficient to
take notice that it is absolutely necessary, for the purposes
of life, that the blood should pass through the
lungs: for, as Dr. Huxham observes, “we see neither
nutrition, nor the motion of the muscles, performed
by any blood that hath not passed through the lungs;
this is observable from the coronary arteries49 to the
ultimate ramifications of the aorta.” As the previous
circulation of the blood through the lungs therefore is
absolutely necessary to the growth and life of the body,
and as the blood certainly receives something from the
air, we must account this a proof, and no inconsiderable
one, that the air contains a vital spirit, which it imparts
to the blood in the lungs. But, before we proceed farther
on this subject, it is proper to take some notice of
19. The nerves. These, which constitute such a remarkable
and important part of the human body, are
white cords, of a soft pulpy substance, defended by a
tough skin which goes along with them as far as they
can be traced. All the nerves either originate from the
brain, or terminate in it. The former doctrine hath
been generally adopted, and in conformity to that doctrine
the following account of the nerves is laid down.
The brain is enclosed in the cavity of the scull, but not
without the intervention of two membranes, called the
dura and pia mater, to prevent injury from the hard
bones, as well as for other purposes. The brain is divided
into two lobes, the right and left. It is composed of
two different kinds of substance, the outermost called
the cortical, the innermost the medullary substance; the
latter seems composed of fine fibres. The whole of the
medullary part of the brain terminates in a substance
called the cerebellum, very much resembling the brain,
but smaller. The cerebellum terminates in another
substance resembling the medullary part of the brain,
called the medulla oblongata. The cerebellum lies in the
back part of the head, and the medulla oblongata under
it. The latter terminates in the spinal marrow, extending
from the lower and back part of the head to the
lower extremity of the back bone, and is enclosed in the
hollow of that bone. The nerves proceed from these
four substances, viz. the brain, the cerebellum, the medulla
oblongata, and spinal marrow. As they pass to all
parts of the body they accompany the arteries, dividing
with them into innumerable small branches; but they
do not return with the veins; so that they seem not to
contain any fluid which goes and comes, or which circulates
like the blood. The nervous fluid, if any such
there be, seems to move constantly one way, either to
the brain or from it.
20. Hitherto we have noticed only things which are
evident to our senses, and which the industry of anatomists
has abundantly evinced; but now our subject renders
it necessary to step aside a little into the obscure
regions of theory and conjecture. The muscles, as we
have formerly said, are the fleshy parts of the body; and
by them all the motions of the body are performed.
The flesh is distributed into distinct portions, each of
which is enclosed in a membrane belonging to itself.
Each of these portions is a muscle, and each muscle has
a branch of an artery and the branch of a nerve belonging
to it. On both these the action of the muscle depends;
for, if we cut the nerve belonging to a muscle,
it immediately loses all power of action; and if we cut
the artery which accompanies the nerve, it does the
same. As therefore the blood is found to receive something
from the air, and as it loses this when passing
through the arteries, and as the nerves lose their power
when the communication with the blood is cut off, it
seems extremely probable, that what is imbibed by the
blood in the lungs is taken up by the fine ramifications
of the nerves, and is no other than the immediate principle
of life and sensation. Thus we will establish a
doctrine directly opposite to that commonly received;
for, instead of supposing that the nerves originate from
the brain, we are now led to suppose that they terminate
in it. Instead of supposing that the sensations originate
in the brain, we will be led to suppose that every sensation
originates in the organ appointed for that sensation.
Thus we are conscious that our eyes, not our brain, are
the parts of our body which immediately perceive the
light; our fingers, or any other parts of the body, feel
what is applied to them; and of consequence we have
reason to believe that the animal spirits, nervous fluid, or
whatever we please to call it, proceed from the surface
of the body inwards to the brain, not outwards from the
brain to the surface of the body. The brain itself seems
to resemble a large collection or reservoir of water, in
which the sensations, like so many small streams from
every part of the body, unite, and in which our intellectual
faculties reside in a manner totally inexplicable by
us. Thus far it seemed necessary to theorise, in order
to form some idea, however obscured, of the connexion
between the nerves and our sensitive and intellectual, or,
if we please to call them so, our spiritual faculties.
21. In consequence of this very intimate connexion
between the blood and nerves, it is easy to see that any
injury done to the one may very greatly affect the other;
and that a very slight, nay, to us imperceptible, change
in the organization of either, may produce the most
grievous, and even incurable disorders throughout the
whole body, or in any particular organ. Let us now
consider a little farther the blood-vessels.
22. It hath been a question, whether in the structure
of these vessels nature hath observed an exact proportion.
For instance, if the blood passes by a kind of starts
through four cavities, as we are assured that it does, it
seems natural to suppose that these four should be exactly
equal. This, however, hath been denied; and
some, from its accommodating the human frame to
their theory, have fancied that they saw the use of such
disproportionate work. Dr. Huxham expresses himself
in the following words: “Nor doth the air only refrigerate
the blood, but, by preventing its too great ebullition,
and condensing it, hinders it from bursting the
vessels. This indeed is of exceeding great importance,
if, with the very learned Helvetius, we suppose the capacity
of the right ventricle of the heart to be greater
than that of the left, and that the pulmonary arteries
are larger than the correspondent veins; for it thence
follows, that the blood ought to be considerably condensed
by the inspired air, that an equal quantity of
blood may be received, in one and the same time, by
the pulmonary veins and left ventricle of the heart,
that is thrown off from the right ventricle, and
through the more capacious pulmonary arteries. This
indeed many deny, asserting quite the contrary. It is
necessary, however, that the aorta should receive as
much blood from the left ventricle of the heart, as is
thrown off from the right ventricle through the pulmonary
artery; and that in the very same and equal
time, or a fatal deluge would soon overwhelm the
lungs, because the contraction of each ventricle is
made at one and the same time; we always find
therefore the aorta and pulmonary artery, in a natural
state, equal on this account; also the capacity of the
ventricles ought to be equal, that they may receive,
in one and the same space of time, equal quantities of
blood,” &c.
If any thing farther is necessary upon this subject, we
may still observe, that if the blood were at all condensed
by the air, it would be so unequally, because the air is
at some times much colder than at others; and thus the
disproportion of the cavities of the heart to one another
could not fail of producing the most disagreeable if not
fatal effects. We often see what terrible consequences
ensue upon the enlargement of any part of an artery
near the heart; and these would, sometimes at least, be
felt by every individual.50
It is true, indeed, that this objection will in some degree
hold, even though we suppose all the cavities of the
heart to be equal, and the capacities of the blood vessels
to be perfectly uniform throughout the whole body.
For, if we suppose the blood to be at all condensed in
the lungs by the coldness of the atmosphere, it must undoubtedly
follow, that while passing from them it occupies
less space than before it arrives at them. Hence
the pulmonary vein, the left auricle of the heart, the left
ventricle, the aorta, and all the rest of the arteries for a
considerable way, must be comparatively empty, even
though they receive as much fluid as fills the vena cava,
right auricle and ventricle of the heart, and pulmonary
artery. The equality which ought to prevail in
the system, and which indeed cannot be dispensed with,
can only take place in those remoter branches of the arteries
in which the blood has reassumed its former state
of dilation or rarefaction.
23. If we consider this matter attentively, we shall
find it not a little mysterious. Every time we breathe
out the air we have sucked into our lungs, a considerable
quantity of moist vapour is breathed out along with it;
but it has been proved by undeniable experiments that
the emission of aqueous vapour from any substance cools
it in proportion to the quantity of vapour emitted.
Every breath we draw, then, cools the lungs, and
consequently the blood, to a certain degree, and, as the
number of times that we breathe in a day is exceedingly
great, the cold produced by the evaporation ought to be
in proportion. But we see that, notwithstanding all this
cooling, whether we breathe cold air or hot air, the
temperature of the body remains still the same. The
air then, though constantly carrying off the heat of the
body, does not cool it in the least by its action on the
lungs. The only possible way of solving this apparent
contradiction is, by supposing that the air, when acting
upon the blood in the lungs, leaves precisely as much
heat as it carries off, and therefore, though we breathe
ever so long, we cannot by this means become either
hotter or colder.
24. To illustrate this subject, we might now enter
into an inquiry concerning the origin and cause of
animal heat; but this will be touched upon hereafter.
We shall here only take notice that the heat of the body
is almost universally allowed to proceed from the lungs.
It has likewise been demonstrated, that the air does in
fact contain an incredible quantity of heat, even when it
appears to us to be extremely cold. A certain proportion
of this heat is separated from it every time we
breathe; and if, either by the mixture of other fluids
with the air we breathe, or by any change in the organization
of the body itself, a greater or smaller proportion
of heat should be communicated to the blood, disease
must ensue.
25. To sum up then what has been said concerning
the blood and nerves: The whole mass of fluid passes
from the right side of the heart to the lungs. In the
lungs it receives from the air something52 necessary to
the functions of life and sensation, and purifies itself from
those matters which might prove pernicious. From
the lungs it passes to the left side of the heart, and
thence through the whole body. In its passage through
the body, it is accompanied with nerves, which, taking
up from the arterial blood that vital spirit received from
the air, convey it to all the organs of motion, of sensation,
and to the brain, where the whole powers of
perception being united form our intellectual faculties,
and, as far as our senses can perceive, the human spirit
itself. The blood, thus deprived of its spirit, is collected
from all parts of the body by the veins, and returned
to the right side of the heart, from whence it is again
sent to the lungs, and the process carried on as before.
This hypothesis concerning the peculiar function of the
nerves I first inserted in the Encyclopædia Britannica,
second edition, under the article Blood, in the year
1778. It has been since continued in the third Scots
edition, and from thence into the Irish and American
editions.
26. It has already been observed, that the body is
subjected to a continual waste. One source of this
waste is the breath, by which a considerable part passes
off in vapour. A great quantity also passes off by the
pores of the skin; frequently in a perceptible liquid
called sweat, but oftener in an invisible vapour from all
parts of the body, called insensible perspiration. The latter
has been thought to be the great source of waste to
the human body; and it is certain, that if any person in
health be weighed when he rises in the morning, he will
be found considerably lighter than when he went to bed.
The loss of weight in this case proceeds not only from
the pores of the skin, but from the lungs; but though
physicians have made a general allowance for both these,
I have not heard of any experiment by which we can
determine how much passes off by the one, and how
much by the other, nor indeed does it appear easy to
make such an experiment. Galen plainly overlooks the
perspiration from the lungs entirely. “This excrementitious
vapour (says he) is expelled through small orifices,
which the Greeks call pores, dispersed all over
the body, and especially over the skin, partly by sweat,
and partly by insensible perspiration, which escapes
the sight, and is known to few.” Sanctorius, and the
succeeding writers, have classed both together indiscriminately;
allowing the discharge to be so great, that if
eight pounds of aliment be taken in, five of them pass
off in this manner. In a system of anatomy, published
at Edinburgh in 1791, the author says, that the discharge
by the skin “is even much larger than this (the
discharge from the lungs we may suppose) since it
not only throws off a quantity of the aliment, but
likewise what is added to the blood by inhalation,
which, entering often in a very considerable quantity,
is thus again expelled.” The same author likewise
says, that the “perspirable matter from the skin is principally
water,” and that it issues in such quantity as to
be seen in subterraneous caverns evidently flying off
from the surface of the body like a dense vapour. But
other physiologists, particularly Dr. Blumenbach, inform
us, that the matter of insensible perspiration is quite
similar to the discharge from the lungs, particularly containing
a great quantity of fixed air. The same account
is given in Chaptal’s chemistry, on the authority
of Messrs. Milly and Fouquet. This may be looked upon
as a valuable discovery, especially in conjunction with
that related by Drs. Beddoes and Girtanner, viz. that
the flesh of animals contains a quantity of oxygen. Dr.
Girtanner obtained a quantity of this air from the raw
flesh of animals, and says that it may be repeatedly obtained
by exposing the flesh to the atmosphere, and
distilling with a heat of 60 or 70 degrees of Reaumur’s
thermometer (something below that of boiling water.)
Hence it is natural to conclude, that, as the discharge
from the lungs purifies the blood from its useless parts,
so does the insensible discharge from the skin purify the
solid parts from those particles which are no longer useful.
The probability of this also becomes greater by
considering, that in diseases, when the quantity of matter
to be thrown off is very great, the skin becomes foul,
the teeth furred with black sordes, &c. all which disappear
as soon as the quantity of the offensive particles is
reduced to its natural standard. As to any considerable
quantity of aqueous vapour being discharged this way,
unless in case of sweat, it does not seem probable; for
in such a case our clothes would always be moist; and
in the night time the accumulation of moisture would
certainly be perceptible. The sweat is entirely of a different
nature from the insensible perspiration, and blood
and even sand has been known to issue through the skin
along with it. (See the Anatomical System above quoted.)
27. This very considerable waste of the body is repaired
by the aliment taken into the stomach. In the
mouth it is mixed with a considerable quantity of
the liquid called saliva, and in the stomach with another
called the gastric juice, with which that organ always
abounds. From the stomach it passes into the intestines,
where it is mixed with other two fluids; one called
the pancreatic juice, the other the bile. This last is of a
yellow colour, and is sometimes produced in enormous
quantities, insomuch that Dr. Wade, in his account
of the fevers in Bengal, mentions some patients who
have voided by stool half a gallon of bilious matter
in one day.
28. In the stomach principally the aliment undergoes
a certain change called digestion, by which it becomes
capable of being converted into the substance of the
body. Much has been inquired and disputed, to no
purpose, about the nature of this change, and how it is
effected. One party has declared for attrition; a second
for putrefaction; a third for heat; a fourth have supposed
that our meat was digested by chewing; as if, like the
lobster, people had teeth in their stomach! and, lastly,
some learned moderns, after much pains and trouble,
have found out that it is digested by solution. Dr.
Moore has summed up the discoveries concerning digestion
in the following words: “The food, being previously
divided and blended with the saliva and air by mastication,
(chewing) is swallowed, and meets in the stomach
with the gastric juice, whose dissolving power,
assisted by the natural heat of the place, is the principal
agent in digestion. The process is completed by
the pancreatic juice and bile, the nutritious parts of
the food being by this process converted into chyle
for the support of the body, and the grosser parts
thrown out.”53
29. The inside of the stomach and intestines are full
of the mouths of innumerable small vessels, which continually
suck up from the aliment, as it passes downwards,
the finer parts, in form of a white liquid, called chyle;
and from the whiteness of their colour the vessels have
the name of lacteals, from the Latin word lac, milk.
After passing through the substance of the stomach and
intestines, and running along the membrane called the
mesentery, to which the intestines are attached, the lacteals
unite in a large reservoir called the thoracic duct;
and this again opens into a large vein on the left side,
called the subclavian, which conveys the blood from half
the upper part of the body; soon after terminating in
the vena cava, by which the chyle is conveyed to the
heart, thence to the lungs, and so on in the common
course of circulation. The conversion of the chyle into
blood is called the process of sanguification.
30. The blood, thus formed out of the aliment we
swallow, is not one uniform fluid like water, but composed
of three distinct substances; one, which gives it
the red colour, and seems to be composed of little round
globules; another, quite colourless, but of a viscid nature,
and which very soon coagulates, called the lymph;
and a third, of a yellowish colour, and retaining its fluidity
much longer, called the serum. A remarkable
property of this last fluid is, that air can act through it
upon the blood; for Dr. Priestly found that a portion
of black blood assumed a bright, florid colour from the
air, even though covered with serum an inch deep.
When blood is drawn, the red globules are detained by
the lymph which coagulates, and both together form
the red mass called crassamentum; the serum remaining
fluid, and retaining its name.
31. Besides these fluids, the blood either invisibly
contains, or is capable of being converted into, a great
many others; for all the fluids in the body are separated
from it, and all of them, the bile only excepted, from
the arterial blood, before it has lost that portion of its
spirit which it imbibes from the air. When a fluid is
to be secreted, sometimes it is done only by an infinity
of small vessels branching off from the arteries, and depositing
the liquids which pass through them in particular
places; and such are the fluids which moisten the
inside of the body, and which are carried off by the
breath, or by sweat. But this separation does not by
any means hinder the artery from terminating in its usual
way in a vein, for in no case is the whole substance of
the blood converted into any other liquid; all of them
appear to be contained in it. But the greatest number
of fluids are separated by means of certain substances
called glands. These are small round or oval shaped
bodies; each of them enclosed in a membrane or skin
which separates it from the other parts, and each furnished
with a small tube called the excretory duct, through
which the liquor separated in the gland passes to its
place of destination. Each gland has also an artery and
nerve, and a vein to bring back the blood after it has
parted with the fluid intended to be separated. The
bile is separated in the liver from the blood of a large
vein called the vena portarum, formed by the union of
some of the veins of the intestines and mesentery. This
vein branches out through the liver like an artery, terminating
in other veins, which at last bring back the blood
to the heart.
32. As the human body is thus furnished with an
apparatus for separating and carrying off, it is also furnished
with one for absorbing or taking in. All the
inward parts of the body are moist; and the moisture is
furnished by the small vessels above described, and
which separate part of the lymph from the blood. By
such continual separation the cavities of the belly,
breast, brain, &c. would soon be filled with liquid, were
not some means provided for carrying it off as fast as it
is formed. The means in question are a set of small
vessels called lymphatics. These “arise from the internal
surface of the breast, belly, and every cavity of the
body; they also overspread the whole external surface
of the body, and large lymphatic vessels are usually
found close to the large blood vessels of the extremities,
besides those small superficial ones which lie
above the muscles in the cellular membrane (the fat
or rather the membrane containing it.) The large
viscera generally have two sets of lymphatics, one
lying on the surface of the viscus, and the other
accompanying the blood vessels belonging to it. The
faculty of absorption, though refused to the lymphatics,
was ascribed by many anatomists to common veins,
and this opinion continued to prevail in some degree,
until Hunter and Monro totally overturned it,
exploding at the same time the notion that any of the
lymphatics are continuations of arteries, and establishing,
beyond a doubt, that all are absorbent vessels.”54
All the lymphatics terminate in the thoracic duct; so
that the liquid separated by the exhalant arteries (so the
vessels are termed by which that fluid is separated) is
again mixed with the blood, and again performs the
same offices.
We have now taken a review of the several parts of
the human body, slight and superficial indeed, but such
as the limits of this work would allow, and sufficient to
furnish to those entirely unacquainted with medical
matters some general ideas on the subject. We have
seen that the body, in general, consists principally of
four great parts, the blood-vessels, the lymphatic vessels,
the nerves, and the muscles. Besides these we enumerate
the glands and membranes; the former being nearly
allied to the blood-vessels, the latter apparently to the nerves.
The bones, having no concern with our present inquiry, are
not taken notice of. The stomach and intestines, being
principally composed of muscular fibres, nerves, and
blood-vessels, must be considered as belonging to these
departments. Each of these large divisions has obtained
the name of system; and even the subdivision of the
blood-vessels into arteries and veins. Thus the arteries
of the body, taken collectively, are called the arterial system;
the veins the venous system; the brain and nerves the
nervous system; the muscles the muscular system; the lymphatics
the lymphatic system; and the glands the glandular system;
&c. These appellations have been given for the sake of distinctness
and perspicuity, but they have had a bad tendency.
Insignificant disputes have arisen concerning the
superiority of one system to the other, and which is to be
accounted the primum mobile of the body. By observing
also the general structure of the body in a more full and
ample manner than that of the parts which compose it,
physicians have been apt to generalize too much in their
theories, and to fancy that from a few obvious laws they
might be able to explain the phenomena of disease in
almost every possible variety. To illustrate this, let us
take the blood for an example. This to sight appears
an homogeneous fluid; and Boerhaave and others have
ascribed diseases to some defect or bad quality of the
blood. But this fluid consists of three parts, each, as far
as we can perceive, essentially distinct from the other;
viz. the lymph, serum, and red globules. As each of
these happens to be diseased, the cure must be different;
or if two happen to be diseased, the medicines must still
be varied. But, besides these general diseases arising
from what, like the blood, is common to the whole
body, each component part of the body has an arterial
system, a venous system, a nervous and lymphatic
system, &c. belonging to itself; all of which, though
dependent on the body at large, have yet laws of their
own, in consequence of which any one of them may be
considerably diseased without much affecting the general
system; and this constitutes what is called local disease.
Again: The parts of the body are so connected with
one another, that the disease of one may show itself in
another; or it may affect the whole body in such a
manner as to produce a general disease; though Dr.
Rush considers this last, at least from injuries of the
viscera, as a rare occurrence;55 but we certainly know
that general diseases are very often followed by evident
diseases of particular organs; and in these cases it is impossible
to say whether the general disease did not begin,
though imperceptible to us, in that very organ in which
we suppose it to terminate when the local disease was
come to such an height as to be evident to our senses.
In some cases it is plain that local injuries will bring on
most violent diseases of the whole system. Thus a local
inflammation of the end of one of the fingers, by physicians
called a paronychia, has been known to induce a
most violent fever, nay, even to occasion death. These
violent symptoms end as soon as the suppuration is
completed; so that, were it not for the excessive pain of
the inflammation, we might be apt to suppose that the
fever terminated in the suppuration, whereas it evidently
was occasioned by the local disease, or the tendency
of the part to suppurate; the pain and inflammation
being necessary preliminaries. Again: When
an intermittent fever is said to terminate, or to be followed,
by a hardness of the liver, we do not certainly
know whether an original disease of the liver might not
have been the cause of the intermittent. From a consideration
of all these things, viz. the extreme diversity
of parts which compose the human body, the ultimate
invisibility of the structure of each, the incomprehensible
manner in which they are united, the equally incomprehensible
dependence they have upon one another in some
cases, and independence in others, the numerous laws by
which they are governed, and which must be very much
unknown to us, the invisible and incomprehensible nature
of the powers which act upon them, &c. &c. I say,
when we consider all these things, the boldest theorist
must be humbled when he attempts to account for the
phenomena of disease in any one instance. The excessive
difficulty in which we are involved is beautifully
described by Dr. Ferriar when speaking of hysterics;
and obstacles equally insuperable by our theories will
undoubtedly be met with in any other distemper.
“We are ignorant (says he) by what laws the body possesses
a power of representing the most hazardous disorders,
without incurring danger; of counterfeiting
the greatest derangement in the circulating system,
without materially altering its movements; of producing
madness, conscious of its extravagances; and of
increasing the acuteness of sensation by oppressing the
common sensorium. In hysterical affections all these
appearances are excited, which are incompatible with
the reasonings of every system-maker who has yet endeavoured
to explain the inexplicable. Nature, as if
in ridicule of the attempts to unmask her, has, in this
class of diseases, reconciled contradictions, and realized
improbabilities, with a mysterious versatility, which
inspires the true philosopher with diffidence, and reduces
the systematic to despair.”
Notwithstanding all these difficulties, however, physicians
have theorised, and that with such animosity, as
if all the arcana of nature had been laid open to every
professor who thought proper to invent or new-model a
system; though the constant succession of theories
might certainly have shown them the vanity of such
attempts. Some of these we must now consider.
Medical theorists have exerted their greatest abilities
in explaining the nature of those general diseases affecting
the whole body, denominated fevers; and which
are likewise called acute diseases, from the violence with
which they sometimes attack, and the rapidity with
which they run through their course. Dr. Fordyce
says, that fever will sometimes kill in five minutes from
the first sensation of uneasiness. Ancient physicians
have described a number of fevers, which they supposed
to be of different species, and accordingly have distinguished
by different names. Modern system-makers
have added to the number; so that a bare detail of
the names which they have given to their divisions and
subdivisions, would constitute a very formidable catalogue;
but the latest practitioners are decidedly of
opinion that there is but one kind of fever, varying itself
according to circumstances. Dr. Rush declares
himself of this opinion in the most express and positive
terms. “There is (says he) but one fever. However
different the predisposing, remote or exciting causes
may be, . . . still, I repeat, there can be but one
fever. . . . Thus fire is an unit, whether it be produced
by friction, percussion, electricity, fermentation,
or by a piece of wood or coal in a state of inflammation.”56
“I have said that there is but one fever. Of course
I do not admit of its artificial division into genera
and species; a disease which so frequently changes
its form and place, should never have been designated,
like plants and animals, by unchangeable characters. . . .
Much mischief has been done by nosological
arrangements of diseases. They erect imaginary
boundaries between things which are of an homogeneous
nature. . . . They gratify indolence in a
physician, by fixing his attention upon the name of a
disease, and thereby leading him to neglect the varying
state of the system, &c.”57
So much then having been said and written upon the
disease in question, one might be apt to suppose that the
nature of fever would have been thoroughly investigated,
and its causes explained in the most satisfactory manner,
long before this time. Instead of this, however, we find
it still like a word which every body uses, and nobody
understands. Dr. Fordyce, who has lately written a
treatise on the subject, endeavours to prove that there
is not any single symptom from the existence of which
we can certainly determine the presence of this disease.
“Fever (says he) has obtained its name in Greek, Latin,
Arabic and Persian, principally from the idea of heat:
pur, in Greek fire; febris in Latin, from fervere, to
burn,” &c. This idea, he goes on to demonstrate, is
erroneous; as the body of a feverish patient frequently
sinks the thermometer below the natural standard; while
the patient sometimes finds himself cold when the thermometer
shows him to be really hot, and hot while the
same instrument shows him to be cold. Neither is cold,
followed by heat, a certain indication of the presence of
fever, as many fevers begin without any previous sensation
of cold. Frequency of the pulse also is no certain
sign; and having discussed this last symptom he concludes
thus. “If we examine the restlessness, anxiety,
state of the tongue, head-ach, or any other of the
symptoms which often take place in fever, we shall
find that they also may be present when there is no
fever, and absent in a patient afflicted with this disease;
and therefore we cannot allow that there is any pathognomic
symptom of fever.”58 Dr. Rush declines giving
any definition of fever;59 but, with all due deference to
these two very experienced physicians, we must account
such extreme scepticism altogether erroneous. If fever
cannot be defined, it cannot be described; for a definition
is no other than a short description. If again there
be no single symptom by which the presence of fever can
be known, it is impossible that there can be any combination
by which it can be known, any more than we
can form an unit by any combination of cyphers. In
fact Dr. Fordyce himself is at last obliged to acknowledge
that there is a certain symptom with which fever generally
begins; and, by his insisting upon it in various parts of
the work, we must certainly be induced to suppose that
it was by this sign principally that he determined whether
his patients had a fever or not. “The first appearance
(says he) which generally takes place is uneasiness
and restlessness; a general uneasiness, the patient feeling
himself ill, but incapable of fixing on any particular
part of the body. This uneasiness affects the mind
at the same time. Perhaps in this case it is the mind
that is first affected. . . . Along with this uneasiness
there is a restlessness, the patient wishing to change
his place or posture frequently; the mind cannot likewise
rest upon one object; it often wanders from one
to another subject. At the same time there is a feel
of weariness which resists the disposition in the patient
to change his place and posture, and resists the disposition
of the mind to alter the object of its attention,
rendering the wish for such changes ineffectual.
With these arises an actual inability of exerting the
muscular powers, or performing any of the functions
of the body; and also an actual inability of exercising
the great faculties of the mind, the powers of perception,
memory, arrangement of ideas, and of the judgment,
in the same degree that they existed in health.
The degree in which these take place is extremely
different in the attacks of different fevers; but these
appearances are very rarely absent, although indeed
they may also happen in other diseases.”
Dr. Rush accounts the lassitude with which fever
begins, one of the transient phenomena of it; and this
with other phenomena he calls symptoms. Such as are
more permanent and fixed, and which by other writers
have been reckoned different species, he calls states;
and of these he enumerates forty. Such as have any
relation to the plague are as follow.
I. The MALIGNANT state, known by attacking frequently
without a chilly fit, is attended with coma, a
depressed, slow or intermitting pulse, and sometimes by
a natural temperature or coldness of the skin. . . .
This depressed state of fever more frequently when left
to itself terminates in petechiæ, buboes, carbuncles,
abscesses and mortifications, according as the serum,
lymph, or red blood, is effused in the viscera or external
parts of the body.
2. The SYNOCHA, or common inflammatory state;
attacking suddenly with chills, succeeded by a quick,
frequent and tense pulse, great heat, thirst, and pains in
the bones, joints, breast or sides.
3. The BILIOUS state of fever; known by a full, quick
and tense pulse, or by a quick, full and round pulse
without tension, and by a discharge of green, dark coloured
or black bile from the stomach and bowels.
This state sometimes assumes the form of an hectic;
the patient feels no pain in his head, has a tolerable appetite,
and is even able to sit up and do business.
4. The TYPHUS state; known by a weak and frequent
pulse, a disposition to sleep, a torpor of the alimentary
canal, tremors of the hands, a dry tongue, and, in some
instances, a diarrhœa. Sometimes it assumes symptoms
of synocha on the eleventh, fourteenth, and even twentieth
days. The common name of this state is the
nervous fever.
5. Intermissions, or the INTERMITTING and REMITTING
states, occur most distinctly and universally in
those which partake of the bilious diathesis.
6. The SWEATING state occurs not only in the
plague, but in the yellow fever, small pox, pleurisy,
rheumatism, hectic and intermitting states.
7. The FAINTING state; occurring in the plague, yellow
fever, small pox, and some states of pleurisy.
8. The BURNING state. This is attended not only
with an intolerable sensation of heat in the bowels, but
with a burning sensation excited in those who touch the
patient’s skin. It occurs mostly in the remitting fevers
of Asia.
9. The CHILLY state differs from a common chilly
fit by continuing four or five days, and to such a degree
that the patient frequently cannot bear his arms out of
bed. The coldness is most obstinate in the hands and
feet. A coolness only of the skin attends in some cases,
which is frequently mistaken for an absence of fever.
10. The INTESTINAL state; including the cholera
morbus, diarrhœa, and cholic.
11, 12, 13, 14, 15. The APOPLECTIC, PHRENETIC,
PARALYTIC, LETHARGIC and VERTIGINOUS states.
16. The ERUPTIVE state; including the small pox,
measles, and other exanthemata of Dr. Cullen.
17. The HÆMORRHAGIC state; known by fluxes of
blood from various parts of the body.
18. The CONVULSIVE or SPASMODIC state. Convulsions
are frequently attendant on the malignant state
of fever.
19. The CUTANEOUS state; attended with various
eruptions on the skin, particularly petechiæ.
These include the most remarkable varieties described
by physicians as different species. From the subsequent
account of the symptoms of the plague, it will appear
that this single distemper monopolises, as it were, the
symptoms, at least the most dangerous and terrible, belonging
to them all. Those nosologists therefore who
suppose the states of fever above described to be different
species, instead of saying that the plague belongs to one
kind of fever, ought to say that it is a complication of a
great many different kinds. But here a question arises:
Do all the varieties of fever just now described, or do all
the other fevers described by different authors, include
all the different modes by which the plague makes its
attack? If so, then we know that the plague really
partakes of the nature of fever, or may be accounted
the highest degree of it. This is the opinion of Dr.
Rush; for in his 4th vol. p. 153, he considers the
different inflammatory states of fever, according to their
strength, in the following order. 1. The plague. 2.
The yellow fever. 3. The natural small pox. 4. The
malignant sore throat, &c. To this I can have but
one objection, and to me it appears insuperable; viz.
that the plague frequently destroys without any symptom
of fever; and, if so, we must certainly account
it a distemper of another kind. To decide this
matter, let us compare the symptoms of the most violent
fever with what happens in times of violent pestilence.
We can scarce imagine a fever more powerful
than that which destroys in five minutes, and the following
is the description of it from Dr. Fordyce. “When
the first attack of fever has been fatal, it has been
classed among sudden deaths, and all of these have
been very erroneously called apoplexy, or syncopy
(fainting.). . . . When the attack is fatal, it sometimes
kills in five minutes, sometimes it requires half an
hour, seldom longer than that time. While the patient
is yet sensible, violent head-ach with a great sense
of a chilliness takes place, the extremities become very
cold, and perfectly insensible; there is great prostration
of strength, so that the patient is incapable of supporting
himself in an erect posture; he becomes pale, his
skin is of a dirty brown, and he is soon insensible to
external objects; the eyes are half-open, and the cornea
somewhat contracted. If the patient goes off very
soon, the pulse is diminished, and at last lost, without
any frequency taking place, but if it be longer before
he dies, the pulse becomes excessively small and frequent;
all the appearances of life gradually subside,
and the patient is carried off. Of this the author has
seen instances, sometimes at the first attack, oftener in
the returns of the disease, although very few.”
This no doubt is very terrible, and no plague whatever
can exceed it. Indeed, when death is the termination,
it signifies little what the disease is called. But the
question is not whether fever or plague is the most dreadful,
but whether they are the same. Now, from the
above description, it is plain that fever never kills without
some warning. In the present instance, head-ach
and chilliness give a certain, though short, warning of
the ensuing catastrophe; but, in violent plagues, Dr.
Sydenham informs us, that people have been suddenly
destroyed as if by lightning. Dr. Guthrie assures us
that in the last plague at Moscow he has seen soldiers
drop down suddenly as if they had been struck by lightning,
or by a musket ball; yet some of these recovered
by bleeding and proper management; but it is certainly
not unreasonable to suppose that many, who were not
thus taken care of, perished. Dr. Hodges speaks of the
contagion of the plague in the most energetic terms. He
says, “it is so rare, subtile, volatile and fine, that it insinuates
into, and resides in, the very pores and interstices
of the aerial particles. It is said to be of a
poisonous nature also, from its similitude to the nature
of a poison, so that they seem to differ in degree only;
for the deadly quality of a pestilence vastly exceeds
either the arsenical minerals, the most poisonous animals
or insects, or the killing vegetables; nay, the
pestilence seems to be a composition of all the other
poisons together, as well as in its fatal efficacies to excel
them. . . . The contagion of the plague is
more active than lightning, and in the twinkling of an
eye carries to a distance putrefaction, mortification
and death. As for the manner whereby it kills, its
approaches are generally so secret, that persons seized
with it seem to be fallen into an ambuscade or a
snare, of which there seems to be no suspicion. . . .
In the plague of 1665, as in many others, people frequently
died without any symptoms of horror, thirst,
or concomitant fever. A woman, who was the only
one left alive of a family, and in her own opinion in perfect
health, perceived upon her breast the pestilential
spots, which she looked upon to be the fatal tokens;
and in a very short space died, without feeling any
other disorder, or forerunner of death. . . . A youth
of a good constitution, after he had found himself suddenly
marked with the tokens, believed at first that
they were not the genuine marks, because he found
himself so well; yet he was dead in less than four
hours, as his physician had prognosticated. A fever,
however, did for the most part show itself, and was
always of the worst kind. Sometimes it seemed to resemble
a quoridian, sometimes a tertian; there never
was a total cessation, but every exacerbation was worse
than before.” In like manner the author of the
Journal of the Plague Year informs us that many, supposing
themselves, and supposed by others, to be in good
health, would suddenly find themselves seized with great
sickness, crawl to a bench, and instantly expire. “Many
(says Dr. Hodges) in the middle of their employ,
with their friends and other engagements, would suddenly
fall into profound, and often deadly sleeps.”
It is needless to multiply examples: the above are
sufficient to show that the plague, when in its most violent
state, kills suddenly and imperceptibly, and that
like the bite of a vampire,60 without producing any sensible
disorder. In a state somewhat inferior, it excites
the most malignant fevers; in one still inferior it produces
fevers of a milder nature, and so on until we find
it so mild, that those infected with it are not even confined
to their bed. In all this inquiry, however, we find
the secrecy and invisibility of the pestilence, so often
mentioned in scripture, still confirmed. Other distempers
may “waste openly at noon-day,” but this always
“walks in darkness.”
In one of the inferior stages of this distemper the body
is affected with those eruptions named buboes and carbuncles.
Dr. Patrick Russel, in his treatise on the
plague at Aleppo, divides the symptoms of the distemper
into six classes. In the first there were no eruptions,
and all the patients of this class died. In the second,
and all the rest, there were buboes and carbuncles. But,
in the latter of these especially, it is worthy of remark,
that they appear neither as a suppuration, nor as a common
mortification, but like the eschar formed by a caustic,
which can scarcely be cut by a knife. This appearance
is not to be met with in any other disease. In
many there are mortifications of various parts of the
body, but all these are soft, and seemingly corruptions
of the flesh. When a person dies of any ordinary distemper,
the flesh soon corrupts and dissolves, but there
is no example of its turning to a hard eschar like that
made by a hot iron, or the caustic with which issues are
made. This shews not merely a cessation of life, but
the operation of some very active power in the body,
like fire, tending to destroy the texture of it entirely, and
to reduce it to a cinder. This power seems also to
operate internally in the fleshy parts; for when the
bodies of those were opened who died with the tokens,
as they are called by Dr. Hodges, upon them, the mortification
was always found much larger inwardly than
it appeared to be on the outside. The tokens themselves
are by Dr. Hodges called “minute distinct biasts,
which had their origin from within, and rose up in
little pyramidal protuberances, sometimes as small as
pins’ heads, at others as large as a silver penny; having
the pestilential poison chiefly collected at their
bases,” &c.
That the plague was by the ancients reckoned a
disease of a nature different from all others, appears from
Galen, as quoted by Deusingius. “What is called the
pestilence is most properly remarked by Galen not to
be a genus of any known disease. For whatever diseases
and symptoms are associated with the plague,
truly and properly so called, the same are wont to be
called pestilential diseases; of which indeed there are
an innumerable multitude, and these not always nor
every where the same.”61
In like manner Diemerbroeck, as quoted by Allen,
gives his opinion, that “The plague is something different
from a fever, and a fever is only a symptom of
it, as I have very often observed; and therefore some
very ill define the plague by a fever, since a fever does
not essentially belong to it. . . . A pestilential fever,
the companion of the plague, is not occasioned by a
pestilential venom, but by the mediation of putrefaction;
that is, it is not produced because the humours
are infected with the pestilent venom, but because
the heart, being irritated, overwhelmed and
much weakened by the pestilent venom, can neither
duly digest and rarefy, nor govern and sufficiently discharge
the infected humours; which for this reason
putrefy and acquire a preternatural heat, and so excite
a fever; which by reason of the foresaid secondary
cause, is different and distinct from the plague, and a
symptom of it. This is confirmed both by the maxims
and authority of the ancients and moderns, as
well as by practice, and evident examples.”
Thus it appears, both by fair reasoning by induction
from facts, and from the authority of the greatest physicians,
that the plague is certainly a disease by itself,
and entirely distinct from all others. Hence it follows,
that, though we could investigate the causes of fever in
their utmost extent, we might still be ignorant of the
true plague. That nothing, however, may be omitted,
let us now consider what physicians have advanced on
this subject, and what progress they have made in ascertaining
the sources from whence so many direful calamities
are derived.
In an inquiry of this kind, or indeed concerning any
cause whatever, it is plain that the nature of the effect
must be first understood. Fever then being an effect,
we must begin with investigating its nature. But fever
itself is only manifest by certain changes in the human
body. Before we can investigate the nature of fever,
therefore, we must investigate the human body, and
that in a manner very different from what we did before.
We must now consider the sources of life; in what
manner the vital principle acts upon the body, and by
what means its motions can be disturbed, or how they
may be rectified when once disordered, &c. &c.
The systems of medicine before the time of Boerhaave
are now so generally exploded, that it is needless to take
any notice of them; and the reputation of Boerhaave
himself in this way seems to be almost expiring. His
doctrines, nevertheless, merit some attention, because he
takes into account a principle overlooked by succeeding
theorists, viz. the cohesion of the parts of the body. That
he did so is evident, from his having written upon the
diseases of a weak and lax fibre, and the diseases of a
strong and rigid fibre. In other respects he followed in a
great measure the mechanical physicians of the former
century. He therefore took but little notice of the
nervous system, as being less subject, or indeed to appearance
not at all subject, to the known laws of mechanics.
The blood was more manageable. The
microscopical discoveries of Lewenhoeck furnished an
excellent foundation for his system. This celebrated
observer had discovered, or fancied he had discovered,
that the red part of the blood is composed of globules.
Inaccurate indeed these globules must have been, since
each of them was composed of six; four touching one
another in the middle, with one above, and one below,
thus 
. The serum was said to be composed of single
globules, and by this attenuation it was supposed that the
fluid, instead of red, appeared of a yellow colour. Still,
however, this was insufficient. Each of the yellow globules
was discovered (either by fancied observations or
by conjecture, it matters not which) to be composed of
six others, which, singly taken, might constitute the
lymph or some other fluid; and thus, like the number
of the Beast, we might go on by sixes to the end of the
chapter, and solve all the phenomena of nature. In
justice to the microscopists, however, it must be observed,
that some of them have given a much less fanciful
account of the structure of the blood than Lewenhoeck.
Mr. Hewson found it composed of vesicles, or small
bladder-like substances, with a black spot in the middle.
These vesicles dissolved in pure water, but kept their
original form, which he says was as flat as a shilling,
when a small portion of neutral salt was added to the
fluid. The solid particles he supposed to be produced
by the lymphatic system; the black particles by the
spleen.
The supposed observations of Lewenhoeck were of
considerable use to Boerhaave in the forming of his
system of medicine, though they seem not to have
accorded very well with his doctrine of lentor or viscidity
in the blood. But, let this be as it will, having laid it
down as the foundation of his theory, that the diseases
of the body proceeded from too great a laxity of the
fibres, or from too great a rigidity of them, and a great
many from this lentor, his practice was accordingly directed
to such medicines as he imagined would remove
these supposed causes of disease. As the lentor of the
blood was one of his favourite suppositions, he was therefore
perpetually at war with this imaginary enemy, and
dealt very much in saponaceous medicines with a view
to break it down. But here it is evident that this great
man was mistaken, even though we should allow the
existence of lentor as much as he pleased. The viscidity,
lentor, or any other state of the blood, is an effect of
something. It is part of that state into which the body
is brought by the disease. The efforts of the physician
therefore ought to be against that which produces the
lentor; for, unless this be done, the cause of the disease
must perpetually counteract the medicines by producing
new lentor as fast as they destroy it; and besides, must
have greatly the advantage of the physician, by being
already in possession of the whole mass of blood, while
the medicines can only enter it very gradually, and that
by the stomach and lacteals, instead of being instantly
mixed with it, and exerting their power immediately
upon the fluid itself.
But besides this mistake, which is common to other
systems, Boerhaave’s lentor has been denied, and that
upon such strong grounds that it is now universally exploded.
Another system quickly succeeded, in which
every thing was managed by the nerves. This was
introduced by Hoffman, adopted, and perhaps improved,
by Dr. Cullen, under whose auspices it acquired such
a degree of celebrity, that for a long time it was dangerous
to write or speak against it; and the person who had
the audacity to do so underwent a kind of medical
proscription from the Edinburgh College and all its
students. According to this celebrated theorist, the
brain is that part of the body first formed in the
embryo; it may be seen with nerves proceeding; from it
long before the heart or any blood-vessel belonging to it
is visible. Hence we are to conclude that this part
is necessary to the existence of every other part of the
body, though it doth not appear that they are essentially
necessary to its existence. The superiority of the nerves
to all other parts being thus established, the Doctor
undertook to prove that all other parts of the body
were formed from them; that the body is nourished
immediately from them, and in short that the whole
body is in such subjection to the nervous system, that,
except for the mere purpose of distending the vessels, we
can scarcely know for what end the blood exists;
since the nerves can alter its consistence, or that of any
of the fluids secreted from it, by a mere affection of that
system, without any thing either added to or taken from
the vital fluid.
Thus we were compelled to believe that all diseases
at their first origin are affections of the nervous system,
from whence they are propagated through the whole
body. The Cullenian practice in acute diseases, of which
the plague is the most violent, was built upon a maxim
of Hoffman: “Atonia gigoit spasmos:” Atony produces
spasms. In explaining the nature of typhus fever, therefore,
with which he classes the plague, the Doctor supposed
that the contagion acted first upon the nervous
system, by producing therein a debility. The immediate
effect of this debility is a spasm, or preternatural contraction
of the capillary vessels, or extremely small arteries.
Hence the blood finds some difficulty in circulating,
and the patient is seized with shivering, and has
a sense of cold. When this has continued for some
time the system begins to re-act against its enemy; the
spasm is resolved, and, the reaction of the system continuing,
the action of the heart and arteries is augmented,
and the body becomes warmer.
Thus the coldness, shivering, and consequent heat,
which constitute the first attack of fever, are very plausibly
explained; but in the mode of cure this learned
physician fell into the same mistake with Dr. Boerhaave;
for though spasm is undoubtedly, even according to himself,
an effect, he directs his medicines entirely against it,
as if it were a cause. Thus, forgetting what he had just
before advanced, that the spasm is occasioned by debility,
he recommended the most debilitating medicines
and regimen to cure people already too much debilitated;
and to such practice his enemies alledged that
many fell victims. The theory and practice, however,
still kept its ground; and as great numbers of students
were every year bred up in the belief of it at Edinburgh
College, who carried the principles of their teacher to all
parts of the world, it bade fair for becoming universal.
But, in the midst of this eclat, the whole system received
such a rude shock from the doctrines of John Brown,
though at that time not even M. D. as it hath not yet
recovered.
Though the author of the new system contended, as
much as Dr. Cullen, for the supremacy of the nerves, he
did not upon that foundation attempt to establish his
practice. He considered the living body as one machine,
the whole of which might be acted upon, and always was
acted upon by certain powers. It possesses a certain inexplicable
property called excitability, capable of being
augmented or diminished. Every power which augments
the excitability he called a stimulus; the opposite
would have been a sedative; but according to this
system there is not any sedative, nor can there be one in
nature. The reason is, that excitability itself has no
existence but in consequence of the action of certain
powers called stimulants. The total subduction of these
reduces the excitability to nothing; of consequence no
power can act against it in a state of non-existence.
What other physicians call sedatives, therefore, according
to the new system, are only weak stimulants. The
fallacy of such reasoning is obvious; but as it does not
affect the practice, we shall not spend any time in considering
it further.
On the principles just now laid down, the Brunonian
system divides all diseases to which the human body is
liable into two great classes; the one produced by too
much excitement, the other by too little. The former
contains those diseases by other physicians called inflammatory;
the latter such as are called nervous, putrid,
or all in which the powers of life are too weak, and require
to be supported. This last is supposed to be much
more numerous than the former; and in the cure of
these it was that the founder of the system appeared to
greatest advantage. A most violent altercation took
place between Dr. Brown and the Edinburgh College;
yet, notwithstanding all the influence of the professors, and
their unanimous opposition to the new doctrines, they
found themselves ultimately unable to resist a single man
unsupported either by wealth or reputation. The plausibility
of his system, and its being obvious to every capacity,
overcame every obstacle; so that even the practice
of the Cullenians themselves underwent considerable
alterations. It is not, however, to be denied that the
system hath been considerably improved, or at least altered,
by some of Dr. Brown’s pupils, who have had the
advantage of extensive practice, and of visiting many different
countries; which the Doctor himself never had. His
materia medica was besides exceedingly confined; the
only medicines he had any great opinion of, being laudanum
and ardent spirits. The Peruvian bark he held in very
little estimation, as being a weak stimulus. He seems
to have been unacquainted with the virtues of mercury,
except in the venereal disease, and most probably would
have given laudanum in those cases of fever where mercury
is found by others to be so efficacious. But this
deficiency hath been abundantly supplied by some of
his followers. In a work entitled “The Science of
Life,” published by Dr. Yates and Mr. McLean, practitioners
in the East Indies, we find mercury exhibited
in prodigious doses. As a specimen we shall
select their third case, which was a dysentery. On the
first of September the patient took two grains of calomel
and as much opium every two hours. This was continued
for two days. On the third, the dose was
given every hour; besides which, he had half an
ounce of mercurial ointment with a drachm of calomel
rubbed into his body. Next day the pills were
continued, and the quantity of ointment tripled by
thrice rubbing in. This was continued for three days,
at which time, an eruption on the skin appearing, it was
feared he could not be salivated; this eruption being a
sign that no salivation could be produced. The same
mode of treatment, however, was persisted in. September
7th the calomel in the pills was augmented to
four grains; the warm bath was used, and the ointment
continued; but at night twenty grains of calomel and
six of opium were given every two hours. At the same time
two ounces of ointment, with four of calomel, were ordered
to be rubbed in. Next day, though his pulse
was almost imperceptible, and his extremities cold,
“the medicines were continued as far as circumstances
would admit;” with what view it is not said, nor
indeed is it easy to be discovered. At one in the
morning, however, the patient died; an event not at all
surprising. Our authors excuse themselves for this
failure by saying that the viscera of the patient were
diseased, as was evinced by the impossibility of exciting
a salivation; and “that when a patient is evidently incurable
by the common practice, it becomes the duty
of the practitioner to depart from it.”
No doubt we may readily assent to both these assertions;
but though a patient be evidently incurable by
the common practice, or by any other, there is no
necessity for killing him, or for persevering in a course
of violent medicines that evidently make him worse.
The whole of this case indeed strongly militates against
the doctrine of excitement; for if mercury be such a
powerful stimulus to the powers of life in general, how
comes it to pass that in the present case the unhappy
patient, instead of being in the smallest degree excited,
was prodigiously debilitated, and that from the very
first time of taking the medicines. This will appear
from the following table, exhibiting the symptoms of the
disease as they kept pace with the medicines taken.
Days of the Month. |
Medicines taken. |
Symptoms. |
August 29 &
preceding. |
Ordinary doses of mercury and opium. |
Pain of bowels, and frequent stools, growing worse. |
Sept. 1 & 2. |
Opium and mercury, two grains each, every two hours; besides opiate draughts. |
Still increasing. |
3d |
The opium and mercury as before, but now given every hour; half an ounce of mercurial ointment, with 60 grains calomel. |
Stools very frequent, with violent pain in the bowels; extreme thirst, tongue furred, and no sleep. |
4th |
Pills as usual. Ointmt. thrice rubbed in, once with 120 grains of mercury. |
Vomiting during the night. Tongue brown and furred. |
5th |
Medicines as before. |
Violent pain in bowels. |
6th |
Medicines as before. |
Extreme pain on pressing the arch of the colon; frequent stools, profuse sweats, great dejection of spirits. |
7th |
Pills as before, with four grains of calomel. Mercury in the ointment increased to half an ounce. Warm bath. At night an ounce of mercurial ointment, with two ounces calomel. |
As yesterday. An eruption on the skin. At night incessant stools, with violent pain in the belly; profuse sweat. |
8th |
Pills, ointment & calomel as before. Warm bath thrice. At night two ounces ointment, with four of calomel. |
Incessant stools with violent pain; at night with blood. Extreme debility. |
9th |
Medicines of the same kind, as many as could be taken. |
Stools innumerable; extremities cold, pulse scarce to be felt. |
10th |
|
Death at one in the morning. |
From a consideration of this patient’s symptoms, in
comparison with the quantity of mercury taken, it most
evidently appears, that it acted in no other way than as
an irritating poison; affecting, with extreme violence,
the already diseased intestines, and, instead of exciting
the vital powers of the whole system, manifestly destroying
them. Let it not be imagined, however, that this
case is selected from the rest merely because it was fatal,
or because it affords an opportunity of finding fault with
the practice recommended in the book. It is the only
one in which the mercury had a fair trial; and even
here it was not very fair, as being conjoined with a great
quantity of opium. In the other cases, which terminated
favourably, the mercury was overpowered by such
horrible doses of opium, that we cannot tell which medicine
had the greatest share in the cure; besides, that
in other cases the patients were allowed the free use of
wine, which we all know to be a powerful stimulant and
cordial; but it is not said that the poor man, whose case
is above related, had a single drop of wine, or any thing
else, except opium, to support him against the action of
such a violent medicine.
On this case it is of importance still to remark, that it
affords, in the strongest manner, an argument against
what our authors say, p. 86, that “mercury acts by
supporting the excitement of the whole body, it invigorates
each particular part; and thus occasions, to
a certain extent, the regeneration of those organs
which may have been injured by disease.” In the instance
adduced, there is no evidence of a stimulus upon
any other part of the system than the bowels, which
were already debilitated or diseased in such a manner
that they could not bear it. The system in general,
instead of being excited, was sunk and debilitated from
the very first moment, until at last the excitement terminated
entirely by the patient’s death. But further:
There is very little probability that mercury or any other
medicine whatever can prove a general stimulus, and
that for the following reasons.
1. No medicine can assimilate with the substance of
the body. Medicines properly so called are here alluded
to. Food or drink of any kind taken for the support of
the body while in health, however they may act medicinally
upon occasions, are excepted.
2. The body is composed of many various substances,
each differing in its nature from the other. The
nature of the medicine, whatever it may be, is uniform,
and cannot act upon substances of different kinds in an
uniform manner; and without this there can neither be
an universal stimulant, nor an universal debilitant.
3. All medicines, being incapable of assimilation with
the body, must be considered, when taken into it, as foreign
matter; and the introduction of them at any rate
is in fact the creating of a disease. This is evident from
multitudes of instances where people by quacking with
themselves, and taking medicines unnecessarily, have
destroyed their health.
4. As every medicine has one peculiar nature, and
one mode of action in consequence of that nature, it
must, when introduced into the body, where there are
fluids of various natures, act upon one of them more
than the rest; and this may be called the chemical action
of that medicine upon the body.
5. In consequence of the chemical action of the medicine,
the mode by which it is expelled out of the body
will be different; for, as all medicines are extraneous
substances, they must be sent out of the body as fast
as possible; and it is their action upon one particular
part which promotes their expulsion. Thus, if from
the nature of the medicine it acts in a certain way upon
the stomach and bowels, it will vomit or purge, or perhaps
both; and by this action it is expelled from the
body, along with whatever other matters happen to be
in the stomach or intestines; and thus medicines do
good only accidentally; for mere vomiting or purging
are most certainly diseases; but where noxious
matters exist in the bowels, and do not naturally excite
these operations, an emetic or purgative is unquestionably
useful. Here the authors of the Science of Life
reason differently; and it is worth while to refute their
argument, as being the foundation of such tremendous
practice as nobody of common sense would choose to be
the subject of. Of tartar emetic they speak in the
following terms. “That tartar emetic is a stimulant of
very high power, is evident from the small quantity of
it which produces the state of indirect debility that
occasions vomiting. It should be given in such a
manner as to increase and to support the excitement.
But this will be found difficult, as the duration of
its action seems to be even shorter than that of opium.
If its action does not continue more than a quarter
of an hour, might it not be repeated at such short
intervals, and the doses so reduced as to allow the
establishment of the indirect debility?” This is
arguing in a circle. They first suppose that vomiting is
occasioned by indirect debility, that is, the weakness
produced by an excessive stimulus to the whole system,
as in cases of drunkenness; and then, from the existence
of vomiting, they prove that a general stimulus had
pre-existed. The cases, however, are widely different.
In cases of drunkenness, the person feels himself at first
exhilarated, alert and active, which shows the existence
of a general stimulus. But who has ever found himself
exhilarated by taking a dose of tartar emetic? Yet in a
general excitement it is absolutely necessary that this
exhilaration should take place, because it is an inseparable
consequence of an addition of vital power, let it
come in what way it will. Thus we know that if a
person happens to be much exhausted by fatigue and
abstinence, he will be exhilarated and his strength augmented
by a single mouthful of meat, as well as by a
glass of wine. This shows that both these are general
stimulants to the system; but what medicine have we
that will produce similar effects? Perhaps opium
comes the nearest in the whole materia medica; but
the uneasiness it occasions in the stomach manifests a
greater action upon it than the other parts; for if the
whole body were equally excited, the withdrawing of the
stimulus, or its naturally losing its force, could only
have the same effect with fasting or fatigue; but the
debility of the stomach, the confusion of the head, and
other effects which attend a dose of opium, demonstrate
that it acts partially, and not equally over the whole
body. The Science of Life indeed says that these effects
are owing to the improper omission of the medicine, or
not repeating the doses in due time. This may be;
but no improper exhibition of food, or want of due repetition,
will produce such symptoms; which undoubtedly
is a proof that food stimulates the system in one
way, and opium in another.
6. If any medicine could be found that acted as an
universal stimulus or exciter of the whole system, it
could not like others be expelled, by any particular evacuation;
but, by destroying the balance between the
force of the acting powers and the subject on which they
act, would most certainly kill, unless very powerful
means were used to counteract its effect. The only
stimulant we are acquainted with which acts equally on
the whole system, and which can be readily exhibited as
a medicine, is that pure kind of air called by Dr.
Priestley dephlogisticated, by Scheele empyrean, and by the
French chemists and their followers oxygen. The exciting
powers of this air, when breathed instead of the
ordinary atmosphere, are astonishing. It not only augments
the appetite, but the power of the muscles, and the
inclination to use them; so that without any intoxication
or delirium the person cannot refrain from action; and
it not only exhilarates the spirits in an extraordinary
manner, but beautifies the face. Did the cure of diseases
therefore, or any set of them, depend on mere excitation,
no other medicine but oxygen would be necessary.
What effects it may have in diseases of debility is
not yet ascertained; but to persons in health it certainly
proves fatal: their bodies are unable to bear its powerful
action, and of consequence they waste, and would die of
consumptions, if its effects were not counteracted. Nor
is this at all an easy matter; for Dr. Beddoes informs us
that, by breathing this air for a short time each day, only
for three weeks, he found himself in great danger of a
consumption, and was obliged to use much butter and
fat meat in his diet, besides giving up the use of the air
altogether, in order to get clear of its mischievous
effects.
Another mode of stimulating or exciting the whole
system is, by putting into it a larger quantity of blood
than it naturally contains. This is entirely similar to
the breathing of oxygen; especially if arterial blood be
used, which has already imbibed its spiritous part from
the atmosphere. In the last century the transfusion of
blood was proposed not only as a mode of curing diseases,
but of restoring old people to youth; and Dr.
McKenzie, in his Treatise on Health, quotes from the
memoirs of the Academy of Sciences several instances of
the blood of brute animals being infused into human
veins, without any inconvenience. It seems, however,
not only a bold but an unnatural attempt to use the
blood of beasts for such a purpose; and, however lavish
mankind may be of their blood upon certain occasions,
it is to be feared that there are few who would be willing
to spare any to relieve another from sickness; but indeed
little can be said about the practice; as, on account of
some bad consequences, or failures, it was forbidden by
the king of France, and by the pope’s mandate in Italy,
and has now fallen into disuse. In a paragraph at the
end of Heister’s surgery (4to edition) it is asserted that
the transfusion of blood was productive of madness.
Dr. Darwin, however, in his Zoonomia, still proposes
the transfusion of blood as a remedy, and even describes
a convenient apparatus for performing the operation.
In one part of his work he says, “Might not the
transfusion of blood, suppose of four ounces daily, from
a strong man, or other healthful animal, as a sheep or an
ass, be used in the early state of nervous or putrid
fevers?” In another place he mentions his having proposed
it to a gentleman whose throat was entirely closed
up by an incurable swelling, so that he could swallow nothing.
This is a disease not very rare, and which always
must be fatal; because the patients, though not affected
by any sickness, die of hunger; and, to relieve them
from this miserable situation, extraordinary attempts are
not only allowable but laudable. The Doctor proposed
to his patient, “to supply him daily with a few
ounces of blood taken from an ass, or from the human
animal, who is still more patient and tractable, in
the following manner: To fix a silver pipe, about an
inch long, to each extremity of a chicken’s gut, the
part between the two silver ends to be measured by
filling it with warm water; to put one end into the
person hired for that purpose, so as to receive the
blood returning from the extremity; and when the
gut was quite full, and the blood running through the
other silver end, to introduce that end into the vein
of the patient, upwards towards the heart, so as to
admit no air along with the blood. And, lastly,
to support the gut and silver ends on a water plate
filled with water of 98 degrees of heat; and, to measure
how many ounces of blood were taken away, to
compress the gut from the receiving pipe to the delivering
pipe.” The gentleman desired a day to consider
of this proposal, and then another; after which he
totally refused it, saying that he was now too old to
have much enjoyment of life, and that, being so far advanced
in a journey which he must certainly accomplish
sooner or later, he thought it better to proceed than return.
The Doctor informs us that he died a few days
afterwards, seemingly very easy, and careless about the
matter. One experiment of this kind I have been witness
to; not indeed on a human creature, but on a calf. This
creature received into one of its jugular veins a considerable
quantity of blood from the carotid artery of another,
nearly of the same age (about a month, or little more.)
It was impossible to say any thing about how much was
transfused; only the bleeding was continued till the
animal which lost the blood began to shew signs of faintness.
The artery was then tied up, and the orifice in
the jugular vein closed. The calf which had lost the
blood appeared very languid and faint, but lived a few
days in a drooping state; when it either died of itself, or
was killed, as being supposed past recovery. The other,
which had received the blood, appeared to be in every
respect highly excited. It became playful, even in the
room where the operation was performed, its eyes assumed
a bright and shining appearance, and its appetite
was greatly increased. Thus it continued for about a
fortnight; appearing all the time to be in high health, and
eating much more than usual; but at last died suddenly
in the night. From these effects on healthy subjects, however,
we cannot infer what would happen in such as are
diseased; but it is plain that if the cure of diseases were to
depend upon mere excitation, the means are in our power,
without any local irritation, which always must take
place in some degree by the use of ordinary medicines.
This path is not absolutely untrodden: the pneumatic
practitioners of the present day have tried oxygen in
consumptions, and found it pernicious; and Dr.
McKenzie informs us that the transfusion of blood was
tried ineffectually in the same.
7. As all the medicines usually prescribed at present
are only to be accounted partially stimulant, or as acting
upon particular parts of the system, we see that some
may promote one evacuation, and some another; while
all produce some change in the organization, which may
prove useful or detrimental, may increase the disease or
cure it, or may produce another, according to the judicious
or injudicious application. But for a knowledge
of all this we must be indebted to experience: there is
not a theory on earth that can lead us a single step.
Before we dismiss the consideration of medical theories,
however, it will still be necessary to give some account
of the new system as it hath branched out in various
ways: for though the fundamental principle is now
received by a great number of physicians, yet the superstructure
is exceedingly different from what Dr. Brown
himself erected and, indeed, from the very same principles
we find conclusions made as directly opposite to
one another as can be expressed in words. Drs. Yates
and McLean, for instance, at Calcutta in the East Indies,
have concluded that the plague “is a disease of a very
high degree of exhaustion;” which Dr. Brown would
have called debility. Dr. Rush at Philadelphia, proceeding
also upon the Brunonian principles, determines
it to be the most inflammatory of all diseases,62 and
which Dr. Brown would have called a disease of excitement.
These two doctrines are, in every sense of the
word, as distant from one another as east from west.
Let us then consider both, if any consideration can avail
us on the subject.
By the ancients it was supposed that diseases were
occasioned by something either bred in the body or received
into it, and that the power of nature produced,
during the course of the disease, a certain change in this
matter, called coction, or concoction; which, if we please,
we may express by the English word cooking. The
matter of the disease, called also morbific matter, thus
cooked, was in a state proper for expulsion, and was
therefore thrown out by sweat, vomit, stool, &c. or it
might be expelled artificially, which could not have been
attempted with safety before. Modern systems deny
the existence of morbific matter, and resolve all into an
affection of the nerves, according to Dr. Cullen by certain
sedative causes, but according to Dr. Brown by
an accumulation in some cases, and an exhaustion in
others, of the excitability or excitement of the body.
The Science of Life commences with stating what they
suppose to be an improvement of the Brunonian principles,
and from which the following account of the origin
of diseases is extracted. “Upon the different states of
excitability depend all the phenomena of health and disease.
There are three states of the excitability. 1. The
state of accumulation; when a portion of the usual
stimuli is withheld. . . . When a portion of the
usual stimuli is withheld, the excitability accumulates,
and the body becomes susceptible of impression in the
direct ratio of the subduction. This state constitutes
diseases of accumulation, or of direct debility. 2. The
middle state; when the excitability is such that the application
of the accustomed degree of exciting powers
produces tone or health. 3. The state of exhaustion.
When the application of stimuli has been greater than
that which produces healthy action, the excitability is
exhausted, and the body becomes less susceptible of
impression in the direct ratio of the excess. This state
constitutes diseases of exhaustion, or of indirect debility.
The states of accumulation and exhaustion of the excitability,
in their different degrees, constitute all the
diseases to which living bodies are subject.”
Here the chime runs on the word excitability, which
is not defined. If we call this property life, then we are
only informed, that, as life is more or less vigorous,
the body enjoys a greater or smaller degree of health;
which we know without any medical instructor. If, instead
of the accumulation and exhaustion of excitability,
we take the original doctrine of excitement and debility
laid down by Dr. Brown himself, we are nothing better.
The whole theory is lost for want of the definition of a
single word. As long as excitability remains an unknown
property, we can explain nothing by it. We may indeed
vary our terms. We may call it nervous influence
with Dr. Cullen, or sensorial power with Dr. Darwin;
but we shall still be as much in the dark as ever; and
all that can be made out of our theories, when our language
is decyphered, must be, that sometimes people are
well, and sometimes they are sick!
Dr. Rush, in his Treatise on the Proximate Cause of
Fever, adopts in part Dr. Brown’s system pretty nearly
as the author himself laid it down. “Fevers of all
kinds (says he) are preceded by general debility. This
debility is of two kinds, viz. direct and indirect. The
former depends upon an abstraction of usual and
natural stimuli; the latter upon an increase of natural,
or upon the action of preternatural, stimuli upon the
body. . . . Debility is always succeeded by increased
excitability, or a greater aptitude to be acted upon by
stimuli. . . . The diminution or abstraction of one
stimulus is always followed by the increased action of
others.” Here it is evident we are as much in want
of definitions as ever. We know neither what excitability
is, nor what debility is, and yet they are both held out
as the causes, and proximate or immediate causes, too, of
symptoms produced by things quite obvious to our
senses. Thus cold and heat, with which we are daily
conversant, are only called the predisposing causes of fever;
while debility and excitement, words to which we have
no meaning, are said to be the proximate cause. It
would certainly be better to throw away such words altogether,
and say that cold, heat, &c. cause fevers, without
troubling ourselves farther about the matter.
It remains now to take into consideration the pneumatic
theories, founded upon the discoveries made by
Dr. Black, Dr. Priestley, Lavoisier, and others, concerning
various kinds of aerial fluids, or gases,63 as they are
also called. Some of these, particularly that afterwards
called fixed air, were discovered by Van Helmont.
Considerable advances were made by a German chemist,
named Mayow, in the last century; but his book had
fallen into such oblivion that his name was scarce ever
mentioned, until his discoveries were repeated, and still
greater advances made by others. Dr. Hales obtained
air from a great many different substances, but was unable
to ascertain any thing concerning its nature. Dr.
Black of Edinburgh laid the foundation of pneumatic
chemistry, by discovering that a certain species of air is
capable of being absorbed by earths of different kinds,
and that many very heavy substances owe at least one
half of their weight to this condensed air. The discovery
was accidental. Wishing to obtain a very pure
and white lime, he had recourse to the fine white earth
called magnesia alba. Some of this he distilled with a
heat sufficient to make the vessel red hot. Only a very
small quantity of water came over, but the magnesia had
lost almost two thirds of its weight. This immense loss
was found to arise from an emission of air during the
operation; and by other experiments it was likewise
found that the air might be transferred from one portion
of magnesia to another from which it had been previously
expelled; that the existence of this species of air
in certain bodies was the cause of that fermentation
which takes place when any acid is poured upon them,
as vinegar upon chalk or potash. Hence if any of these
substances be deprived of its air, it will not any longer
ferment in this manner. It must not be forgot, however,
that when air thus unites itself with any terrestrial
substance it no longer has its former properties. It is
reduced exceedingly in bulk, and in proportion to this reduction
only the body is increased in weight; and therefore
though we say that the air is absorbed, we must still remember
that only one part of it is so, and that by far
the least considerable in bulk. A violent fire will always
expel the air again, and restore it to its former bulk;
and again the condensation or absorption of the air is
always attended with the production of heat. This last
property was not much attended to by Dr. Black, but
others have observed it; and the late Dr. Charles Webster
of Edinburgh published a theory in which he maintained
that condensation was in all cases the cause of
of heat. But, however true it may be that condensation
of any kind is followed or accompanied by heat, it is
evidently necessary to know the cause of the condensation
also, otherwise we make no advance in solid theory.
The aerial fluid, discovered by Dr. Black, was one
of those most commonly met with. He called it fixed
air, from its property of adhering or fixing itself to different
bodies. It was found to be the same with that
which had been discovered by Van Helmont, and by
him named gas sylvestre (spirit of wood)64 or the fume
of charcoal; it was found to be the same with the steam
of fermenting liquor, and with that very frequent and
dangerous vapour, met with in coal mines, called in
Scotland the choke-damp. Like other discoveries, this
was quickly pushed beyond its proper bounds, and applied
to the solution of phenomena which it could not
solve. Dr. MBride, particularly, supposed it to be the
bond of union between the particles of matter, or in
other words the principle of cohesion itself. It was also
supposed to be the substance of those scorching winds,
called samiel, met with in Asia and Africa, and which
sometimes prove fatal to travellers. The pernicious vapours
called mofetes, which sometimes issue from the old
lavas of Vesuvius in Italy, were likewise supposed to be
the same;65 but of this, particularly with regard to the
samiel, there seems to be no sufficient evidence.
The industry of other experimenters did not long
leave theorists without abundance of materials upon
which they might exercise their talents. It is impossible
in this place to assign to each his proper rank in the
way of discovery, or indeed to mention their names.
Dr. Priestley has distinguished himself far above the rest.
He not only repeated and improved Dr. Black’s experiments
on fixed air, but likewise found out a number of
other kinds; particularly that from animal substances in
a state of putrefaction, which is so pernicious to living
creatures, insects excepted; for these last will thrive
amazingly in air that would prove certain death to a
man. He also discovered that this kind of air, and
some others, were absorbed by vegetables, and thence
inferred the use of vegetables in purifying the atmosphere.
He even analysed the atmosphere itself, and found that
it consisted of two different kinds of fluids, one of which
he called dephlogisticated, the other phlogisticated air.
The former was found to support animal life for a time,
the latter to destroy it instantly. Their effects upon
fire were the same; the former exciting the most
vehement heat and bright flame, the latter extinguishing
a fire at once.
The fame of Dr. Priestley’s discoveries quickly reached
the continent of Europe; the French chemists repeated
his experiments with improvements, as they thought;
and indeed certainly made many curious discoveries.
Lavoisier was particularly remarkable for his numerous
and accurate experiments; but, by his changing entirely
the language of former chemists, and substituting a set
of new terms of his own invention, he certainly entailed
the greatest curse upon the science it ever met with.
It belongs not to this treatise to give an account of his
system farther than to say, that, from the immense
proportion of condensed aerial matter found in most
terrestrial substances, he and his followers were led to
conclude, that different species of air constitute almost
the whole of the terraqueous globe. Water particularly
they have absolutely and most positively determined to
be a composition of two airs condensed, viz. the dephlogisticated
and inflammable, which they call oxygen and
hydrogen. However, this doctrine is still opposed by
Dr. Priestley and some others.
In the midst of so much theory, and so many new
and surprising discoveries, it would have been wonderful
indeed if the science of medicine had kept free from
innovation. It did not: the new chemistry, with all
its formidable apparatus of hard words, was introduced,
and thus the study of the science, already very difficult,
was rendered still more so. In passing this censure upon
the modern nomenclature, as it is called, I am sensible
that I must rank with the minority; nevertheless, I have
the satisfaction of finding that I am not altogether singular.
Dr. Ferriar, in the preface to his second volume,
complains, “that, with every attempt towards the formation
of a system, new applications of words are introduced,
which, though desirable in the art of poetry,
are very inconvenient in pathological books, especially
when this is done to give an air of novelty to
old theories and observations. For, between the ancient
language, which practitioners cannot entirely
reject, and the new dialect, which they cannot wholly
adopt, the style of medical books is reduced to a kind
of jargon, that the author himself may possibly understand,
but which his readers find it very difficult to
unriddle. Hence results a neglect of medical literature,
and hence the pernicious habit of regarding as
new whatever has not appeared in the publications of
the last half century.” To the same or a similar purpose,
in the preface to his first volume, he cites Quintilian.66
“Some have such a multitude of vain words,
that, while they are afraid of speaking like other people,
by a kind of affected elegance, they confound every
thing they have to say with their immense loquacity.”
The pneumatic system naturally arose from a consideration
of the composition of the atmosphere we
breathe. Finding this fluid to be composed of two
others, the one of which would preserve life for some
time at least, and the other instantly destroy it, it became
natural to think that diseases might be produced
by any considerable variation in the proportion of these
ingredients. An instrument was soon invented by
which any considerable variation in this respect might
be discovered; but upon trial this was found to be of
very little use. Dr. Priestley himself tried, by means of
this instrument, some very offensive air which had been
brought from a manufactory, and could find no remarkable
difference between it and that which was accounted
pure. Still, however, it was evident that by increasing
very much the proportion of one of the ingredients,
some considerable alteration might be produced,
which could not but be perceptible in the human body;
and this led to the application of aerial chemistry to disorders
of the lungs. The mixture chosen for this purpose
was pure dephlogisticated (oxygen) with inflammable
air (hydrogen;) and, though this has not been
known to effect a radical cure, it certainly has given
relief in many cases. In fevers also the application of
fixed air (carbonic acid) hath been found advantageous;
but with regard to oxygen and some others we have not
yet a decided instance of their good effects in any case.
Dr. Beddoes indeed is of opinion that it would be of
service in the sea-scurvy; but in this (whether his conjecture
be right or wrong) the theory is certainly erroneous,
as shall presently be evinced.
In considering the pneumatic system it is evident that
modern chemists have fallen into the same error with
their predecessors, viz. of supposing that every thing
which by the force of fire or otherwise they could
produce, from any substance, previously existed in it.
Hence, as from a piece of bone for instance, a chemist
can produce water, salt, oil and earth, it was supposed
that these four were the principles or elements of the
bone. But this was false reasoning; for if these were
really the chemical principles, they ought to have been
able to produce some kind of bony substance by mixing
them together after they had been distilled. But no
such thing could be done; and though we should add
to the mixture the whole quantity of air emitted during
the distillation, and which escaped the notice of ancient
chemists, our success would be no better. In like
manner, because in certain circumstances oxygen is
obtained from the flesh of animals, it has been concluded
that it necessarily exists as an ingredient in their
bodies while living; and that, if this kind of air happens
to predominate, the animal will be affected in one way,
or if hydrogen prevail, in another. But though we have
already quoted Dr. Girtanner with approbation as
having obtained oxygen gas from fresh meat, yet this
does not by any means prove to us that it exists in flesh
as one of its component parts. Even in the Doctor’s
experiment it was necessary to expose the flesh to the
atmosphere in order to procure the gas by distillation;
which undoubtedly must excite a strong suspicion that
the air in question comes from the atmosphere itself; and,
if this is the case, it is not reasonable to suppose that a
disease could be cured by any addition of oxygen to the
solid parts; because, though sound flesh may have an
inclination to absorb this kind of air, we do not know
whether it would have such a property of absorption in a
diseased state. Indeed in the scurvy, which Dr. Beddoes
chooses as an example, experiment seems to determine
in favour of fixed air rather than any other. But let us
hear Dr. Girtanner himself, who has at large discussed
this subject in two memoirs; one upon the laws of
irritability, and another on the principle of irritatibility.
In these memoirs we find the Brunonian doctrine set
forth with such silence in regard to Dr. Brown himself,
that some have not scrupled to charge Dr. Girtanner
with literary theft; but this is a matter which belongs
not to us to consider: the theory may be very good,
whether stolen or not. He changes the word excitability,
used by Dr. Brown, for irritability; but hath the
misfortune of not being able to tell us what he means
by it. He goes on, however, to distinguish the three
states of tone or health, accumulation, and exhaustion, as
other Brunonians do. Health, he says, in a fibre “consists
in a certain quantity of the irritable principle
necessary for its preservation. To maintain this state,
the action of the stimulus must be strong enough to
carry off from the fibre the surplus of this irritable principle
which the lungs and the circulation of the
fluids are continually supplying. For this a certain
equilibrium is necessary between the stimuli applied
and the irritability of the fibre, in fine that the sum of
all the stimuli acting upon it may be always nearly
equal; powerful enough to carry off from the fibre
the excess of its irritability, and not so strong as to
carry off more than this excess. . . . When the
sum of the stimuli acting upon the fibre is not great
enough to carry off all its excess of irritability, the
irritable principle accumulates in the fibre, and then
it is found in that state which I call the state of accumulation;
the irritable principle accumulates in the
fibre, its irritability is augmented, and the stimuli produce
much stronger contractions than when the fibre
only retains its tone. . . . When the sum of the
stimuli acting upon the fibre is too great, the fibre
is deprived not only of the excess of its irritability, but
also of some portion of the irritable principle necessary
for the tone of the fibre; or, more properly speaking,
the fibre loses more irritability than it receives, and,
of course, in a short time finds itself in a state of exhaustion;
and this exhaustion will be either temporary,
or irreparable.”
Here it is evident that we have nothing but Dr.
Brown’s system, without the least explanation to render
it more intelligible. A definition is still wanting. This
invisible and incomprehensible property of irritability
ruins our whole fabric; nor can the deficiency be supplied
by human art or skill: of consequence we must
abandon this part of the system entirely, and come to
something more cognizable by our senses. It is impossible,
however, to pass over in silence the amazing inattention
of the author, in imagining that on such unintelligible
principles he could explain other phenomena.
“In the state of temporary exhaustion (says he) the fibre
loses its tone, and fails for want of irritability. The
application of a stimulus while it is in this state will
not make it contract. Provided the stimulus be not
very strong, it will produce no effect at all, but in a
short time the irritable principle will accumulate afresh
in the fibre, and then it will again contract. It is
only by little and little that the fibre recovers its irritability.
This truth, I dare venture to say, is as new
as it is striking. It unfolds a vast number of phenomena
hitherto inexplicable.” Here we have nothing
but the pompous declaration of a fact already
well known; viz. that not only a fibre, but the whole
body, may be in a state of temporary insensibility, and
yet recover either of itself or by the use of external means.
How many people have fallen into a syncope, and yet recovered!
How many limbs have become paralytic, and
in time recovered their sense and motion! Yet this is
all that we are informed of with so much parade and
assumption of novelty. We know that when a person
is in a faint he is insensible to ordinary stimuli, though
very strong ones will rouse him; but what can we infer
from this? Nothing; only we see it is so. Does it avail
us any thing to be told that during the time of fainting
the irritability is exhausted, and “in a short time the
irritable principle will accumulate afresh;” in which
case the patient will no doubt recover, unless he happens
to be dead, which is the true meaning of an irreparable
exhaustion of the irritability.
In speaking of the principle of irritability he expresses
himself in the following manner. “I think that the
oxygen is absorbed by the blood, and that the venous
blood is oxygenated in the lungs during respiration.
The most celebrated naturalists and chemists are of a
different opinion: they think that the oxygen does
not combine with the venous blood. According to
them, this last loses carbon and hydrogen, and recovers
the bright colour natural to it, without absorbing
any thing from the atmosphere. . . . After having
a long time attended the phenomena of respiration,
and made many experiments upon this subject,
I think it may be concluded that one part of the
oxygen of the vital air combines with the venous
blood, of which it changes the black colour, and
makes it vermilion;67 the second part of the oxygen
unites with the carbon contained in the carbonic-hydrogen
gas, which exhales from the venous blood, and
forms carbonic acid air; a third part unites with the
carbon of the mucus, contained in great quantities in
the lungs, and which is continually decomposing; this
part also forms carbonic acid air; a fourth part of the
oxygen combines with the hydrogen of the blood to
form water.”
On this theory I shall only observe, that though I lay
claim to the former part, I allow the Doctor all the latter
part to himself; particularly where he speaks of the
formation of water to be exhaled during respiration. The
air in question consists of two parts, like fixed air already
mentioned. One of these is capable of being attracted,
condensed, or united with certain substances; the other
vanishes, leaving no other traces of its having ever existed,
but heat, greater or less according to circumstances.
When the air is taken into the blood, one part of
it undoubtedly combines with something thrown out by
the lungs, and forms fixed air, of which our breath contains
a considerable quantity. We know certainly that
the condensable part of fixed air is formed out of the
condensable part of the oxygen, with certain additions.
As therefore great part of this condensable oxygen is
thrown out in fixed air at every expiration, it is natural
to suppose that all of it is so: at least we cannot know
the contrary without a series of very difficult and tedious
experiments, which have never been made by Dr. Girtanner
or any body else. But if the whole of this condensable
part be thrown out, none can enter the blood
by the breath; and consequently whatever true oxygen
may afterwards be expelled from that fluid, must be a
factitious substance, formed either during the artificial
process, used for distilling it, or by a natural process In
the body itself. It is not therefore at all probable that
the oxygen which flesh emits in distillation can be derived
from the air by respiration.
Another and more probable source is the food and
drink we take; all of which are more or less impregnated
with air of different kinds, particularly fixed air.
This, we know, very readily condenses, and certainly
will do so when taken into the body. In this state it
not only may, but certainly will, pass into the blood,
and through all the different parts of the body, until,
having accomplished its purpose, whatever that may be,
it is thrown out by insensible perspiration, as has been
already explained.
The conclusions drawn by Dr. Girtanner from his
experiments are, 1. That the change of colour which
the blood undergoes during the circulation is not owing
to its combination with hydrogen air68. 2. The deep
colour of the blood in the veins is owing to the carbon it
contains. 3. That the vermilion colour of the arterial
blood proceeds from the oxygen with which the blood
is conjoined during its passage through the lungs.
4. That respiration is a process exactly analogous to the
combustion and oxydation of metals; that these phenomena
are the same, and to be explained in the same manner.
5. That, during circulation, the blood loses its oxygen,
and charges itself with carbonic hydrogen air, by means of
a double affinity. 6. That, during the distribution of
the oxygen through the system, the heat which was
united with this oxygen escapes; hence the animal heat.
7. That the great capacity of arterial blood for heat is
owing to the oxygen with which it is united in the
lungs.
On these propositions, which constitute in a great
measure the fundamental principles of the doctrine of
oxygenation of the human body, we may remark,
1. Nobody can reasonably suppose that hydrogen air
is the cause of the dark colour of the blood in the veins,
because there is no source from which it can be derived;
and, besides, it is certain that no kind of air can exist in
its elastic state in the blood, without destroying the life
of the animal. Some experiments proving this are
given by Dr. Girtanner himself. It is true that an aerial
vapour, of the nature of fixed air, exhales from the
body by insensible perspiration; but there can be no
doubt that this receives its elasticity only at the surface
of the body, and is expelled the moment it is formed.
It has indeed been proved, by undeniable experiment,
that no air of any kind exists in the larger veins; because
a portion of a vein, included between two ligatures,
being cut out, and put under the receiver of an air-pump,
does not swell in the least when the air is exhausted,
which yet must be the case, did the smallest
quantity of elastic air exist in it.69
2. When the Doctor asserts that the dark colour of
the venous blood is owing to the carbon it contains, he
is in the first place chargeable with the error of former
chemists, who supposed that every thing which could be
extracted from any substance by fire, existed previously in
it, in that very form in which it is extracted by the fire;
and in the second place he speaks entirely at random,
without even a shadow of proof. Nay, he himself tells
us, that he has repeated two of Dr. Priestley’s experiments,
which in the clearest manner demonstrate, that
neither the addition nor the abstraction of carbon, or
any thing else, give this dark colour to the venous
blood. “A small glass tube (says he) filled with arterial
blood, of a bright vermilion, was sealed hermetically,70
and exposed to the light. The blood changed
its colour by degrees, and in six days became
black as venous blood. The same experiment was
repeated, with this difference only, that the tube was
exposed to heat, and not to the light. The blood
became black in a shorter time.” In these experiments
it is plain, that if the blood contained oxygen at
first, it did so at the last; the same with regard to carbon.
How came it then to pass, that without either
evaporation of the former, or addition of the latter, the
change should be produced? If the oxygen imbibed by
the blood in the lungs was sufficient to produce the red
colour, why did it not preserve it? The case here is precisely
similar to what happens with the calx of silver.
When that metal is dissolved in aqua fortis, and again
reduced to a solid form, it appears as a white powder,
and will preserve its colour if carefully kept from the
light; but if a vial be filled with it, and exposed to the
sun, that side on which the light falls will in a short
time become black, and this though the vial has been
ever so carefully sealed.71 Formerly, chemists had a method
of accounting for this appearance, as well as that
of the venous blood, by what they called the evolution
of phlogiston: but now that the very existence of phlogiston
is denied, we are deprived of this resource. But,
whatever words we may use, it is plain that in neither
case have we any ideas affixed to them which can make
the matter at all more intelligible than it was before.
But with regard to the blood, we are at a considerable
loss to understand what the natural colour of it is; and
indeed the question can only be determined by examining
the blood of a fœtus which has never breathed.
If the arterial blood of such a fœtus be of a dark colour,
resembling that in the veins of a grown person, we must
look upon this to be natural to it, and we may as well
inquire why a rose is red, or an iris blue, as why the
blood is of a dark, and not of a bright red. But, if we
find this dark red change to a bright scarlet in the arteries,
as soon as the child has breathed, we have as much
reason to conclude that the air occasions this superior
redness, as that an acid is the cause of a red colour in
the syrup of violets, or an alkali of a green colour in the
same. Experiments are yet wanting to determine this
matter. Mr. Hunter has observed that “in such fœtuses
as convert animal matter into nourishment, they
most probably have it (the colour of the blood) influenced
by the air, such as the chick in the egg, although
not by means of the lungs of the chick, we
find the blood, in the veins of their temporary lungs,
of a florid colour, while it is dark in the arteries.”—The
probability therefore is, that the blood is naturally
dark; by the elastic principle of the oxygen that it is
rendered brighter; and that, this elastic principle being
expended in the course of circulation, the fluid reassumes
its original colour.
3. Though enough has already been said to evince
that the superior redness of the arterial blood is derived
from oxygen gas, we shall still quote two instances from
Mr. Hunter’s Treatise on the Blood, which set this
forth in the clearest manner; and these instances are the
more remarkable, because they demonstrate the phenomena
not of the dead, but of the living body. 1. A gentleman
in an apoplexy, who seemed to breathe with
great difficulty, was bled in the temporal artery. The
blood flowed very slowly, and for a long time. It was as
dark as venous blood. He was relieved by the operation;
but, on opening the same orifice in two hours,
the blood flowed of the usual florid colour. 2. A lady
in an apoplexy was treated in the same manner, and Mr.
Hunter observed, that when she breathed freely, the
blood from the temporal artery assumed a bright red
colour; but when her breathing was become difficult,
or when she seemed scarce to breathe at all, it resumed
its dark colour, and this several times during the operation.
4. Respiration is not, as Dr. Girtanner says, a process
similar to the combustion and oxydation (the calcination)
of metals. Some of these by calcination, and
all of them in the opinion of Dr. Girtanner, unite with
the condensable part of the oxygen contained in the air,
while the elastic part is dissipated in flame or heat. The
reverse of this takes place in breathing; for here the
elastic part of the oxygen unites with the blood, and
makes it warm, while the condensable part, uniting with
certain particles to be thrown off from the body, passes
away in fixed air. Thus the process of respiraton does not
resemble the calcination of a metal (at least according
to our author’s opinion of that operation) but rather the
inflammation of some combustible substance; for in
both cases a certain quantity of carbon is found to be
united with the basis of oxygen in the atmosphere, and
thrown off from the place of combustion; and thus a
quantity of fixed air is produced from every burning
substance. Just so is it with respiration. If the condensable
part of the oxygen combined with the blood,
then no fixed air could be produced; or if any part of
the oxygenous base was absorbed, it must certainly be
known by a proportional deficiency in the quantity of
fixed air produced. But there are no experiments made
with accuracy sufficient to determine this point. It is
true that many very able physiologists, as Borelli, Jurin,
&c. have been of opinion, that part of the air is absorbed
in respiration; but when we come to particulars nothing
can be determined. Dr. Hales by experiment
found the quantity absorbed to be a sixty-eighth part of
the whole quantity inspired; but, on account of supposed
errors, he states it only at an hundred and thirty-sixth part.
Between these two the difference is so enormous, that
we know not how to draw any conclusion from them.
The French chemists are more decisive, and agree pretty
well with one another. Chaptal calculates it at three
hundred and fifty-three, and La Metherie at three hundred
and sixty, cubic inches in an hour. Allowing these experiments
to be just, the next question is, what part of
the air is absorbed. Lavoisier says, that it is the oxygenous
base, or the same with that which is absorbed in
the calcination of mercury. But how comes he to know
this? Surely not in the same way that he determines the
absorption of it by mercury. In the latter case he takes
a certain quantity of mercury, includes it in another
known quantity of oxygen air, and heats the metal by
means of a burning-glass or otherwise: the consequence
is, that the air is absorbed, the mercury loses its fluidity,
and is increased in weight. The metal gains the whole
weight of the air absorbed; and, by another process, all
the air and all the metal, or very nearly so, may be obtained
in their original form. This experiment is so
decisive, that nothing can be said against it with any shadow
of reason; but who hath made, or who can make,
similar experiments with the blood of a living man? Such
experiments indeed might be made, if insensible perspiration
did not stand in our way. Common atmospherical
air is about eight hundred times lighter than water. A
cubic inch of distilled water, according to Dr. Kirwan,
weighs two hundred and fifty-three grains and a quarter.
Oxygen air is somewhat lighter than common air: we
shall therefore suppose that six hundred inches of it are
equal to an inch of water. If then the blood absorb
three hundred and sixty inches of air in one hour, it will
in twenty-four hours have absorbed eight thousand six
hundred and forty inches, equal in weight to fourteen
inches of water and two fifths, which according to
Dr. Kirwan’s estimate is between seven and eight
ounces. But the quantity of matter insensibly perspired
in that time is so much greater, that no calculation can
be made. Here is one mode of determining the quantity
of oxygen inspired totally impracticable in the human
body, though quite easy and practicable in the
case of mercury. The other mode of determining it
by the expulsion of oxygen from the blood is equally
impracticable. Dr. Girtanner indeed has expelled oxygen
from flesh; but we know not in what proportion,
nor can we determine whence it came. With regard to
this last, indeed, there are two sources allowed by Drs.
Beddoes and Girtanner themselves; viz. the absorption
of oxygen by the lungs, and the quantity taken in with
the aliment. A third source was also manifest from Dr.
Girtanner’s experiments; viz. absorption from the atmosphere;
for, by exposure to the atmosphere, flesh,
which had once parted with its oxygen, became again
impregnated with it. In this case therefore we must
acknowledge that the uncertainty of the absorption by
the lungs must be extremely great. A certain quantity
of oxygen is undoubtedly thrown out in fixed air. How
are we to determine this quantity? Certainly not by the
first reverie that happens to occupy our imagination.
It is a problem, the solution of which must be attended
with the utmost difficulty. We must know, in the first
place, how much oxygen was contained in the air inspired.
In the second place we must know the quantity of
fixed air expired. In the third place we must exactly
know the proportion of oxygen contained in the fixed
air thrown out by the breath. In the fourth place we
must determine whether, by the conversion of oxygen
into fixed air, any change is made in its bulk. For, if
this shall be found to be the case, we should be led to
suppose an absorption or augmentation of air when no
such thing took place. This point therefore ought to
be determined with the utmost accuracy. In the fifth
place we must exactly know how much azote, septon,
phlogisticated air is contained in the atmosphere inspired,
and likewise in that expired. In the sixth place, we
must be assured that there are no other fluids in the atmosphere
capable of being absorbed by the lungs, excepting
oxygen and azote. Whether there are any
others or not, hath not been determined. From an
expression of Dr. Fordyce, he would seem to be skeptical
on the subject. “The atmosphere (says he) is found
to consist of various vapours, of which air, or, as it
has been called, pure air, or respirable air, (oxygen air)
forms at present about a fourth. Gas (probably fixed
air) forms some part;72 but the greatest part consists
of one or more vapours, which, without any positive
quality, but from that indolence which makes mankind
in their researches attempt to find a resting place, have
been considered by many chemists as one individual species,
under the names of phlogisticated air,” &c. In the seventh
place we ought to know what quantity of pure oxygen,
unconverted into fixed air, or whether any such, is
thrown out by the breath. That a quantity of this
kind of air is really thrown out, is probable, because we
can blow up a fire with our breath, and by a blow-pipe
excite a most intense heat, capable of melting the most
refractory metals, platina excepted. It is true that the
eolipile, by the mere conversion of water into steam, will
blow up a fire also; though, if the access of external air
be denied, the blast of the eolipile will put the fire out.
Probably the breath would do the same; but even this
cannot be accounted a decisive proof of the oxygen being
totally exhausted; for the moist vapour with which
the breath abounds may extinguish the fire, even though
some small quantity of oxygen should remain in it. It
is not, however, our business at present to enter minutely
into such discussions. From what has been already said,
it is evident, that the absorption of oxygen by the blood,
instead of being indubitably established, is of all things
the most uncertain; the requisites for determining it being
absolutely beyond the investigation of any person,
however accurate. We may indeed, with great labour
and trouble, determine that some part of the air is absorbed
in breathing; but what that part is, we are unable
to discover from any chemical investigation. The
opinion of the simplicity of metals, and their being reduced
to a calx by the adhesion of oxygen, has been
so implicitly, and in a manner universally, received, that
it has given a new turn to physiology, so that, by a kind
of analogical reasoning, the human body has been reduced
to a mere chemical apparatus, the operations of
which may be calculated as we can do the event of experiments
in a laboratory. But, after a very long and
tedious contest, Dr. Priestley seems at last to have overthrown
this doctrine of oxygenation, even in the inanimate
parts of the creation; so that we can much less
apply it to the doctrines of life and animation. His
experiments are published in the third number of
the Medical Repository, volume II, and fully demonstrate,
that, though mercury absorbs oxygen during
calcination, this is not the case with all metals;
that in many cases the oxygen will unite with other
substances in preference to the metal, which last is nevertheless
reduced to a calx as though it had united with
the oxygen; that in many cases the addition of weight
gained by the calx is owing to mere water, &c. He
has likewise shown that phlogisticated air (azote) is not
a simple substance, as has been taught by the new chemists,
but consists, as well as fixed air, of an union of
oxygen with carbon, or at least with the black matter
of burnt bones, with which he made the experiment.
These aerial fluids therefore being so easily convertible
into one another, and the uncertainty of the changes in
bulk which may occur in consequence of these conversions
so great, it is impossible to say whether a portion
of the atmosphere in substance, i. e. both oxygen and
azote, is absorbed, as physicians formerly supposed; or
whether a portion of oxygen air alone be absorbed, as Dr.
Beddoes supposes; or whether only the elastic principle
itself is absorbed, and the diminution in bulk made in
consequence of the conversion of oxygen into fixed air;
I say, these matters depend on circumstances so much
beyond the reach of our senses, that if we come to any
probable conclusion upon the subject, it must be by
analogical reasoning from other known facts, not from
experiments made directly upon the living body; which,
in their own nature, must, always be extremely vague and
uncertain.
5. That, during the circulation, the blood charges
itself with carbonic hydrogen air, is an assertion which
cannot be easily admitted. It has already been observed,
that, by the air-pump, venous blood does not appear to
contain any elastic fluid whatever; and it is also certain,
that animals cannot bear any quantity of air injected
into their veins. Dr. Girtanner himself tried several
kinds, and all of them proved fatal. Having injected a
considerable quantity of oxygen air into the jugular vein of
a dog, the animal raised most terrible outcries, breathed
very quickly, and with the utmost difficulty; by little
and little his limbs became stiff, he fell asleep, and died
in less than three minutes. On injecting into the vein
of another dog a small quantity of phlogisticated air, the
animal died in twenty seconds. With carbonic acid gas
(fixed air) a third dog died in a quarter of an hour. A
fourth was killed in six minutes by nitrous air.73 From
these experiments, had no others ever been made on the
subject, it seems very probable, that no species of air can
be safely admitted into the blood in its elastic state. If
any such therefore should naturally be produced in the
body, it must either be instantly thrown out, or disease
must ensue. Such objections to the Doctor’s theory are
so natural, that we might have thought he would have
foreseen and provided against them. Instead of this he
grounds the whole upon such slender evidence as could
not be admitted in the most trifling matter. “An incision
(says he) was made in the jugular vein of a sheep,
and the blood which came from it was received into a
bottle filled with nitrous air. When the bottle was
half filled, it was closed. The blood coagulated immediately,
and a separation of a great quantity of blackish
serum took place. The day after, on opening the
bottle, a very strong smell of nitrous ether (dulcified
spirit of nitre) was perceived, the nitrous air having
been changed in part into nitrous ether by the carbonic
hydrogen gas of the blood. This experiment
proves, beyond a doubt, that the venous blood contains
carbonic hydrogen air; and that this air is not very intimately
mixed with it, but may be expelled with the
greatest ease.”
On reading the Doctor’s account of this experiment;
it must be very obvious, that, however decidedly he may
be of opinion that it proves beyond a doubt the existence
of hydrogen air in the venous blood, yet there is not one
solid reason; from what he says, for supposing any such
thing. How can any man determine from the mere
smell of sheep’s blood taken out of the body of the animal,
and mixed with a poisonous vapour, what is the composition
of human blood in the living body? In the case
of any substance suspected to contain elastic air, the air-pump
will always afford an experimentum crucis. But we
know that venous blood does not yield any elastic vapour
by the pump: if instead of blood, however; we should
fill a portion of vein with beer, cyder, or other fermented
liquor, it would instantly discover, by its swelling up,
that it really contained air in an elastic state. If then
from the tumefaction of the vein when filled with fermented
liquor we conclude that the latter contains fixed
air, why should we not, from the non-tumefaction of it
when filled with blood, conclude that the vital fluid
contains no air? If Dr. Girtanner was so well assured
that the venous blood contains hydrogen air, he ought to
have expelled some of it from a portion of the blood,
noted the difference between the blood which had lost
its air, and that which had not, and then, by adding the
air to it again, restored the blood to its former state.
Nothing less then recomposition can prove the truth of a
chemical analysis; as division can only be proved by
multiplication, or multiplication by division.
From all that has been said, we may fairly conclude,
that no proof can be brought sufficient to prove the existence
either of oxygen air or any other species of aerial
fluid, in its elastic state, in the blood. Neither can we
prove that any part of the condensable part of oxygen
air is received by the breath in the lungs. It is, however,
probable that this condensable part may be received
into the stomach with our food; that having passed
through the various channels of circulation, and arrived
at last at the surface, it there resumes its aerial nature by
combining with the superfluous heat of the body, and is
evaporated through the pores of the skin by insensible
perspiration. The aerial vapour which passes off by these
pores indeed has been discovered to partake of the nature
of fixed air; but we know that this species of gas always
contains the basis of oxygen, being indeed composed of it;
and whether the oxygen be taken into the body in its
pure state or not, the result would undoubtedly be the
same; for an union would be formed between it and
the carbonic particles to be thrown off from the body.
But thus we can never suppose the basis of oxygen or
any other air to be a permanent part of the composition
of our bodies; nor can the quantity of it be augmented
by breathing any kind of air. The readiest way to increase
the quantity seems to be by drinking fermented
liquors. Thus, if the body is too hot, the superfluous
heat will have a proper subject to act upon, viz. the condensable
part of the fixed air; and hence we may perhaps
account for the very grateful and cooling sensation
produced by drinking these liquors in some diseases.
With respect to the existence of carbon, charcoal or hydrogen
in the blood, it is probable that it exists in equal
quantity at all times, being indeed the fundamental material
of the whole body, and probably only a modification
of that dust from whence man was originally taken.74
When the blood therefore grows very black, when the
teeth are covered with a black sordes, the hands become
foul, &c. we may say, indeed we too surely feel, that, in
such cases, there is a propensity in the body to return to
its original state of dissolution; but there is not one solid
reason for supposing the proportion of its materials to be
varied; that there is a collection of oxygen in one part,
hydrogen in another, or in short that nature can admit of
any such disproportion taking place.
6. We must now consider Dr. Girtanner’s account
of the origin of animal heat, which is, that, “during
the distribution of the oxygen through the system,
the heat which was united with this oxygen escapes;
hence the animal heat;” and, “that the great capacity
of the arterial blood for heat is owing to the oxygen
with which it is united in the lungs.”—This leads us
to consider in a more particular manner the doctrine of
heat, a subject hitherto much less investigated than the
importance of the subject requires. What little we do
know of this matter seems to be almost entirely owing to
Dr. Black, who hath discovered some very remarkable
phenomena unknown to former philosophers. His discovery
here, as in that of fixed air, was accidental. Making
experiments on the water of different temperatures,
he found that the mixture would always be an arithmetical
mean betwixt the two quantities mixed. Thus,
on mixing water at 50 degrees with an equal quantity
at 100, the temperature of the mixture would be 75
degrees; but if instead of using water only he took snow
or ice for one of the quantities, the mixture was no longer
an arithmetical mean betwixt the two temperatures,
but greatly below it; so that a quantity of heat seemed
to be totally lost and in a manner annihilated. His attention
was engaged by this unexpected phenomenon, and,
prosecuting his experiments, he found that, when water
was converted into ice, it really became warmer than it
was before; and, by keeping the fluid perfectly still
during the time that cold was applied, he was able to
cool it to 27 degrees of Fahrenheit’s thermometer, which
is five degrees below the freezing point; but on shaking
this water so cooled, it was instantly converted into
ice, and the thermometer rose to 32. On reversing
the experiment he found that mere fluidity in water is
not sufficient to melt ice. A considerable degree of
heat is necessary; and even when this is previously given
to the water, the whole becomes as cold as ice by
the time that the ice is melted. The result of his experiments
in short was this: Water, when frozen, absorbs
an hundred and thirty-five degrees of heat before
its fluidity can be restored: that is, supposing a pound
of ice at the temperature of 32 to be mixed with a
pound of water at the temperature of 32, by adding 135
degrees, so that the temperature of the water is augmented
to 167, the ice will indeed be melted, but the temperature
of the whole quantity of liquid will be reduced
to 32. In this case therefore the heat manifestly assumes
two different modes of action: one in which it acts internally
upon the substance of the body, without being
sensible to the touch, while in its other state it hath no
effect upon the internal parts, but affects bodies on the
outside. The former state therefore the Doctor distinguished
by the name of latent, the latter by that of sensible
heat.
The same theory was applied to explain the doctrine
of evaporation, and that in the most decisive and satisfactory
manner. The Doctor found, that, in the
distillation of water, much more heat was communicated
to that in the worm-tub of the still, than could
be supposed necessary to raise the water distilled to 212
degrees, which is the utmost that water can bear. In
prosecuting the experiment he found the quantity of
heat absorbed by the water, when raised into vapour,
truly surprising; no less than a thousand degrees; an
heat more than sufficient to have made the whole quantity
of fluid that came over red hot. Some objections,
however, were made to this theory, even by the
Doctor’s friends. Mr. Watt, particularly, though he
could not deny the theory derived from Dr. Black’s
experiments, yet suggested one, which, had it proved
successful, would have overthrown the whole. It was
this: Let water be distilled in vacuo, where it boils with
a heat of 97 degrees, and the operation must be carried
on with much less fuel, and with much greater ease, than
in the common mode. It was said that, in this experiment,
Dr. Black was equally concerned with Mr. Watt;
but, in a personal conversation with the Doctor himself,
he assured me that he had no farther concern than foretelling
that the experiment would not succeed, which it
seems did not. The event was as follows: Mr. Watt,
determining at all events to try the experiment, caused
to be made a copper retort and receiver, joined together
in one piece. In the receiver he pierced a small hole,
and, heating both retort and receiver, plunged the latter
into cold water. The consequence was, that a considerable
quantity of water entered the vessel, and was easily
poured back into the retort, as a subject for distillation.
A fire being now applied, the water was soon raised into
steam, which filled both retort and receiver, and in a
great measure expelled the external air. The small orifice
in the receiver being now closed, and the receiver
itself plunged into cold water, the distillation went on
in vacuo; for, as soon as any of the steam was condensed,
the space which it had occupied (according to Dr.
Black one thousand and sixty-six times more than the original
water) was become absolutely empty, and more
steam, rarefied, not by any quantity of sensible heat,
but merely by that which it contained in a latent state,
would occupy the place of the former. The event of
the experiment showed the truth of Dr. Black’s theory.
The water boiled, and steam was raised as well as if
access had been given to the air; but with this difference,
that the upper part of the distilling vessel was never heated
above what the hand could easily bear. With the
water in the cooler it was quite otherwise. It became
hot as usual, and, by the quantity of heat it received,
plainly demonstrated that the vapour, though destitute
of most of its sensible heat, yet contained an immense
quantity in a latent state. The saving of fuel therefore
in the practice of distillation, which was Mr. Watt’s object
in making the experiment, was quite trifling, and
not equal to the trouble of filling the retort with liquid.
The doctrine of latent heat thus established, furnished
a solution of many phenomena which could not formerly
be explained in a satisfactory manner. Thus the
melting of all kinds of substances was found to be owing
to an absorption of heat, while their condensation was attended
with the contrary. Fluidity in all cases was explained
on the same principle; and the more heat that
was absorbed, the more fluid the matter became. Thus
water, when in a condensed or solid state, absorbs 135
degrees of heat before it becomes fluid. A thousand degrees
more convert it into vapour, and at last, by passing
through the intense heat of a glass-house furnace, it
is converted into a brilliant flame, and augments the
heat of the furnace to a great degree. Hence the practice
in glass-houses of throwing water into the ash-hole,
the vapour of which, by passing through the burning
fuel, makes the furnace much hotter than it was. In a
similar manner were explained the phenomena of crystallization,
the ductility of metals, the heat produced by
hammering them, and the hardness produced by the operation,
as well as the operation of annealing, &c. One
other phenomenon, a very curious one, shall be noticed,
on account of its being connected with the subject of this
treatise. It is this: Let a small vessel filled with vitriolic
ether be put into a larger one of water, and both
included in the receiver of an air-pump. On exhausting
the air, the ether boils, and is converted into vapour,
while the water freezes. This shows that heat
does not always act equally upon surrounding bodies, but
has a tendency to enter some in preference to others;
and from other experiments it appears, that this property
has a considerable connexion with the density of the
bodies concerned.
Thus one step was gained, and it was universally admitted
that heat, in some cases, entered bodies, and in
others was thrown out of them; but now the question
arose, What is heat; and by what laws is it regulated,
or from what source is it derived? Here Dr. Black
himself was at a loss; for, as he supposed cold to be a
mere non-entity, and only to consist in a comparatively
smaller degree of heat, some phenomena occurred which
would not easily admit of solution upon such an hypothesis.
With these Dr. Black did not meddle much,
but others were bolder. Dr. Irving, Professor of Chemistry
at Glasgow, undertook to explain the whole mystery
of latent heat upon the single principle of attraction.
One of the most puzzling phenomena in the way of Dr.
Black’s theory had been, that in some cases heat and cold
seemed to repel each other, and a very remarkable instance
of this was, that, in the morning, a little before
sunrise, when the rays of light pass through the atmosphere,
a little above the surface of the earth, the air then
becomes manifestly colder than even at midnight. Dr.
Irving’s explanation of this was, that the sun’s rays
attracted heat from the atmosphere, and thus rendered it
colder. Such at least was the explanation given in an
inaugural dissertation by Dr. Cleghorn, one of Dr. Irving’s
scholars; for the Doctor himself delivered his
opinions only to them. In other cases he supposed that
different substances had different capacities for receiving
heat; and, of consequence, should the form, or rather
the internal constitution, of the body be changed, the capacity
of it for receiving heat must also be changed; and as
an attraction subsists, or is supposed to subsist, between
heat and all other substances, it is plain that while this
attraction subsists, if the capacity of any substance for
receiving heat be augmented, it will imbibe much more
than it would have done had its former constitution remained.
Thus water in its liquid state contains a certain
quantity of heat; we may therefore say that water
has a capacity for receiving heat equal to one to ten, or
what we please. Vapour has a capacity for containing
heat ten times greater than water. Water therefore,
when converted into vapour, will imbibe ten times the
quantity of heat that the water contains; and, again, on
being re-converted into water, the capacity becoming
what it was before, the superfluous quantity must be
thrown out, as in Dr. Black’s experiments. In like
manner, when a metal is melted by the fire, the capacity
of it for receiving heat is changed: of consequence a
great quantity is imbibed, and again expelled by the
change of capacity which takes place on its becoming
solid; and thus, from the change of capacity, in different
substances, every phenomenon was solved.
This doctrine of capacities did not give general satisfaction.
Dr. Black himself said of it, that it was neither
probable nor ingenious;75 notwithstanding which, it
continued to be received, and even very generally adopted.
Dr. Crawford, so well known for his writings on
this subject, has adopted the idea, and Dr. Girtanner, in
the passage above quoted from him, appears to be of the
same opinion. The doctrine, however, had several opponents,
among whom were the Monthly Reviewers.
In their account of Nicholson’s First Principles of Chemistry,
they express themselves in the following manner:
“We only wish, that, in the doctrine of heat, he had
avoided, which he might easily have done, Dr. Crawford’s
idea of bodies having different capacities for
heat. In the melting of ice, for instance, a quantity
of heat is absorbed, without any increase of the
temperature, that is, without making the water sensibly
warmer than the ice before its liquefaction; which
is said to be owing to the water having a greater capacity
for heat, or being able to hold more of it, than
the ice; and, in like manner, when converted into
vapour, its capacity is further increased, or it can hold
more still. This appears to us a very unchemical, and
a very inadequate idea of the matter: for, admitting
water to have a greater capacity than ice, how is the
change from one state to the other to be effected?
Can the properties which a body is found to possess,
after a change has taken place, be assigned as a cause
of the change itself? Or will it be said, that the heat
first enlarges the capacity, and then hides itself in that
capacity so enlarged? We should think it much better
to say, consonantly with the phenomena of other
combinations in chemistry, that a certain quantity of
heat, uniting with the ice, first liquefies it, as a certain
quantity of acid only neutralizes an alkali; that if
any surplus quantity must be introduced, that surplus,
remaining free and uncombined, must act and be sensible
as heat in the one case, and acid other; and that
different bodies require different quantities of heat or
acid to be combined with them, for producing the
changes in question.”76
Thus the Reviewers, as well as others, reasoned a priori,
and several facts were adduced to prove that no such
changes in capacity could take place. But however
strong the arguments adduced, or however plain the experiments
might be, little or no notice was taken of them,
and the enlargement or diminution of capacities has been
repeated, seemingly by rote, from one author to another,
without the least inquiry or investigation. Dr. Girtanner
indeed says that “the oxygen united with the arterial
blood in the lungs” is the cause of the great capacity
of the arterial blood for heat. But this is assigning a
very doubtful cause for a very doubtful effect. He
ought to have proved in the first place that arterial blood
really has this capacity; for its being hotter than the
blood of the veins, only shews that it parts with more
heat to surrounding bodies than venous blood does;
which is a proof that it contains less heat, if there be any
difference, than that of the veins. But the truth is, that
the capacity for containing heat depends neither on the
oxygenation nor hydrogenation of a fluid, but upon its
density. The more fluid and the more easily expansible
into vapour that any substance is, the greater quantity
of heat it is capable of containing, and vice versa.
This has been fully ascertained by Mr. William Jones,
an English clergyman, whose observations on the generally
received system of philosophy contain many particulars
worthy of attention. From his experiments it appears
that a piece of red-hot iron, thrown into water,
imparts much less sensible heat to it, and is itself much
more effectually quenched, than by throwing it into an
equal quantity of quick-silver of the same temperature
with the water. As the quick-silver therefore becomes
much hotter to the touch than water does upon throwing
a piece of red-hot iron into it, and as the iron itself is
much more imperfectly quenched by the metal than by
the water, it follows that the latter is capable of containing
much more heat than the former. But such experiments
are not applicable to the blood. Though that of the
arteries may be somewhat hotter than the venous blood,
yet the reason is obvious. The heat is communicated
directly to the arterial blood in the lungs; but during
the circulation a part of it evaporates, and the farther
distant any part is from the lungs, the more cool will
the vital fluid be, without regard to any alteration of
capacity, which indeed never can be shown to exist.
But the most decisive experiments against any supposed
alteration in the capacities of bodies for containing
heat are those lately tried by Count Rumford, and
related in the Philosophical Transactions for 1798. His
attention to this subject was engaged by observing the
great degree of heat acquired by a brass gun during the
time of boring it,77 and still more by the intense heat
(much greater than that of boiling water) of the metallic
chips separated from it by the borer. From a consideration
of these things he was naturally led to the following
inquiries. “Whence comes the heat actually
produced in this mechanical operation? Is it furnished
by the metallic chips which are separated by the
borer from the solid mass of metal? If this were the
case, then, according to the modern doctrine of caloric,
the capacity for heat of the parts of the metal so reduced
to chips, ought not only to be changed, but the
change undergone by them be sufficiently great to account
for all the heat produced. But no such change
had taken place; for I found, that by taking equal
quantities by weight of these chips, and of thin slips of
the same block of metal, separated by means of a fine
saw, and putting them at the same temperature, that
of boiling water, and putting them into equal quantities
of cold water (that is to say, at 59 1/2 of Fahrenheit)
the portion of water into which the chips were put,
was not, to all appearance, heated either less or more
than the other portion in which the chips were put.”
From this experiment, several times repeated with the
same result, Count Rumford inferred, that the heat
could not possibly have been furnished at the expense of
the latent heat of the metallic chips. He then proceeded
to ascertain “how much heat was actually generated
by friction, when a blunt steel borer being so forcibly
shoved (by means of a strong screw) against the bottom
of the bore of the cylinder, [of the machine in use]
that the pressure against it was equal to the weight of
about ten thousand lb. avoirdupois, the cylinder
being turned round on its axis (by the power of horses)
at the rate of about thirty-two times in a minute.”
In this experiment the metallic dust or scaly matter detached
from the cylinder by the borer weighed only 837
grains troy; but, says the author, “Is it possible that
the very considerable quantity of heat produced in this
experiment (a quantity which actually raised the
temperature of above 113 lb. of gun-metal at least 70
degrees of Fahrenheit’s thermometer, and which of
course would have been capable of melting 6 1/2 lbs. of
ice, or making near five pounds of ice-cold water to
boil) could have been furnished by so inconsiderable a
quantity of metallic dust, and this merely in consequence
of a change of its capacity for heat? As the
weight of this metallic dust (837 grains troy) amounted
to no more than one 948th part of that of the
cylinder, it must have lost no less than 948 degrees of
heat to have been able to raise the temperature of the
cylinder one degree; and consequently it must have
given off more than sixty-six thousand, three hundred and
sixty degrees of heat to have produced the effects which
were actually found to have been produced in this
experiment.”
It was next considered whether the air did not contribute
to the generation of this heat; and our author
determined that this could not be the case; because the
quantity of heat generated was not sensibly diminished
when the free access of air was prevented. From another
experiment it appeared that the generation of the
heat was neither prevented nor retarded by keeping the
apparatus immersed in water. Here the friction generated
so much heat, that in one hour the temperature of
the water surrounding the cylinder was raised from 60 to
107 degrees of Fahrenheit. In half an hour more it was
raised to 142; at the end of two hours to 178; at two
hours 20 minutes to 200; and in two hours and a half
it boiled.78 On the whole, Count Rumford concludes,
that “the quantity of heat, produced equably by the
friction of the blunt borer against the bottom of the
hollow metallic cylinder, was greater than that produced
equably in the combustion of nine wax candles, each
three quarters of an inch diameter, all burning at the
same time with a clear, bright flame.” From all these
experiments, however, our author does not draw any certain
conclusion. “What is heat? (says he.) Is there
any such thing as an igneous fluid? Is there any
thing that can with propriety be called caloric? The
heat produced, in the author’s experiments, by the
friction of two metallic surfaces, was not furnished by
small particles of metal, detached from the larger solid
on their being rubbed together. It was not supplied
by the air, because the machinery in three experiments
was kept under water, and the access of atmospherical
air completely prevented. It was not furnished by the
water which surrounded the machinery, because this
water was continually receiving heat from the machinery
and could not at the same time be giving to and
receiving heat from the same body; and because
there was no chemical decomposition of any part of
this water.” At last he observes, that the source of
this heat, whatever it is, must evidently be inexhaustible,
adding, that “any thing, which any insulated body,
or system of bodies, can continue to furnish without limitation,
cannot possibly be a material substance; and
it appears to me to be extremely difficult, if not quite
impossible, to form any distinct idea of any thing capable
of being excited and communicated, in the manner
the heat was excited and communicated in these
experiments, except it be MOTION.”
On this last paragraph, however, it is obvious to remark,
that the whole force of the argument rests upon
an insinuation, that the cylinder and borer were insulated,
or cut off from all communication with any other material
substance. Had this been the case, then no doubt
it would follow that an endless supply of any thing material
could not be furnished by them; but if, as Dr.
Boerhaave and many other learned and intelligent persons
have supposed, fire be an element universally present,
and which becomes sensible to the touch only in
consequence of a particular mode of action, it will follow,
that no substance in nature can be insulated with
respect to it; but, in whatever place, and for whatever
length of time, any substance shall be affected in such a
manner as to agitate this fluid, there we shall perceive a
production of heat without limitation, even though heat
itself be no more than the action of a fluid essentially
material, though invisible to us.
Considerations of this kind occurred long ago to the
writer of this treatise, when by the nature of his employment
it was necessary for him to speculate upon these
subjects. It could not then but appear to him that the
theory of Dr. Black was far superior to any that had
been published. The opinion of those who supposed
fire to consist in the vibratory motion of the particles of
solid bodies, seemed altogether untenable. It is impossible
to explain the phenomena of heat upon ordinary
mechanical principles, because, with respect to all terrestrial
substances, heat constantly appears as an agent,
while they are merely passive; and no man can explain
the nature of a cause from its effect. Thus one of the
most obvious effects of heat is expansion, or enlargement
of bulk, in such bodies as are heated. But if from this
fact we infer that the parts of elementary fire are repulsive
of one another, our reasoning is certainly erroneous.
In like manner, when we are not sensible of heat, we
are not authorised to conclude that it is not present;
for Dr. Black has demonstrated that it may be present
in very great quantity, though indiscoverable either by
our senses or by a thermometer.
But, with regard to the theory published by Dr.
Black himself, it is evident that, though one part of it
rests on the solid basis of experiment, the other is founded
entirely upon hypothesis, and that too an hypothesis
which cannot admit of being proved by any experiment,
viz. that cold is a mere negative, and hath no real
existence in nature. Among many phenomena which
militate against this opinion, the following experiment
of M. Geoffrey seems to be the most remarkable.
He took a small bason filled with water, and set
it on a support in the middle of a large tub of water,
in such a manner that the temperature of the water in
the tub might communicate itself to that in the bason.
This being ascertained by a thermometer placed in the
bason, he threw a quantity of burning coals into the
tub. The effect of this, on the supposition that cold is
a mere privation of heat, ought to have been, that the
heat of the coals, communicated to the water in the
large tub, would in a short time pervade the small bason,
and affect the thermometer there. The latter
would therefore rise; but instead of this it fell several
degrees before it began to rise; for which it doth not
appear that any other reason can be assigned than that
the cold is partly repelled by the heat of the coals,
and therefore, entering into the small bason of water, it
causes the thermometer to sink previous to its rising.
To the same purpose we may urge the phenomenon
already taken notice of, viz. that the sun’s rays,
when passing at some distance above the surface of the
earth, cool the lower part of the atmosphere. The natural
solution is, that the heat of the sun partly repels
the cold downwards; and as for the doctrine of attracting
heat from the atmosphere, Count Rumford has shown
that this does not happen in a case where we might with
much more probability expect it; not to mention the
violence done to the common perceptions of mankind
by supposing the sun’s rays, which are most evidently
the source of heat, to have any occasion to attract heat
from the atmosphere or any thing else.
Lastly, with regard to the capacities of bodies for containing
heat, the doctrine appears to involve a radical
error, of such enormous magnitude, that it is impossible
to make any thing of it. This is no less than confounding
the heat which flows out from bodies with
that which they contain as an essential part of their
composition, and which they cannot emit without being
changed into some other form. Thus the capacity of
aqueous vapour for containing heat, according to Dr.
Black, is 1000 degrees; yet without decomposing the
vapour it would have been impossible to have known
this; for vapour is often extremely cold to the touch,
and a thermometer immersed in it will sink greatly.
In short, all that we can know about the capacity of
bodies for retaining heat is, that they either continue to
absorb it, or we may continue to force it into them, till
they be reduced to vapour. It is doubtful whether
they can receive more; for from the experiment with
Papin’s digester, formerly mentioned, it appears that the
additional quantity of heat, which the water was made
to receive, very quickly left it as soon as the steam had
room to expand.
But, to come to a conclusion upon this subject: If
we will investigate the nature of heat, we must do it as
in other cases, viz. by making the igneous fluid, caloric,
or what we please to call it, the object of our senses; for
we cannot reason fairly, or indeed come to any rational
conclusion at all, by doing otherwise. In this investigation
it is necessary to attend to the particulars mentioned
by Count Rumford. The fluid must be omnipresent
in its nature, infinite in its quantity, and equable,
uniform and incessant in its action; as far as these
epithets can be applied to any material being. There
are only two fluids which we know that can answer to
these characteristics. The one is the light of the sun,
which pervades all the celestial spaces; the other the
electric fluid, which penetrates every terrestrial substance.
Both of these produce heat, unlimited in quantity, as
well as in duration, provided their action be continually
kept up. The mode in which both produce heat is exactly
the same, viz. by converging into a focus; and
the greater the quantity, the greater is the heat, and that
without any limitation either as to intensity or duration.
With regard to the solar rays, it has long been known
that by concentration they would produce heat; nevertheless
it was unaccountably doubted whether the rays
themselves were the matter of heat. One objection to
this was, that on the tops of high mountains the air is
exceedingly cold, though the sun shines very bright.
But this objection was founded upon an erroneous notion
that, wherever the matter of heat exists, there we must
feel it; which doth not follow any more than that
wherever air exists there we must feel a wind blowing
upon us. Wind is air in motion, and heat is a more
subtile fluid in motion. One demonstration of this is,
that, on the tops of the highest mountains, a burning
lens or mirror will set fire to combustible bodies as readily
as in the vallies at the foot of them. Neither has
heat, properly so called, anything to do with air. The
focus of a burning-glass will heat bodies in vacuo as well
as in the open air; and Sir Isaac Newton has observed,
that if a thermometer be included in the vacuum of an
air-pump, it will acquire the temperature of the room
nearly in the same time that another will when included
in a similar glass without any exhaustion.
The science of electricity is but of late date; and
most violent and hypothetical disputes have taken
place concerning the nature of the fluid. Its luminous
and burning properties naturally led a number of people
to suppose that it was elementary fire; but this was opposed
by others with as much violence as if there had
been something criminal in the supposition. The opposition,
however, was founded upon the same error with
that about the solar light. It was imagined that wherever
elementary fire existed, there heat must be felt; and
it was especially urged, that electricity, though it produced
light, did not produce any heat, except when it
exploded with such violence as to penetrate the internal
substance of bodies, agitating their particles, and by this
agitation producing heat. It has now, however, been
found, that the electric aura, as it is called, when made
to converge in great quantity to the point of a needle,
will heat it to such a degree as to set fire to gun-powder.
This shows that heat is occasioned by the convergence
of this fluid to a focus, and to its divergence from
it. In the focal point, heat will always take place.
From the experiments of Hauksbee, Beccaria and Priestley,
it likewise appears, that electricity will render transparent
the most opaque bodies, such as sealing-wax,
pitch, &c. which even the most intense light of the sun
cannot do. As to the intensity of the heat produced
by it, experiments have shown, that it cannot be exceeded
even by that of the most powerful mirror. Globules
of gold have been vitrified, platina melted, and
the most infusible substances reduced to glass, by means
of the electric shock. From so many evidences, therefore,
it appears to me impossible to conclude otherwise
than that the light of the sun and the electric fluid are
the same thing; and, according to the different modes
in which they act, they produce the phenomena of heat
and light in all their varieties, besides a multitude of
other effects of which we cannot have any perception.
We may indeed, if we please, suppose that some other
thing exists which is heat itself, and that the light or
electric fluid sets in motion, attracts, repels, or acts
otherwise upon this unknown something; just as it
comes into our heads to fabricate our system. But, until
our senses can discover in some way or other this hidden
substance, reason will always suggest that it has no existence.
We may say that without such a supposition we
cannot solve the phenomena of heat. But do we ever
expect to solve these phenomena; or do we know all
that the solar light and electric fluid can perform? If
we do not know what they can do, neither do we know
what they cannot; and the invention of other fluids
must be accounted not only chimerical but useless.
But, to be more particular: on the subject of heat
people have embarrassed themselves more with philosophical
reveries than by any real difficulty, and rendered
the matter more obscure than nature has made it. We
have already observed, that by the convergence of light,
or of electricity, heat is always produced. Here we can
see the mode in which the fluid acts, viz. first by converging,
and then diverging. When the light falls upon
a solid body, it is evident, that if it be allowed to flow
out as easily as it flows in, no internal agitation of the
parts, or of any fluid contained in them, can take place.
Transparent bodies therefore are never heated. Again,
if the light be not allowed to enter the substance of a
body, but is entirely reflected, the body cannot be heated;
and hence it is very difficult to melt a polished
metal even by a strong burning-glass. M. Macquer’s
burning mirror, which vitrified flints, could not melt
silver. But, when the light falls upon a body capable
of allowing it to enter its substance, at the same time
that it cannot get out without difficulty, it is plain that
the force of the fluid will be exerted in order to overcome
that difficulty; the body will be expanded in all
directions; the fluid will be thrown out in the same
manner, and the more that the internal action of the
light prevails over that power by which the parts of the
body cohere, the more will the phenomena of heat be
perceptible.
Again, let us suppose that the etherial fluid enters the
substance of any body capable of being dilated to a great
degree, it is equally plain that the action of the fluid
must for some time be directed only upon the internal
parts, and consequently will be imperceptible on the
outside. This then is called latent heat; and where the
pressure on the outside balances that on the inside no
heat will be perceptible to the touch. But by whatever
means this balance is broken, heat will instantly be perceptible;
and experiments show that the balance may
be broken either by an increase of cold or heat. Thus,
in the case of water, the internal pressure remains equal
to the external, until the fluid is cooled to a few degrees
below 32. The balance is then broken, and the internal
action prevails; a quantity of what is called sensible
heat escapes, and the water is converted into ice. Again,
at the temperature of 32, little or none of the water evaporates;
but by the addition of heat, by which the internal
action of the subtile fluid we speak of becomes
greater than the external, the water is converted into
vapour; and it is remarkable that the same effect takes
place on greatly augmenting the degree of cold; for the
evaporation from ice, even in frosty weather, is found to
be very considerable.
On the whole, from innumerable experiments it appears,
that there exists in nature a certain invisible fluid,
by the action of which, when diverging from a centre,
heat is produced in the central point. By a certain other
power this diverging force is limited, so that in some
cases it is not perceptible beyond the surface of the body
in which it acts, and then it is called latent heat. In
other cases it is perceptible in a certain degree, and the
degree in which it is perceptible hath been called the
temperature or sensible heat of the body. On mixing different
substances together it is found, that very often
the proportions between the external and internal actions
are varied. This has been already observed, when giving
an account of Dr. Black’s discovery of latent heat,
viz. that when snow and warm water are mixed together
the temperature of the mixture differs very considerably
from the arithmetical mean between the temperatures of
the two substances employed. Dr. Crawford prosecuted
the experiment further, and found that there were few
substances which, on being mixed, did not shew a temperature
different from that of the arithmetical mean between
the temperatures of the two originally employed.
This difference he unfortunately used as the foundation of
a rule for determining the capacities of different substances
for containing heat, and upon this erroneous principle
has raised a superstructure, which upon no occasion
can be of service to science, but must always produce
obscurity and confusion wherever it is introduced.
With regard to the power which sets bounds to the
expansion of the fluid acting as heat, it is natural to
think that it can be no other than the same fluid acting
in a contrary direction, or from a circumference towards
a centre; and thus we shall always find that the same
fluid, by limiting its own operations, may produce those
phenomena which have been hitherto deemed so difficult
of explanation. In what manner this limitation is
in all cases effected, or indeed in any case, we cannot
pretend to explain. It is sufficient to observe, that
wherever there is a perpetual efflux of any thing, there
must be also a perpetual influx at the same time, and in
proportion to the one the other will be. These two are
directly contrary to one another, and, as we suppose the
fluid to be universal, it is evident, that if any part of it
be put in motion in a particular direction, the rest will
press towards that part where the motion is, in order to
keep up the equilibrium. Hence we may easily account
for the heat produced by percussion or by friction. By
hammering a piece of iron, as Dr. Black justly observes,
the fluid is forced out from between the parts of the
metal. The emission of this fluid in all directions is
heat itself; and no sooner is one quantity thrown out than
another supplies its place with great rapidity, and so on,
until the pressure of the rest in some way or other counteracts
the emission of any more, and the heat ceases.
Just so with friction. The heat produced by it is always
in proportion to the pressure employed. By this
pressure the parts of the two substances are forced into
such close contact, that an agitation and emission of the
fluid pervading their substance takes place. This agitation,
as we have already noticed, is heat itself, and, as
long as the friction is continued, more and more heat
will be produced, without any limitation, as Count Rumford
has observed.
Some bodies have a greater disposition than others to
emit this subtile fluid; and these we say are naturally
of a warmer temperature than others. The temperature
is nothing else than the efflux of the fluid from them,
continually kept up by the action of the surrounding
fluid. By mixture with different substances the
temperatures of various bodies may be changed; by
some the influx, and by others the efflux, may be augmented.
In the former case we say the body becomes
colder, in the latter hotter, than before; and in not a
few cases the agitation of the fluid becomes so great that
the matter actually takes fire. In all these cases, however,
we can discover nothing more than the bare
fact, that so and so is the case. We know that the
bodies do grow hot by the convergence of the etherial
fluid towards them, and its emission from them; but
why it should converge or diverge we know not.
Thus much with regard to heat in general. We must
next consider another fluid which has very generally been
accounted the source and fountain of heat, viz. air.
This is indeed so much the source of heat in all our
operations, that it was natural to think it the only one;
but experiments have now determined that air itself
is a mere creature of heat and light;79 for, by employing
these in a proper manner, airs or gases of all
kinds have been produced. Thus, by exposing water in
a glass vessel for some time to the rays of the sun, a
quantity of very pure oxygen air may be obtained; by
concentrating the sun’s rays upon charcoal, inflammable
air may be had; and by distilling, with a strong heat,
substances of various kinds, we may obtain a great variety
of aerial vapours. From all this we may reasonably
conclude that heat, attached to some other substance,
dissolved in it in such a manner as to become
invisible, forms the substance of air. Heat therefore
being the agent in the composition of air, it is reasonable
to suppose that it is the agent in its decomposition
also, or in its transformation from one species to
another, of which the conversion of oxygen into fixed
air by combustion is an instance. When air is
taken into the lungs the blood is warmed by the
action of that invisible fluid, which has already given
elasticity to the air. In consequence of a considerable
quantity of this fluid being then converted from
a latent into a sensible state, part of the elastic principle
must be lost, and the air diminished in bulk. The reason
why this must constantly take place is, that part of
the heat evaporates from the surface of the body, during
the course of circulation. Were it not so, the quantity
thrown out by the lungs would be exactly equal to that
which the blood received, and consequently there could
be no diminution between the bulk of the air expired
and that which was inspired; but, on account of the
waste just mentioned, the blood must always receive
somewhat more than it gives out by the breath. Thus,
while the air we breathe continues the same, and the organization
of the body is not changed, the natural operations
will go on smoothly, and health will continue;
but, as we have formerly observed, by an alteration of
either of these, disease must ensue; and we must now
endeavour, from the principles laid down, to examine
the mode in which epidemic diseases, and particularly
the plague, may be produced.
The air is so evidently connected with human life, that
it has been from the earliest ages accounted the source
of pestilential diseases, though, as none of the more obvious
qualities of it, such as heat, cold, moisture, or
dryness, appeared to be connected with them, they were
generally supposed to proceed from the action of some
unknown natural cause, or from that of the Deity himself.
Some, however, have also been of opinion that
plagues might originate from the obvious qualities of
the air in conjunction with certain effluvia from putrid
vegetable or animal bodies. Thus, in several plagues
mentioned in ancient history, we find swarms of dead
locusts, grasshoppers, the carcases of those slain in battle,
crowded houses, and filth of all kinds, assigned as
causes. This opinion was adopted by Dr. Mead, and
he gives the following account of the origin of the
plague in Egypt. “Grand Cairo is crowded with inhabitants,
who for the most part live very poorly and
nastily; the streets are narrow and close; it is situate
in a sandy plain, at the foot of a mountain, which,
by keeping off the winds that would refresh the air,
makes the heats very stifling. Through the midst of
the city passes a great canal, which is filled with water
at the overflowing of the Nile; and, after the river
decreases, is gradually dried up: into this canal the
people throw all manner of carrion, filth, &c. so that
the stench which arises from this and the mud together
is insufferably offensive. In this posture of things,
the plague every year preys upon the inhabitants, and
is only stopped when the Nile, by overflowing, washes
away this load of filth; the cold winds, which set in
at the same time, lending their assistance by purifying
the air.” He then proceeds to account for the plagues
in Ethiopia in the manner above related, viz. by the
prodigious swarms of locusts, which sometimes occasion
a famine by devouring the fruits of the earth, and, when
they happen to be cast by the winds into the sea, occasion
a pestilence; the putrefaction being heightened
by the intemperance of the climate, which here is
so great that it is infested with violent rains for three
or four months together; and it is particularly observed
of this country, that the plague usually invades it whenever
rains fall during the sultry heats of July and August.
He next takes notice of what the Arabians say
of the origin of the plague in Ethiopia, viz. that it is
brought on by unseasonable moistures, heats, and want of
winds. But, whatever truth may be in the account
given of the Ethiopic plagues, the testimonies already
produced in this treatise are sufficient to render it very
doubtful, at least, whether the plague ever does originate
in Cairo, or any other place in Egypt. Besides, if
we once admit the existence of any thing as a cause adequate
to the production of a certain effect, wherever that
cause exists the effect ought certainly to follow, unless
where we plainly perceive something which prevents its
action. It is not fair reasoning to say that the action of
the cause is prevented by something unknown, for we
might as well say that this unknown something is the
cause originally, and acts only upon certain occasions, of
when it thinks proper. Now, if the filth of the canal
of Cairo be the cause of the plague in that city, it ought
to recur annually at the season when that filth exists in
greatest quantity, and in the most putrid slate. Nevertheless
we have the express testimony of Mr. Eyles Irwin,
that at the time he was in Cairo there had not been any
plague for seven years. The account he gives of it is a
kind of contrast to that above quoted from Dr. Mead.
“Misir al Kaira, says he, or the City of Anguish, so called
from the frequent visits which it has received from the
plague, but commonly called Grand Cairo by us, is situated
in lat. 30 degrees 3 minutes N. on an artificial
branch of the Nile. Old Cairo nearly faces the river;
but the new city is removed above a mile from it, and
approaches to the range of mountains which runs
through Upper Egypt, and abruptly breaks off here.
It is undoubtedly one of the finest cities in the east;
which, from the present style of architecture that reigns
among the orientals, is but a faint commendation.
The houses are in general built of stone, and, being
elevated to several stories, would make a grand appearance,
notwithstanding the inelegance of their
structure, were not the effect destroyed by the excessive
narrowness of the streets. This is one of the
causes to which the ingenious Dr. Mead ascribes the
birth of the plague in this capital; but experience
evinces that it arises from foreign and adventitious causes.
There has not been a plague here these seven years; which
is rendered more remarkable by the commencement
of the Russian war at the date of its cessation. No
one can account for this; though a year seldom passed
by before without a visit from it.”80
From this it plainly appears, that, however these putrid
effluvia may concur with other circumstances in producing
the plague, they are by no means the only cause;
otherwise not a single year could have passed in Cairo
without a pestilence; and the very same thing we shall
find to hold good in every other, let us choose for a
cause what we will. In order to investigate this matter
fully, we must now consider what causes have been assigned
by physicians for other epidemical diseases; and
here, to avoid prolixity, we shall chiefly confine ourselves
to those enumerated by Dr. Fordyce as the causes of
fever; a gentleman whose very extensive experience
must give the greatest weight to his testimony.81 The
principal causes assigned by him are,
1. Infection, or “a peculiar matter generated in the
body of a man in fever, which is carried by the atmosphere,
and applied to some part of the body of a
person in health, and which causes fever to take place
in him.” That such a cause exists, he proves from observing
that “of any number of men, one half of whom
go near a person ill of a fever, and the other half do not,
a greater number of the former will be infected, in a
short period afterwards, than in those who do not.”
He says he has known, in such circumstances, seven out
of nine infected with the disease. This infection is not
discoverable by smell or any other organ of sense; neither
can the greatest attention to cleanliness disarm it of
its malignity. Of this the Doctor says that he has known
instances; nay, of a person going into a room where a
feverish patient was, and bringing with him the infection,
which was communicated to others in the room to which
he came. He owns, however, that by allowing the air
to stagnate in which feverish patients are, the infection
will become extremely violent and fatal. This may naturally
be supposed, even without having recourse to
putrid effluvia; because, independent of these, the imperceptible
infectious matter itself will undoubtedly be
accumulated in the atmosphere of the room, and act
more powerfully than it could have done had it been
partly carried off and diluted by attention to cleanliness
and ventilation. He also says, that “when a number
of persons live in a small space, supposing even that they
are kept as clean as possible, it happens frequently that
fever arises in some, often in many of them. It has
been in this case supposed, and is extremely probable,
that some peculiar species of matter is produced, capable
of producing fever, on being applied to the body.”
2. Effluvia from putrid animal or vegetable matters.
Of this our author seems to be less fully ascertained than
of the former, as he does not say that he has observed
any instances of fevers arising from this cause; and he
concludes by observing that “either the cause of fever,
consisting of matter produced in the body of a person
affected with this disease, seems probably different from
that produced by putrefaction, or might be generated
without any putrefaction taking place.”
3. Cold. Our author “is not disposed to allow that
sudden exposure to cold occasions fever to take place,
unless some symptom of the disease follows immediately.
If a man had been suddenly exposed to cold, and continued
in perfect health for twenty-four hours, the author
would never allow that fever, or any other disease,
was occasioned by it. In this case (exposure to cold)
the evidence is much stronger than in that of infection;
for the author (Dr. Fordyce) has seen many
instances where, from exposure to cold, the commencement
of the attack was instantaneous; and many are
to be found in the records of medicine.”
4. Moisture. On this subject the Doctor observes, that
the application of water to the body is not a cause of fever,
unless the air has particles of water floating in it; in
which case fever has ensued more frequently than in
other cases. Water may exist in the atmosphere in
three states. 1. In small drops suspended in it like dust
in water. 2. In vapour. In this case the transparency
of the air is not impaired, and a chemical combination,
as it is called, between the air and water takes place.
If the atmosphere be hot or dense, it is capable of combining
chemically with a larger proportion of water. If
therefore the atmosphere should in this manner be saturated
with water, at any particular degree of heat or density,
by diminishing either of these the vapour will be
condensed, and the water reduced to the former state of
suspension in small particles. 3. Water, heated to the
boiling point, emits a steam, which combines chemically
with the atmosphere, till the latter be saturated, after
which it assumes the form of small particles; and this
last is the only state which has been found to produce fever.
Moisture will also produce fever when applied to the
body by wearing wet clothes. Those which imbibe or
part with heat most slowly, are least apt to produce fevers
on being heated. The warmer the atmosphere, the more
liable people are to fevers from moisture.
It has been observed, that moisture from marshes,
stagnating canals, or where the water runs very slowly,
is more apt to produce fevers than what proceeds from
the sea, lakes or rapid rivers. “This (says the Doctor)
has given occasion to suppose that some other vapours
proceed from such marshes beside water, and produce
the disease. It certainly often happens, that a considerable
degree of putrefaction takes place in marshy
grounds, and more especially in warm climates; but
it is by no means to be concluded that moisture in the
atmosphere always produces fever in consequence of
putrefaction. Putrefaction can only take place in vegetable
or animal substances. If water therefore, not
impregnated with either, should be in such a situation
as to produce moisture in the atmosphere, no putrefaction
can take place; therefore, if fevers ensue, they
are certainly in consequence of moisture, not putrefaction.
Many instances of this may be brought, as in
the war which took place in Flanders, between the
tenth and eleventh year of the present century, an army
encamped upon sandy ground, in which water was
found in digging less than a foot deep, and occasioned
a great moisture in the air, which produced in a few
days numbers of fevers, although the army was perfectly
healthy before, and no more fevers were produced
on shifting their ground. There are a vast many
other instances of the same thing having taken place.
Besides, fever has often arisen immediately in persons
sitting in rooms, the floors of which had been just
moistened with pure water.”
5. Certain kinds of food. On this Dr. Fordyce observes,
that, though food of difficult digestion undoubtedly
produces a number of diseases, he has never seen it
productive of fever excepting once. Dr. Girtanner relates,
that the emperor of Germany, having forced a
number of his subjects to serve as soldiers, and sent them
into an unwholsome part of Walachia, where he fed
them with a kind of paste made of bread and water instead
of meat, many of them died of the scurvy. The
Doctor, however, does not ascribe this to any positive
cause, but to three negatives, viz. the abstraction of the
stimulus of nutriment, by feeding on the paste just mentioned;
of the stimulus of oxygen in the corrupted atmosphere
of Walachia; and lastly of the nervous stimulus,
the most powerful of all; the greatest part being engaged
by force against their will. This corroborates what Dr.
Fordyce has said, that bad food is very seldom the cause
of fever; for among so many, who used the imperial
paste just mentioned, some would certainly have been
affected by fevers, had it been capable of producing
them; but, as it did not, it is most evident that the
deficiency of stimuli is not the cause of fever.
6. Passions of the mind. These are looked upon by
Dr. Fordyce to be among the less frequent causes of
fever, though it is certain that they have been productive
of multitudes of diseases, and even of sudden
deaths; and Dr. Falconer, in his Prize Dissertation,
ascribes to the passions very considerable effects in fevers,
and even in the plague itself. “Contagious fevers
(says he) afford strong instances of the influence
of mental affections, both as prophylactics and remedies.
The plague is a remarkable example, and the
same reasoning extends to other disorders of a febrile,
contagious nature. Fear, it is well observed by Dr.
Cullen, by weakening the body, and thereby increasing
its irritability, is one of the causes which, concurring
with contagion, render it more certainly active,
which he ascribes to its weakening effect on the body,
by which its irritability is increased. Against this
therefore he directs the mind to be particularly fortified,
which is best done by giving people a favourable
idea of the power of preservative means, and by destroying
the opinion of the incurable nature of the
disorder, by occupying the mind with business or labour,
and by avoiding all objects of fear, as funerals,
passing-bells, and any notice of the death of particular
friends. Even charms might be used with good effect,
could we promote a strong prepossession of their efficacy,
either by the confidence they inspire, or by their
engrossing the attention of the mind. It is no less
certain, that a studious regard to promote hope and
confidence in recovery, is equally necessary for the
cure as for the prevention of such disorders. We
know that contagious fevers have a peculiar tendency
to diminish the energy of the brain, and of course to
debilitate the whole system; and that this is especially
the case with the plague, which produces the most considerable
effects in weakening the nervous82 system or
moving powers, and in disposing the fluids to a general
putrescency; and Dr. Cullen is of opinion that to these
circumstances, as the proximate causes of the plague,
regard should chiefly be had, both for the prevention
and cure of this disorder. It must therefore be highly
necessary, during the course of this disease, to attend
to the support of the spirits, as on these the vital principles
greatly depend; and they can by no means be
so effectually kept up as by inspiring a confidence of
recovery.”
Dr. Zimmerman presents us with a great number of
examples of the influence of the passions in producing
diseases, or death itself; some of the most remarkable of
which follow. “All the passions (says he) when carried
to excess, bring on very formidable diseases. Sometimes
they occasion death, or bring us at least into
imminent danger. The most reputable physicians agree
in opinion that terror may occasion apoplexy, and
death; and indeed they consider apoplexy as the most
common effect of violent passion. Without being
carried to excess, a passion will sometimes occasion a
difficulty of breathing, together with a sense of stricture
in the breast, and an hesitation to speak; the
tongue remaining as it were immoveably fixed on the
palate. Hysterical and hypocondriacal affections are
sometimes the effects of grief in the most healthy people.
Joy is much more dangerous to life than sudden
grief. Sophocles died through joy at being crowned
on account of a tragedy he had composed in his old
age. The famous Fouquet died on being told that
Louis XIV had restored him to liberty. The niece of
the celebrated Leibnitz, not suspecting that a philosopher
would hoard up treasure, died suddenly on
finding under her uncle’s bed a box containing sixty
thousand ducats. Violent anger has sometimes produced
hæmorrhages and subcutaneous extravasations;
or, some vessel of the brain being ruptured by these
transports, a fatal apoplexy has taken place. There
have been instances of excessive anger being succeeded
by epilepsy, colic, or a violent degree of fever. Sometimes
it has occasioned an increased flow of bile. In
some this produces vomiting; in others it goes off
downwards, and causes diarrhœa; or being retained,
from a stricture of the gall-ducts, will perhaps be absorbed,
and occasion jaundice. In cases where anger
has been succeeded by extreme grief, obstructions have
taken place in the liver. The effects of terror are
similar to those of anger, but in general more violent.
Sometimes excessive terror seems to give to men a preternatural
strength, as is the case with madmen and drowning
persons. In some cases it has not only excited immediate
convulsions, but caused them to return periodically.
Fear has been said to make the hair stand
upright, and to contract the pores from which the hairs
issue in the same manner as cold does. There are instances
in authors even of the colour of the hair being
changed by excessive fright. Philip V died
suddenly on being told that the Spaniards had been
defeated, and, on opening him, his heart was found
ruptured. Timid people are more liable than others
to fall sick. A firmness of mind is one of the best
preservations against contagion. Willis has very well
observed, that they who fear the small-pox the most
are generally the first to be attacked with it. Cheyne
assures us that fear is extremely prejudicial in all epidemical
diseases. Dr. Rogers remarks, that fear constantly
increases the ravages of a contagious disease.
Rivinus attributed the propagation of the plague at
Leipsic wholly to fear. The French physicians, who
wrote on the plague at Marseilles, went so far as to
deny its being contagious, and ascribed its propagation
chiefly to fear.”
As for the cause of the plague itself, Dr. Fordyce supposes
it to be produced by an infection of a particular
kind. That which takes place in Syria and Egypt, he
says, has only been clearly described by Dr. Russel; and
it cannot be gathered from the accounts whether this
may be originally produced without having been propagated
as the first class of infections above mentioned are.
“That disease (says he) called the plague, which ravaged
this country (England) on considering the histories of
the disease, seems to have been a fever,83 produced by
infections of the first class which have been enumerated.”
Dr. Moore has given an account of the origin
of a plague, which, if it could be depended upon,
would decide the question concerning the origin of this
dreadful distemper without previous infection. This
passage is extracted from the History of the Royal
Medical Society for the years 1777 and 1778. “Dr.
Mitchell, physician to the hospital at Smyrna, appears,
according to a memoir of which he is the author,
sent by M. le Baron de Tott to the Medical
Society to believe in the spontaneity of the plague
(or that it arises of itself without any predisposing
cause in the body) for proof of which he cites the
following circumstance: A solitary shepherd, having
no communication with any body, fell sick while he
was tending his flocks; he went into an inhabited
part, where he communicated the plague with which he
found that he was attacked. This circumstance would
prove much, if it was certain that the shepherd had
no communication with others; if it were known how
long, and with what precaution, he had been secluded
from company: but the proofs of these are too difficult
to be established to allow of any conclusion to be
drawn from the fact. We are obliged therefore to acknowledge
[it to be a doubtful matter] whether it is
in fact a country that is the cradle of the plague;
what country this is, supposing that such an one exists;
or, finally, whether it sometimes appears spontaneously,
and whether the first whom it attacks becomes
the focus from whence it emanates.”
Dr. Fordyce, in treating of the origin of fever, seems
inclined to think that it may arise without any predisposing
cause; and after having enumerated the various
causes already mentioned, and fully considered them,
gives it as his opinion, that “there must undoubtedly
be other causes than those which give occasion to the
disease, but which are at present totally unknown.”
In like manner Dr. Moore, speaking of the nervous
fever, sums up what may be known concerning the
cause of it in the following words. “Upon the whole,
we know that people of delicate, exhausted and sickly
constitutions, and those whose minds are saddened by
depressing passions, are greatly predisposed to this disease,
the immediate seeds of which, we also know,
may be generated in places where human effluvia are
collected and confined. And this is the most essential
part of our knowledge respecting the cause of this
disease; and even this little is disturbed with uncertainty:
for we sometimes meet with instances of people
of robust constitutions, who are seized with the disease
in all its malignity, when they are under no depressing
passion, when the disease is not epidemic, to
whom we cannot trace it from any place where the
human effluvia could be confined in any uncommon
degree, or from any person in the disease, of which
perhaps there is no other person ill in the neighbourhood
for several miles round; and, in short, when we
cannot connect it with any of the causes supposed to
be the sources of the distemper. On extraordinary
occasions of this kind we have nothing for it but to
suppose that, notwithstanding the apparent vigour of
the patient, his body has been peculiarly predisposed
to catch the infection, and that some contagion, not
forcible enough to infect any other person, has by some
means, unobserved, been conveyed to him; or, if so
many suppositions displease, we may suppose at once
that there is in some cases a source of this fever which
has not been suspected. For, although the numerous
observations that have been made give us the strongest
reason to think that human effluvia produce this disease,
we have no right to infer that it cannot arise also
from some other source.”
To the same purpose I subjoin the very respectable
opinion and testimony of Dr. Patrick Russel. “In some
epidemical distempers, the sudden alternations of the
air have constant and manifest influence; in others,
though the influence of the air must be equally admitted,
it seems not to depend on sensible alteration
or succession in the common properties of the atmosphere,
but on some inexplicable combination, some
occult, new, unknown quality. Amongst epidemics of
this last kind must be reckoned the plague. . . . Should
ever that state of the air, without the concurrence
of which the contagion of the pestilence never
spreads, or ceases to act, be discovered, and ascertained
by unequivocal marks, the dread of the plague,
universally prevalent, would be greatly diminished;
more effectual means of preservation would be found
out, and the application of them might safely be limited
to certain seasons.
“Experience in Turky, where, generally, no precautions
are taken in the times of pestilence, clearly evinces,
that, in a certain state of the air, a communication
with infected places may subsist without any material
consequence. The return of the plague at Aleppo
happens at irregular periods; the intervals are of considerable,
but unequal, length; and in those the commerce
with Egypt, Constantinople and Smyrna remains
uninterrupted. In the intervals between 1744
1760, and from 1762 to 1780, the plague raged several
times in the places now mentioned, without affecting
Aleppo; and even in two or three years subsequent
to 1762, though it was at Marash, as well as
other places not far distant, with which Aleppo has
continual intercourse, no instances were discovered of
communicated infection: if such happened, they must
have escaped my utmost vigilance; and the daily
exercise of my profession led me to be very much
among the natives of all ranks. At the same time I
have reason to suspect that infected families from some
of those places took refuge in Aleppo; and I know,
with certainty, that not only some merchants of that
city, who happened to be at Marash when the plague
broke out there, returned to their families in the summer
of 1763, but that caravans of various merchandise
arrived in the course of the same summer.
“I consider it therefore as an established fact in the
Levant, that commerce and intercourse with infected
towns is sometimes attended with no bad consequence.
The same thing may perhaps be asserted, without
restriction, of all countries; but till the signs indicating
a pestilential constitution be ascertained, no particular
year can be declared exempt from danger. Predictions
founded on planetary conjunctions have been
long exploded; and signs derived from the known
properties and alterations of the air, are almost equally
fallacious. The seasons concomitant with plagues in
England, as well as elsewhere, have been very dissimilar;
and the same visible concurrence, usually deemed
pestilential, has often, in the revolution of years, been
observed to return, in various countries, without producing
the dreaded consequences. Upon the whole,
from all I have been able to collect, the pestilential
constitution seems hitherto to be known only from its
effects; neither its approach nor its retreat can be predicted
and its nature remains wrapped up in MYSTERIOUS
DARKNESS.”
Having thus seen, that, of the causes commonly assigned
for epidemical diseases, not one can be accounted
certain and determinate, it now remains to consider one
more, and that is
Contagion. Though this has been generally accounted
the same with infection, yet by some it has been reckoned
otherwise; and indeed there seems to be a necessity
for such a distinction; for, though we should prove,
ever so clearly, that a disease once communicated to one
person should from that person be communicated to another,
yet the difficulty is to know from whence the first
person had it. This source, if any such can be found,
is what we may with the greatest propriety distinguish by
the name of contagion, and is the sense in which it shall
for the future be used in this treatise, the matter communicated
from one person to another being always called
infection. This indeed differs from what many celebrated
physicians have said upon the subject; but the distinction
certainly must exist. Dr. Cullen speaks rather indistinctly
upon the subject. “We have supposed that
miasmata are the cause of intermittents, and contagions
the cause of continued fevers, strictly so named; but
we cannot with propriety employ these general terms.
The notion of contagion properly implies a matter arising
from the body under disease, miasma, a matter
arising from other substances. But, as the cause of
continued fevers may arise from other substances than
the human body, and may in such cases be called a
miasma, and, as other miasmata also may produce contagious
disorders, it will be proper to distinguish the
cause of fevers by using the terms marsh, or human effluvia,
rather than the general ones miasma, or contagion.”
From this it is not very easy to determine what the
Doctor means when he speaks of specific contagion as the
cause of the plague. Dr. Russel plainly ascribes it to
human effluvia. “The plague (says he) is a contagious
disease; that is, an emanation from a body diseased, passing
into one which is sound, produces, in time, the
same disease,” &c. There must, however, undoubtedly
have been something originally distinct from the
human body which gave rise at least to the first plague
that was in the world; and some plagues recorded in
history are said to have arisen in this way. Thus, Ammianus
Marcellinus says that the plague which broke out
in the Roman army in the time of Marcus Aurelius
arose from a pestilential vapour confined in a golden coffer
dedicated to Apollo. Upon opening this, the contagion
diffused itself all around, and the infection spreading
from one to another, produced an almost universal pestilence.
Ammianus indeed is the only historian who
relates this; another account of its origin is given, p.
14, but whether we believe the account of Ammianus
or not (which indeed does not appear probable) it is sufficient
to show what were the received opinions at the
time. In like manner every one has heard of pestilential
effluvia breaking out from the earth, from graves, &c.
so that we certainly look upon this doctrine of contagion
as the cause of diseases to have been pretty generally received.
We are also informed by Dr. Mead, from M.
Villani, who wrote the history of those times, that the
great plague of 1346 began in China, where, according
to the report of some Genoese sailors, it was occasioned
by a great ball of fire that either burst out of the earth,
or fell down from heaven. This is thought incredible
by Dr. Mead, and no doubt is so, but it shows the general
opinion, that the original cause or contagion which
produces a plague is distinct from the infection which is
afterwards communicated from one to another. In the
French Encyclopedie, we have this account of the ball
of fire, or fiery vapour, without any comment.
As to the opinion of pestilential vapours arising out of
the earth, though we are assured that people have been
suddenly killed by explosions, probably of the electrical
kind, or by lightning issuing from under their feet, yet
we are not furnished with any well authenticated accounts
of a plague having arisen from any such cause.
About 19 years ago a violent fever raged epidemically
through a small district in the north of Scotland, which
was said to have originated in the following manner.
Some young men having heard that a certain place in
their neighbourhood had, in the time of a plague been a
burial ground, took into their heads to dig into it.
They did so, and one of them immediately fell sick, but
recovered. The father of two of the young men, exceedingly
displeased at the conduct of his sons, and apprehensive
of the consequences, filled up the hole they had
dug in the ground, soon after which he fell sick and died,
and the fever continued to rage in the neighbourhood
for some time. The mother of another of the parties
concerned also died, and boils broke out on various
parts of the bodies of the sick. This was the account
given in some of the news-papers of the time, and had
the matter been thoroughly investigated and attested,
would have been decisive in favour of pestilential contagion
being capable of taking up its residence in the
earth. As it stands at present, it can only draw our attention
to what may happen in another case, should any
similar one occur.84
With regard to epidemics occasioned by the action of
electricity, we cannot indeed produce any instance; but
we have one of a distemper more dreadful than even the
plague itself; and that is of a person suddenly struck by
an electric flash (generated either in his own body, or
in the room where he was) and by this stroke reduced
to a most deplorable condition, which soon ended in
death. The account stands on the authority of Mr.
Joseph Battaglia, surgeon at Ponte Bosio, who transmitted
it to Florence, and is as follows.
“Don G. Maria Bertholi, a priest residing at mount
Valere in the district of Livizzano, went to the fair
of Filetto, on account of some business which he had
to transact, and after spending the whole day in going
about through the neighbouring country, in order to
execute commissions, in the evening he walked towards
Fenille, and stopped at the house of one of his
brothers-in-law, who resided there. No sooner had he
arrived, than he desired to be conducted to his apartment,
where he put a handkerchief between his shoulders
and his shirt, and, when every body retired, he
began to repeat his breviary. A few minutes after, a
loud noise was heard in Mr. Bertholi’s chamber; and
his cries having alarmed the family, they hastened to
the spot, where they found him extended on the floor,
and surrounded by a faint flame, which retired to a
greater distance in proportion as it was approached,
and at length disappeared entirely. Having conveyed
him to bed, such assistance as seemed necessary was
given him. Next morning I was called, and after
examining the patient carefully, I found that the teguments
of the right arm were almost entirely detached
from the flesh, and hanging loose, as well as the skin
of the lower part of it. In the space contained between
the shoulders and the thigh, the teguments were
as much injured as those of the right arm. The first
thing, therefore, to be done, was to take away those
pieces of skin; and, perceiving that a mortification was
begun in that part of the right hand which had received
the greatest hurt, I scarified it without loss of time;
but notwithstanding this precaution, I found it next
day, as I had suspected the preceding evening, entirely
sphacelous. On my third visit, all the other wounded
parts appeared to be in the same condition. The patient
complained of an ardent thirst, and was agitated
with dreadful convulsions. He voided by stool bilious
putrid matter, and was distressed by a continual
vomiting, accompanied with a violent fever and delirium.
At length the fourth day after a comatose
sleep of two hours, he expired. During my last visit,
while he was sunk in the lethargic sleep of which I have
spoken, I observed with astonishment, that putrefaction
had already made so great progress, that his
body exhaled an insupportable smell. I saw the
worms which issued from it crawling on the bed,
and the nails of his fingers drop of themselves; so
that I thought it needless to attempt any thing farther,
while he was in this deplorable condition. Having taken
care to get every possible information from the patient
himself, respecting what had happened to him, he told
me, that he had felt a stroke, as if somebody had given
him a blow over the right arm, with a large club, and
that at the same time, he had seen a spark of fire attach
itself to his shirt, which in a moment was reduced to
ashes, though the fire did not in the least injure the wrist-bands.
The handkerchief which he had placed upon
his shoulders, between his shirt and his skin, was perfectly
entire, without the least appearance of burning,
his drawers were untouched, but his night-cap was destroyed,
though a single hair of his head was not hurt.
That this flame under the form of elementary fire,
burnt the skin, reduced the shirt to ashes, and entirely
consumed the night-cap, without in the least touching
the hair, is a fact which I affirm to be true: besides,
every symptom that appeared on the body of the deceased,
announced severe burning. The night was
calm, and the circumambient air very pure: no bituminous
smell could be perceived in the chamber, nor
was there the least trace of fire or of smoke. A lamp,
however, which had been full of oil, was found dry,
and the wick almost in ashes. We cannot reasonably
suppose this fatal accident to have been occasioned by
any external cause; and I have no doubt that if
Maffei were still alive he would take advantage of it
to support an opinion which he entertained, that lightning
is sometimes kindled in the human body and
destroys it.”
Another account, to the same purpose, is given in
Mr. Battaglia’s paper. “On the 21st of April, 1781,
the first battalion of the brigade of Savoy set out from
Tortona, in order to go to Arti, when the weather was
excessively hot. On the 22d, having made rather a
forced march, the soldiers suffered a great deal from
the ardour of the sun, so that, at the village of Serre,
where they halted, one of them, named Bocquet, a
man of twenty-five years of age, whose skin being very
hard and thick had not perspired, sent forth a loud
cry, which seemed to announce some extraordinary
commotion, and instantly fell down. Mr. Bianet,
surgeon major to the regiment, found the patient in
convulsions. When he was carried to the hospital
the upper part of his body, to the thighs, appeared to
be withered and black, and in a gangrenous state.
Mr. Bianet employed scarifications, but without effect;
it was impossible to make him swallow any
thing; and it was found necessary to abandon him to
his dismal fate. His body soon exhaled a putrid
smell, and he died at the end of five hours. That his
disorder might not be communicated to others, he
was interred together with his clothes. Upon inquiry,
after his death, it was found that this man was
addicted to the constant use of spiritous liquors, and
that he had even drank of them to excess upon the
march.”
Other instances there are, still more terrible, of people
actually taking fire and being consumed to ashes by
some internal cause; but, as nobody was present either
at the beginning or during the continuance of these extraordinary
inflammations, nothing certain can be said
about them. That such things, however, have happened,
is certain, of which one of the most remarkable
instances is that of Signora Corn. Zangari, an Italian
lady. She retired to her chamber in the evening somewhat
indisposed, and in the morning was found in the
middle of the room reduced to ashes, all except her face,
legs, skull and three fingers. The stockings and shoes
she had on were not burnt in the least. The ashes were
light, and on pressing them between the fingers vanished,
leaving behind a gross, stinking moisture,
with which the floor was smeared; the walls and furniture
of the room being covered with a moist cineritious
soot, which had not only stained the linen in the
chests, but had penetrated into the closet, as well as into
the room overhead, the walls of which were moistened
with the same viscous humour. This lady had been
accustomed to use a bath of camphorated spirit of wine
when indisposed.
Dr. Zimmerman, from the 64th volume of the Philosophical
Transactions, relates the case of a poor woman
who perished in this miserable manner at Coventry
in England in the year 1772. “She fell out of bed,
and was found next morning burnt to death, though
the fire in the grate had been small, and the furniture
in the room had suffered but little. Except one
thigh and leg, there were not the least remains of any
skin, vessels or viscera; and the greater part of the
bones were completely calcined, and covered with a
whitish efflorescence.”
On these unfortunate people it has been observed
that they were generally intemperate in the use of spiritous
liquors. Of the poor woman at Coventry, whose case
has been just now related, it is said, that she had been
in the practice of drinking from half a pint to a quart
of rum every day, and this she continued, notwithstanding
her being affected with jaundice and other complaints.
Mr. Wilmer, who communicated this case to the Royal
Society, concludes it with these words: “That her
solids and fluids were rendered inflammable by the
immense quantity of spiritous liquors she had drank,
and when she was set fire to she was probably soon
reduced to ashes.”
On other cases of a similar nature it has been remarked,
that the miserable sufferers were “for the most
part advanced in years, remarkably fat, and had been
much addicted to the use of spiritous liquors, either
in their drink, or applied in friction to the body;
whence it has been concluded that these people perished
by their whole substance spontaneously taking
fire, the principal seat of which had been the entrails,
or the epigastric viscera; and that the exciting cause
was naturally found in the phlogiston of the humours,
called forth by that of the spiritous liquors
combined with them.”85 But solutions of this kind
cannot by any means be admitted. We have not the
smallest reason to think that either the solid or fluid
parts of the bodies of hard drinkers are more inflammable
than those of other people; neither is it credible that
any person could live with his body in such a state. Besides,
the most inflammable bodies will not begin to
burn unless fire actually be applied to them, while others
much less inflammable to appearance, will yet take fire
spontaneously. Thus, even spiritous liquors themselves,
though they flame violently when thrown into a fire, or
when a burning body is applied to them, yet there is
not an instance of such liquors taking fire of themselves;
nay, they cannot even be set on fire by pouring them upon
a red-hot iron, while, on the other hand, heaps of
wet vegetables, which we should think scarce at all inflammable,
do yet very frequently take fire spontaneously.
The author lately quoted, however, justly observes that
M. Bartholi, the unfortunate priest above mentioned was
plainly struck first by electricity from without, a spark of
fire attaching itself to his shirt, and a faint flame surrounding
his body; so that the fire did not seem to have
been generated in his body, but in the atmosphere.
There are instances of people being surrounded with these
luminous appearances without being hurt; particularly
of a woman at Milan, whose bed was surrounded with
a light of this kind. Mr. Loammi Baldwin, of this
country, was also surrounded by an electric light, while
raising a kite in the time of a thunder storm, and Dr.
Priestley makes mention of a gentleman, who, after having
worked an electric machine for a long time in a
small room, perceived, on leaving it, a luminous vapour
following him. But the instances most to our present
purpose are some recorded in the Philosophical Transactions,
of luminous vapours coming from the sea, attaching
themselves to corn-stacks, and setting fire to them.
One of this kind is particularly mentioned in Lowthorp’s
Abridgement of the Transactions, as having taken place
in Ireland, coming repeatedly from the sea, and setting
fire to corn and hay, so that the people were greatly
alarmed. At last they found that it might be driven
off by making a great noise, and that it would avoid any
sharp-pointed iron instrument. Had such a vapour attached
itself to a human body, it is possible that it might
have set fire to it as well as to the stack of corn or hay.
Whether these accounts render the story of the Genoese
sailors concerning the ball of fire occasioning the plague
of 1346 more credible, we leave the reader to judge.
They certainly show, however, that the electric fluid will
sometimes interfere with the human body in a very terrible
manner, producing, where it does not kill instantaneously,
symptoms equal to those of the very worst
plague, as in the case of the priest and soldier above
mentioned.
Another hypothesis concerning the origin of pestilential
diseases is that of swarms of little animals invisibly
existing in the atmosphere; which, being taken into the
body by the breath, are supposed to corrupt or otherwise
vitiate the blood and other parts of the body, as we
see in the plague and other epidemic disorders. This
hypothesis, so generally exploded, and so apparently improbable,
seems to receive some support from a discovery
of an insect made by Mr. Henry Baker, F. R. S. and published
in his work entitled “The Microscope made Easy.”
He called it the insect with net-like arms. “It
lives (says he) only in cascades, where the water runs
very swift. Some of them being kept in a vial of water,
most died in two days, and the rest, having spun themselves
transparent cases, which were fastened either to
the sides of the glass, or to pieces of grass put into it,
seemed to be changed into a kind of chrysalis; but
before they assumed this form, they altered their shape
(in a manner he represents by a figure.) None of them
lived above three days; and, though fresh water was
given them two or three times a day, yet in a few hours
it would stink to a degree scarce conceivable, and that
too at several yards distance, though, in proportion to the
water, all the included insects were not more than as
one to one million, an hundred and fifty thousand. This
makes it probable that it is necessary for them to live
in a rapid stream, lest they should be poisoned by the
effluvia issuing from their own bodies, as no doubt
they were in the vial.”
From this account it is not difficult to conceive that
animals, though exceedingly small, may yet emit such
poisonous effluvia as will destroy much larger ones in
their neighbourhood. It will by no means be incredible
that, had one or two such offensive animals been
thrown into a jar containing gold-fishes,86 the whole of
these beautiful inhabitants would have perished at once.
Let us suppose such a thing to have actually happened;
that a malicious person had put them in over night, and
in the morning the proprietor of the fishes finds them all
dead, and the water offensive to the last degree. He
sends for a neighbouring philosopher, who, happening to
be ignorant of the existence of such animals, endeavours
to account for the phenomenon upon some of the received
principles of philosophy. How much theory would
here be wasted, and what endless disputes might ensue
without even a possibility of arriving at the truth! Just so
it is with epidemic diseases. The cause is invisible, and,
until it becomes discoverable by our senses, it can never
be known; for, as has already been observed, a cause
never can be known merely by its effects, unless we have
seen it, or somebody who has seen it gives us information.
And this will certainly be found to hold good in
every instance, even from the Supreme Cause himself to
the diminutive insect just mentioned.
Lastly, I shall consider another possible source of epidemics,
which has been hinted at by others. Allowing
that infectious matter proceeds from the body of a diseased
person, as much must issue from a single patient
as is sufficient to bring the disease upon thousands, and
with regard to the small-pox and some other distempers
we certainly know that it is so. This infection is dissipated
in the atmosphere, and intimately combined with
it, so that it becomes imperceptible and harmless; but
we have no reason to suppose that it is annihilated, or
cannot be re-produced in its pristine state. Water,
though perfectly dissolved, and to appearance deprived
of existence in the air, may yet be precipitated from it,
and pour down upon us in deluges. What happens in
one case may happen in another. The infectious matter,
dissolved in the air, may by some natural cause be
precipitated from it, overshadowing whole regions, and,
if it be not powerful enough to produce the epidemic of
itself, may certainly predispose to it in such a degree,
that the slightest additional cause will bring it on.
Something indeed of this kind would seem really to
be the case, otherwise we cannot well conceive why there
should be such a distinction of diseases. Thus the infection
of the small-pox is the same all over the world.
The variolous matter will never produce the measles in
any country, nor will the typhus produce a pleurisy.
The plague manifests itself to be the same distemper in
all its various degrees of malignity, though even this
dreadful disease is sometimes so mild that it does not
confine the patient to his bed. There must therefore be
some certain constitution in the nature of the cause
which produces such and such diseases, as certainly as in
the seed of particular vegetables, which gives to each its
proper appearance and shape. The cause of the disease
so modified we may call, with Dr. Cullen, its specific
contagion.
Having thus treated so largely upon contagion of
different kinds, it now remains to consider the objections
that have been made to the doctrine altogether. It is
indeed surprising that in so great a length of time, after
the world hath so often and so dreadfully suffered from
the violence of plagues, the simple fact, whether it be
infectious or not, should not have been determined:
nay, that it should still be questioned by physicians of
no mean reputation whether such a thing as contagion
or infection can possibly exist. Dr. Mosely in his treatise
on tropical diseases treats the whole doctrine of contagion
with the utmost contempt; calling it “a field for
speculation, which has long amused the pedantry of
the schools, and should never be entered into by practical
writers.” Notwithstanding this, however, he
doth enter into it, and with such bad success, that in the
very first paragraph he is obliged to derive the cause of
diseases from the stars! “There are some diseases we
know, (says he) which follow the changes of the atmosphere;
but there are others which make their
revolutions, and visit the earth, at uncertain periods;
for which we can trace no cause, depending on combinations,
in which, perhaps, the influence of the planets
may have some share.” Here we have a still wider
field for speculation than even the schools have given us;
for the Doctor ought to remember that the influence of
a planet, producing a disease, is as truly contagion as
the effluvia of a dunghill; and if we have a wide field
to traverse when tracing it through the earth, we have
one infinitely more extensive in pursuing it through the
heavens. But we may be assured that planetary influence
does not produce diseases; for, if it did, they would
in all times of pestilence overspread the face of the earth,
as the influence of the planets, if they have any, certainly
does.
The arguments used by this author against terrestrial
contagion are,
1. “It has often happened that hundreds of men in
a camp have been seized with the dysentery, almost
at the same time, after one shower of rain, &c. People
under similar circumstances must be subject to
similar diseases: and yet it often happens that dysentery
begins with a few people, and spreads itself by
degrees until a multitude are affected.”
This argument rather militates against himself; for,
if dysentery or any other disease was occasioned by an
evident general cause operating upon persons in similar
circumstances, all of them ought to be taken ill at once;
but Dr. Mosely owns that they frequently are not.
There must, of consequence, be something less evident
which determines the disease to particular persons, while
the general cause operates equally upon all. This less
evident cause we call contagion.
2. “It is incredible that the smelling a little human
blood, that had stood some months in a phial, gave
the man a dysentery mentioned by Pringle; or that the
person Forestus speaks of got the plague by only putting
his hand into an old trunk; or that the shaking an
old feather-bed, which had lain by seven years, raised
a plague at Wratislau, which destroyed five thousand
persons in twelve weeks, as related by Alexander Benedictus,
&c.—Such things may be true, but, when
probability is shaken, reason always inclines to skepticism.”
Here our author most evidently contradicts himself;
for in the beginning of the paragraph he tells us that
the things related are incredible, and in the end of it, that
they may be true. The argument, if it may be so called,
is mere assertion. It is incredible that the smell of putrid
human blood in a vial should produce the dysentery.
Why should this be more incredible than that smelling
to a charged vial should ensure an electric shock to the
person who did so? This is entirely a question respecting
a matter of fact, not of speculation. The same is the
case with the rest. It is not more incredible that, if the
infection of the plague was in a trunk, a man should get
the plague by putting his hand in it, than that he should
be burnt if he put his hand into a trunk full of hot ashes.
Before the Doctor decided in such a positive manner,
he ought to have proved that no infection could be
contained in a trunk; but this, though the very point
in question, he takes for granted, first telling us that the
contrary is incredible, and then that it may be true!
3. “We observe in camps and hospitals, that those
people whose dirty employments subject them in a particular
manner to a depravation of their habits, seldom
escape the present epidemic; and this gives rise to the
vulgar expression, and very incorrect notion, of catching
the disease. And we observe that others from the
slightest deviation from regularity lose the power by
which the body resists diseases, and they are also attacked.
But these attacks are not to be attributed to
infection: for those people who keep the vital and
animal powers in uniform confederacy, by temperance
and calmness of mind (for fear, by lowering the vital
energy, subjects the body to disease) nourishing diet,
proper clothing and cleanliness, and keeping a free and
regular passage for all excretions, are proof against the
assaults of foul and pestilential air. Such people seldom
suffer even by the plague itself: while all around
them perish.”
The first sentence of the above paragraph is so obscurely
worded, that it is difficult to know the author’s
meaning. I know not of any lawful employment so dirty
that it necessarily subjects the person who practises it to
a depravation of habit. The next ascribes every thing
to intemperance and fear; from which, it seems, we are
to infer that none but drunkards, cowards, and dirty,
naked ragamuffins, are ever seized with epidemic diseases.
But of this we are able to bring a direct disproof. I suppose
Dr. Mosely will not say that the celebrated Prince
Eugene of Savoy was either a coward or a drunkard;
that he had a dirty employment, wanted proper food or
clothes, or was deficient in personal cleanliness; yet,
when in the marshy parts of Hungary, he was in danger
of death from an epidemic dysentery, notwithstanding
that he was so careful in respect of diet, that he had
pure water brought him every day, probably from a
considerable distance. How came he to be affected by
the distemper under such circumstances, while Count
Boneval, though as an inferior officer he probably enjoyed
fewer advantages, remained free from it, taking only
a small quantity of Peruvian bark daily? It is uncertain
whether the bark did really preserve him or not; but
the case of Prince Eugene plainly shows that sobriety,
temperance, valour and cleanliness are not sufficient to
ward off an epidemic disease, if people come in the way
of infection.
4. “It should follow, if contagion were supported by
infected bodies, that no person should ever escape
infection (as at Oxford assizes in 157787) who was
within the sphere of its action; and that those who
were entirely secluded from it, and free from all contiguity
to infected people, or substances, as the collegers
were in the town of Cambridge, when the plague
was last in England, should be exempt from it.
“But, in opposition to this, Rhazes lived 120 years,
an often practised in plagues. Hodges remained in
town, and attended the sick, during the great plague
in 1665. Kaye was in the midst of practice in the
sweating sickness in 1551, without any inconveniency.
Procopius informs us, that during a terrible plague at
Constantinople, in 543, which almost destroyed the
whole city, no physician nor other person got the
plague by attending, dressing or touching the sick.
Yet most of the Capuchins, the Jesuits, the Recollets,
the Observantines, the Barefooted Carmelites, the
Reformed Augustines, all the Grand Carmelites, the
Grand Trinitarians, the Reformed Trinitarians, the
Monks of Loretto, of Mercy, the Dominicans, and
Grand Augustines, who kept themselves secluded in
their several convents, and took every precaution to
avoid the plague, while it raged at Marseilles, perished
by it.
“There are no epidemical nor contagious diseases
that attack every person who breathes the same air,
or that is in contact with the infection, else whole
regions would be depopulated. The habit must be
graduated, or adapted, for the reception of a disease.
In some constitutions of body the access is easy, in
some difficult, in others impossible. But where the
revelation of this mystery is to be found, none can tell.”
In this, which our author seems to have designed as
his grand argument, it is plain that the deficiency is as
great as in any of the rest. If we suppose the plague, or
any other epidemic disease, to arise from some general
cause, let that cause be contagion or any thing else, it
ought to operate upon all who come within its sphere of
action, as Dr. Mosely observes of infection. If experience
shows that it does not, the argument will hold equally
against a constitution of the atmosphere, putrid effluvia,
heat, cold, or any thing else; and in fact the Doctor
fairly gives up the point at last, by resolving the whole
into an unrevealed mystery. With regard to what he
says about the plague at Marseilles getting into the convents,
of which he presents us with such a catalogue, it is
impossible to know what precautions were used, and we
are assured that in Turky it is thought necessary for the
Europeans not only to guard against a communication
with their own species, but some of the brute creation
also. Cats particularly are dreaded so much, that a
general massacre of them commences among those who
use precautions, the favourites of that species must be
sent to a distance, and M. Volney mentions two merchants
who had shut up their houses, and yet had the
plague imported by a cat. In short, considering that
infection is supposed to be altogether invisible and imperceptible,
it is impossible to say how it may be conveyed,
or to what extent it may occasionally act when once
brought into a country. Dr. Fordyce is of opinion that
the distance at which infection may act depends on the
disposition of the air at the time; and he observes, that
a difference in this respect is observable in the odoriferous
effluvia of vegetables. “If the air be loaded with moisture,
they reach to a much greater distance. Vapour
arising from a field of beans, for instance, or a putrid
ditch, is sensible to the nostrils at a greater distance
if the air is moist.” He observes indeed that this
has never been verified with regard to infection; but as
it is evidently the case with putrid effluvia, which very
often accompany infection, we may reasonably conclude
that it is the case with the latter also.
Let us next take a view of what is advanced by the
authors of The Science of Life upon this subject.
Mr. McLean, who puts his name to this part, informs us
of his conviction “that no general disease, which affects
a person more than once during life, can ever be communicated
by contagion;” and he defines contagion
“a specific matter, generated in a person affected with
disease, and capable of communicating that particular
disease, with or without contact, to another.” It
would here be no improper question, by what means he
comes to know that a contagious disease can affect a
person only once. But even this question is unnecessary.
Dr. Guthrie gives an account of a gentleman who
had the courage to inoculate himself for the plague, in
consequence of which he had the disease with the concomitant
symptoms of buboes, &c. Here then we see
the plague communicated by “a specific matter generated
in a person affected” with the same disease, i. e.
by contagion, according to Mr. McLean’s own definition.
The dispute therefore might stop, as this fact
seems to be decisive on the subject; but as he has at
great length insisted upon the argument last quoted from
Dr. Mosely, it seems necessary to follow him a little farther.
“If a person (says our author) be affected with any
disease, it will necessarily be communicated to every
other person who comes within the infectious distance,
and is not at the same time labouring under some disease
higher in degree.” This proceeds upon a supposition
that his theory is absolutely perfect and infallible; which,
however plain it may appear to himself, will not probably
be admitted by others without some proof. Indeed
he himself afterwards adduces some facts which decisively
overthrow it. “A child (says he) here and there is
exempted from small-pox, even though exposed to
its contagion.” How comes this to pass? The disease,
we are told, is contagious, the child is exposed to the contagion,
and yet is not affected. In all such cases it would
be ridiculous to suppose the subjects labouring under a
disease higher in degree than the contagion could produce.
In numbers of instances of this kind the children
were evidently in good health, and yet would perhaps be
seized at an after period when no more exposed to contagion
than they had been at first.
“Small-pox, measles, and other general diseases, which
occur only once during life, never disappear, until the
whole of those who have been within the infectious
distance, and were not at the time labouring under
some disease higher in degree, have received the infection.
As these diseases are very mild, children sometimes
resist the power of contagion from the superior
force of some other diseases, although they may be so
slight as to escape common observation.”
In this paragraph we have the favourite maxim of our
author repeated, twice indeed, without a single fact to
support it. Instead of this we find hypothesis heaped
upon hypothesis, as the giants are said to have heaped
mountains upon one another in order to get up to heaven.
He first supposes that the infection of the small-pox
seizes on the whole of those on whom it falls. The
exceptions to this maxim he explains by another supposition,
viz. that the contagion of the small-pox is counteracted
by another disease. The second hypothesis is
supported by a third, and that a very extraordinary one,
that the small-pox (a disease which has destroyed innumerable
multitudes) is very mild; and this third by a
fourth, that the diseases which counteracted the contagion
were so slight as to escape common observation. It
was incumbent on Mr. McLean to have pointed out
some of those diseases, and to have informed us how they
came to counteract this contagion. But it is needless to
argue with one who writes so extravagantly. Far from
the mode of reasoning followed by Dr. Fordyce, who
decided from the majority of facts, our author determines
every thing by his own preconceived opinions.
“That the power which occasioned disease at the Oxford
assizes (says he) was not contagious matter, is
proved by its producing diarrhœa in some, while it
produced fevers in others.” But, if it was not contagious
matter, what kind of matter was it? Or how
comes our author to know that those who were affected
by the diarrhœa were not likewise affected by fever?
How many fevers are attended by diarrhœa, or how many
cease when diarrhœa comes on! It would have been
equally conclusive to say that the matter was not contagious,
because some died and some recovered.
I shall only take notice of one assertion more, it being
both tedious and unnecessary to follow him through the
whole. “From every record of epidemic and pestilential
diseases, it would appear, that they have their stated
periods of recurrence; that these periods are such
months as are most remarkable for vicissitudes of the
atmosphere; that they become general only in those
years in which these vicissitudes are extreme; that
they do not occur in seasons when the heats or colds,
however intense, are equable; nor in years when the
state of the atmosphere is tempered throughout; and
that they uniformly cease with the establishment of
an equable state of the atmosphere, whether the weather
be cold or hot. . . . In Aleppo, according to Dr.
Russel, the Europeans regularly shut themselves up in
their houses every year, at some period between April
and July; and the rich natives begin to adopt the
same plan, &c. . . . From this fact it appears, that
the plague occurs at Aleppo, in a state more or less
mild, almost annually, and that it commences and ceases
at certain known periods. But it has been remarked
that, in its most severe state, this disease recurs only at
periods of ten years, or thereabouts: a regularity which
cannot, upon any known principle, be attributed to a
power of such casual application as contagious matter.”
In the beginning of this paragraph our author makes
a bold appeal to every record of epidemic and pestilential
disorders; but here we may ask, Has he consulted
every record of these disorders? That he has not, we may
readily believe; but even those which are hinted at seem
either to have been very inaccurately consulted, or wilfully
misrepresented. To evince this I subjoin the following
abstract of what Dr. Alexander Russel says of
the plague in general, with the annotations of his brother,
Dr. Patrick, taken from Russel’s Natural History
of Aleppo.
The inhabitants of Aleppo suppose that the plague
visits them once in ten years, and that it is always imported;
and the most severe plagues are thought by
some to come from Damascus, while others contend
that they come from the northward. Dr. Alexander
Russel thinks this popular opinion of the return of the
plague not altogether unfounded; and he thinks it also
probable that it never invades Aleppo without having
previously attacked either Damascus or Khillis, Aintab,
Marash or Uufa. He thinks that its appearance always
is in one of the maritime towns of Syria; if in Sidon,
Byroot or Tripoli, Damascus is commonly the channel
by which it reaches Aleppo; but, if it shows itself first
at Scanderoon or Byass, its approach is by the way of
Khillis or Aintab.
On this Dr. Patrick Russel observes, that the account
of Aleppo being visited only once in ten or twelve years
is confirmed by a letter from an English gentleman, in
1719, who had resided there for 30 years. The dates
of the plagues which Dr. Patrick had procured were,
1719, 1729 and 1733. Another began in 1742, and
terminated in 1744; from which time there was no
return till 1757 or 1758, when it continued at Aleppo
till 1762, and did not entirely quit the country till 1764.
The plague of 1719 was said to come from the northward,
but this appeared to want confirmation; but all
accounts agree that it raged at Tripoli, Sidon, &c. two
months before it appeared in Aleppo. Egypt was ravaged
by the plague in 1728, as was also Byass and the
neighbouring parts in the same summer; and next year
it appeared at Aleppo. In 1732 it raged at Sidon, Tripoli
and Damascus; next year it seized Aleppo.
Dr. Alexander goes on to inform us, that the disease
never spreads much in winter. It advances with the
spring, comes to its height in June, declines in July,
and terminates in August. “None (he says) are ever
seized with in September and October, not even in the
plague of 1742, which returned three years successively;”
but Dr. Patrick says that this was not confirmed by his
experience in 1760, though he owns that the distemper
declines remarkably at that period; and the natives are
greatly inclined to have it believed that the distemper
has totally ceased, and to deceive the Europeans in
this respect. The times at which the Europeans shut
up and come out of their confinement show only the
increase or decrease of the disease, but not its beginning
or ending. The plague of 1719 made terrible havoc.
Europeans then shut up about the middle of March,
and kept confined till the middle of July. In 1729
they did not shut up till the middle of May, and were
not confined above a month, the number of sick being
small. In 1733 they were confined from the middle of
March to the middle of July, but the distemper was
less violent than in 1719. In 1742 the time of confinement
much as in 1729. In 1743 shut up April 11,
and opened the middle of July. The plague violent,
but less so than in 1733. In 1744 few shut up, the
number of sick being inconsiderable. In 1760 they
shut up on the 30th of June, and continued about a
month. In 1761 shut up May 28, rode out Aug. 1,
and opened completely the 10th of that month. In
1762 they were confined from the last week in May to
the first of August. From 1762 to 1787, a larger period
than usual, the city was free from the plague. In
1787 it broke out among the Jews in the month of
April, increased in May, raged violently in June, and
terminated in July.
From these accounts it appears, as Dr. Alexander
Russel informs us, that the plague of one year differs
remarkably from that of another; but he says, that,
at Aleppo, it is never attended with such scenes of
horror as have been known in European countries; for
which Dr. Patrick assigns the following reasons: 1. The
markets are constantly supplied with provisions. 2. The
dread of the contagion is much less. 3. The sick are less
liable to be deserted by their attendants (but this, according
to his own observation, is not always the case) and
4. The regular, speedy interment of the dead prevents a
spectacle far from uncommon in the European plagues,
and which of all others is the most shocking to humanity.
“Extreme heat (says Dr. Alexander) seems to check
the progress of the distemper. July is a hotter month
than June, and the season wherein the plague ceases
at Aleppo is that in which the heats are most excessive.”
His experience did not confirm a popular
opinion at Aleppo, and which has likewise been adopted
by many medical writers, that the moon has any influence
on the distemper. To have had the distemper
once does not secure a person against future attacks.
Numbers of people who were alive when he left Aleppo
had it twice or oftener; and he had instances of some
being infected thrice in one season. Dr. Patrick Russel
has observations to the same purpose.
From this it appears, that the popular opinion at Aleppo,
which Mr. McLean wishes to establish as a certainty,
is by no means so well founded that we can build any
theory upon it. The misfortune is, that, wherever a
theory is built upon any thing said to be constant and
invariable, a single failure overturns the whole. Now,
in the dates of plagues above mentioned, the variations
are so great that it is impossible to draw any certain
conclusion from them. In the first three instances of
1719, 1729 and 1733 there is indeed a coincidence of
the first two, but the last falls short by no less than six
years. What then does Mr. McLean mean by his “ten
years, or thereabouts?” Can thereabouts imply a difference
of more than half? The English gentleman’s testimony
who resided 30 years in that country could extend
no further than to three plagues, and even these are not
mentioned. The fourth instance in 1742 is deficient in
one year; the fifth in 1757 or 1758 exceeds by three or
four years, and the sixth from 1762 to 1787 by no less
than fifteen years.
An anonymous writer in a Scots periodical publication
entitled “The Bee,” has partly adopted the above
opinion, but adds others for which he has not thought
proper to adduce any authority. “It visits most parts of
Asia once in ten or twelve years, and carries off an
eighth or tenth of the inhabitants. There have been
plagues which have carried off one fourth of the inhabitants.
The farther east you go, the less frequent it
is—every 20th, 40th, and, even at Bassorah, every
90th year; but then this scourge is most dreadful.
The last plague at Bassorah, which had not visited the
city for 96 years, carried of more than nine tenths of
the inhabitants.”88 It is astonishing that people will
write in such a manner as to subject themselves to endless
criticism on account of their inconsistency. The plague,
this writer says, visits most parts of Asia once every ten
or twelve years, and yet it goes no farther east than Bassorah;
a space scarce equivalent to the twentieth part of
Asia! Even in this small space, it varies from ten or
twelve, to twenty, forty, or even ninety years; and, to
complete the whole, instead of giving any instance of the
periodical return of the plague at an interval of ninety
years, we have one of its disappearance for ninety-six
years!
From all this it is evident, that no dependence can be
placed on such vague accounts with regard to the periodical
returns of the plague. Even the time of shutting
up the houses in Aleppo is not accurately related, for,
from the above abstract it is plain, that they are sometimes
shut up in March; while Mr. McLean would
have us to believe that it is always between April and
July. It is needless to wade through a jumble of unsupported
assertions, which, being backed by no evidence,
fall to the ground of themselves. “I will venture to assert
(says he) that no person in perfect health ever
was or can be exposed to the power of contagion, without
receiving the specific disease which that contagion
produces; excepting in small-pox, measles, &c.
when the person has previously had the disease.”—How
comes he to know all this? Or, though our author
ventures to assert, must we of necessity venture to
believe? When he ascribes the origin of epidemics, and
the plague itself, to the vicissitudes of the atmosphere,
not a single fact is adduced in support of his hypothesis.
One very strange proof indeed he brings from Dr. Rush,
viz. that the latter had been informed by a gentleman
who resided in tropical countries, that, in the month of
July, several weeks before the yellow fever became general,
he had observed a peculiar and universal sallowness
of complexion in the countenances of the people of Philadelphia,
such as he had seen in those of the more
southern countries before the appearance of bilious fevers
in them. Surely it is a very strange mode of argument
to tell us of the colour of people’s countenances instead
of the states or vicissitudes of the atmosphere, which we
are made to believe were the causes of that change.
Another quotation is made from the same author in
which a warm, dry, stagnating air is conjectured to have
been the cause of diseases; but he does not even quote
Dr. Rush saying that it was the cause of yellow fever,
much less of all epidemic diseases. Besides, to say that
any thing is occasioned by a state, or vicissitude of the atmosphere,
is such a vague mode of expression, that it
must either mean nothing, or be contradictory to itself.
A state of the atmosphere we must suppose to mean that
it continues for some time either to be wet or dry; a vicissitude,
when it changes from one to the other. If an
epidemic then is produced by a state, it cannot also be
produced by a vicissitude, of the atmosphere: or, if some
epidemics are produced by states, and others by vicissitudes,
we ought to be informed which produce one kind,
and which another. But throughout the whole of this
dissertation we have neither distinctness nor regularity,
nor indeed any thing but assertion, supported only by an
imaginary theory.
Dismissing at length therefore these conjectural theories,
let us endeavour to deduce from certain and undoubted
facts the connexion between the state of the
body, and the operations upon it of other causes, invisible
indeed to our eyes, but discoverable by our rational
faculties, and in some measure capable of being made
the objects of our senses also.
1. From the account given of the structure of the
human body, it undeniably follows, and has already been
observed, that all parts of it are so connected together,
that none can suffer any very grievous injury without affecting
all the rest.
2. The life of man depends immediately on the air.
From this element the blood receives heat and a vital
spirit diffusing itself from the blood along the nerves,
and thence expended in the operations of life and sensation.
3. From undoubted experiments89 it appears, that
this vital spirit possesses in a great degree the properties
of electricity, insomuch that many suppose them to be
the same. This is indeed denied by the celebrated
anatomist, Dr. Monro, but he allows that the nervous
fluid is similar to electricity, and it is certain that the
electrical fluid can affect it in such a manner that we
may reasonably believe them to be the same.
4. The air acts upon the blood by the latent heat it
contains. The air itself is composed of something
volatilised by heat. In some cases this is evidently a
terrestrial substance, as in that of inflammable air, or
hydrogen, which is formed of charcoal volatilised by
heat, with the addition of a little water. In the case of
oxygen, or dephlogisticated air, the combination seems
to be the matter of heat (which I shall hereafter distinguish
by the name of the ethereal fluid) with water deprived
of its carbonic principle. This coincides with
the opinion of Dr. Priestley, who says that the basis of
dephlogisticated air seems to be dephlogisticated water.
But, let the basis be what it will, the ethereal fluid which
volatilises it is the agent; the basis is entirely passive, and
only modifies or restrains the action of the other fluid,
so that it does not exert itself except in particular cases.
Fixed air, or carbonic acid, is composed of the base of
oxygen united with a certain portion of carbon, and the
whole volatilised by the ethereal fluid. Phlogisticated
air, azote, or septon, according to Dr. Priestley, consists
of the basis of dephlogisticated air along with a certain
proportion of carbon different from that which produces
fixed air, volatilised by the same agent;90 and so we
may determine concerning every other species of air.
5. In certain cases the ethereal fluid quits those substances
with which it is united: the air is then decomposed,
the substance into which the other fluid enters is
heated, or rendered more fluid than before (perhaps
both) while the basis either unites itself to the moisture
of the lungs, or is thrown out by the breath. Whether
in any case the basis can pervade the membranes, and
thus mix itself with the blood, notwithstanding the
positive assertions of Dr. Girtanner and others, is very
doubtful, and does not admit of any positive proof.
6. The blood, being a fluid, must be subject to the
same laws with other fluids. A certain quantity of
latent heat must be contained in it, in order to give the
degree of fluidity naturally belonging to it. If this
quantity be augmented, the fluidity will be augmented,
and the blood will become thinner; if it be diminished,
the contrary will take place; and if we suppose a great
proportion of this latent heat to be abstracted, it is not
unreasonable to suppose that something like a congelation
may take place, and the blood be changed into a solid
substance of such a nature as cannot any more be made
to resume its former qualities.
7. By augmenting the sensible heat, the blood is affected
in the same manner as any other fluid; it suffers
expansion, by which the vessels are dilated in proportion,
and, if this expansion and dilation be carried to a certain
length, a rupture of many of the small vessels, and
apoplexy, or some other grievous disease, may ensue.
8. By breathing certain kinds of air, the fluidity, heat
and expansion of the blood, and of consequence the dilation
of the blood-vessels, are affected. Thus, when a
person breathes a quantity of the fume of charcoal,
containing much fixed air, he feels himself affected with
pain and a sensation of fulness in his head; he becomes
sleepy, and, if the quantity be sufficiently great, he falls
into an apoplexy, and dies. From dissections it appears
that such as die in this manner have the capillary vessels
greatly distended, and even ruptured; the heat of the
body is vastly augmented, and even continues some time
after death. Hence it is evident, that, by breathing
this kind of air, too much sensible heat is conveyed to
the blood. In like manner when we breathe the steam of
water, if any quantity of that steam be condensed in the
lungs, the whole quantity of latent heat contained in
that steam discharges itself upon the lungs, and increases
the sensible heat of the body; and from this we may
learn why on some occasions our sensations should so ill
correspond with the thermometer, and why a warm air
almost saturated with moisture should always appear
much hotter than a dry one, though the thermometer
stand at an equal height in both. Oxygen air seems
to convey to the blood a much larger quantity of
what we have called vital spirit, than any other kind.
Whether this vital spirit be the same with the latent
heat of the blood, we know not; but, as this kind of
air is evidently capable of supplying the blood both with
latent and sensible heat, it seems most probable, that,
by breathing a considerable proportion of it, both these
kinds of heat, as well as the vital spirit itself, will be
augmented. In this case, wherever the air naturally
contains a larger quantity of oxygen than usual, the
blood ought to be mere fluid, as well as warmer, than
usual, provided there be no evident cause why it should
be otherwise. Accordingly in warm climates it is always
found that the blood is thinner and more fluid
than in such as are colder; but at the same time the
temperature of the body is colder than in other countries.
Zimmerman tells us, that, “at Curassau, Europeans
gradually lose their fresh colour and vivacity:
their natural heat even becomes three or four degrees
less than it was at their arrival.” The reason of this
last, however, is evidently the excessive perspiration,
which is more than sufficient to carry off the superabundant
quantity of sensible heat thrown into the body,
either by the rays of the sun, or by the superior quantity
of oxygen naturally existing in the atmosphere; for it
is now found, contrary to the opinions hitherto received,
that in the warmer climates the atmosphere contains a
larger proportion of oxygen than in the more temperate.91
From this discovery it appears, that, whatever may be
the cause of the frequency and violence of epidemics in
warm climates, it is not the want of oxygen. Nay, we
should rather be tempted to think that they were produced
by too great an abundance of it; and this the more
especially when we know that animals confined in oxygen
air are supposed to die of a burning fever; and it is likewise
known that this kind of air is prejudicial to consumptive
people, and even brings on the disease on those
who had it not before. From the experiments mentioned
in the note, it seems probable that there are but few
even of swampy places in hot climates, where oxygen
does not predominate; and in these the heat thrown into
the blood must still be augmented by that produced
from the quantity of vapour decomposed or condensed
in the lungs, which, as the condensation depends upon
unknown circumstances, can never be foreseen, or ever
prevented, but by a removal from the place.
With regard to other kinds of air, such as inflammable,
phlogisticated air, &c. experiments are yet wanting
to determine their effects upon people who breathe them
habitually. The proportion in which they occasionally
exist in the atmosphere on particular occasions has not
been ascertained, and from the experiment made by Dr.
Priestley with offensive air taken from a manufactory,
as well as from Dr. Chisholm just mentioned, the probability
is, that, even in the most offensive places, the proportion
of azote is by no means so great to the oxygen
that we could suppose the excess capable of producing a
disorder of any consequence, much less a violent epidemic.
Fixed air is always produced in the putrefactive
process, and from its quality above mentioned of rarefying
and heating the blood, might reasonably be supposed
to have some share in producing epidemics, were it not
that this kind of air is so readily absorbed by water, as
well as a number of other substances, that, except at the
very moment of emission, we can scarce suppose it to
have any considerable effect.
Mr. Watt in a letter to Dr. Beddoes gives an account
of a kind of air, seemingly more noxious than any yet
discovered, which he produced by distillation from flesh
and from wool. The effects upon himself were so disagreeable
that he determined to make no more such experiments,
lest he should to his own hurt discover a
mode of producing some grievous disease. But we cannot,
from an artificial air of this kind, argue to a natural
one; as the one produced by Mr. Watt was totally different
from any species of air naturally known. All that
we can say is, that, as far as we can trace the connexion
between our bodies and the different kinds of air which
may be breathed, the latter act chiefly by the heat they
contain, and which they impart to the body in various
proportions; by which means the latent or sensible heat
of the blood, and consequently of the whole body, may
be occasionally augmented or diminished. Thus the
body may be considerably altered in its constitution,
and rendered more liable to diseases than it was before;
but still it is found that diseases continue to appear at
uncertain intervals, though all the causes we are able to
discover, or at least all that are constantly evident to our
senses, continue to operate without intermission. Though
the obvious qualities of air and climate therefore may
predispose to an epidemic, we cannot affirm any thing
farther: the direct cause is always different, and hath
hitherto so much eluded our researches, that we can have
little hope of discovering it, except by reasoning from
facts less obscure.
8. In all the operations of nature which we have access
to investigate, the action of electricity is so much
concerned, that we can scarce suppose it to be wanting
in any of them. That it is concerned in preserving
the health of the human body is likewise certain,
if it be the fluid which acts in the nerves, as most probably
it is. But whatever preserves health will also
bring on disease, if it be applied to that purpose; and
we have already seen that this fluid is capable of bringing
on the most dreadful symptoms, viz. mortification
in its highest stage, fever, convulsions, bilious discharges,
lethargy, &c. If it be capable of producing all these,
can we say that it is not capable of producing those of
an inferior kind, or of varying diseases and symptoms
without end, according to the immense diversity of its
action? It may be said that this disease was occasioned
by a violent stroke of electricity, similar to lightning;
but how many people have declared, that, in the
beginning of some violent epidemics, they have felt a
sudden stroke at the time of seizure! Dr. Hodges
mentions this in the plague of 1665 at London, but
treats the accounts as effects of a distempered imagination.
Procopius relates the same of the plague in his
time, viz. that many of the diseased felt a stroke. It
is true that they said such strokes were given by spirits
in human shape, in which we know they must have
been deceived; but, though they were mistaken in
supposing that they had been struck by a spirit, it does
not from thence follow that they felt no stroke at all.
The people mentioned by Dr. Hodges did not say that
they were struck by a spirit, yet he treats their accounts
with as great contempt as though they had. Where
people have no interest in deceiving, we ought certainly
to look with a favourable eye upon their testimony; for,
even although some part of it should be incredible, we
have still reason to believe that there is some foundation
for what they say. Thus, the poor sailor, so much frightened
at the sight of a large bat in New Holland, was
certainly mistaken in saying that he had seen the devil;
he was even mistaken in saying that he had horns;92 but
from all this it would have been doing him great injustice
to say that he had seen nothing. In like manner, when
numbers of people in Procopius’s time said that they
were struck by spirits, when we find others in Dr. Hodges’s
time saying that they were struck by some invisible
agent, when we know that electricity can strike in an
invisible manner, it certainly is more reasonable to conclude
that violent diseases sometimes do begin by an electric
stroke, than that all who said they were struck in
this manner were madmen or liars.
It may now again be asked, if the plague, or violent
epidemics, be produced by electric strokes, why are they
not much more frequently felt, or by what are those
milder diseases produced which are not accompanied by
any sensible stroke? Here we can be at no loss to say,
that whatever produces the highest disease, may also produce
the lowest. But, besides this argument, we have
positive evidence that commotions in the electric fluid
will not only produce sickness, but very extraordinary
and seemingly miraculous effects upon inanimate bodies.
It has frequently been remarked that people are sick
during the time of earthquakes, when the electric matter
is in violent agitation. This has been accounted
for from the motion of the earth, as the motion of a
ship produces sea-sickness. But Dr. Hillary mentions
a slight earthquake in Barbadoes where people were affected
with sickness and vomiting for some hours after
the phenomenon had ceased altogether; which undoubtedly
shows, that a certain state of this fluid will disorder
the human body, independent of every other circumstance,
either of the heat or cold of the atmosphere, or
the oxygen, hydrogen or azote contained in it. Again,
we find that a certain state of the electric matter is not
only capable of producing very extraordinary effects by
itself, but also of communicating a power to the human
body to do the same. A good number of years ago, a
powder-mill near London was blown up. The explosion,
as might be expected, was violent and tremendous;
but the most remarkable circumstance was, that
the electric matter, for a great way round, was thrown
into unusual, though invisible, commotions, which discovered
themselves by the rattling and breaking of china
dishes though sitting apparently undisturbed upon
their shelves. This phenomenon did not suddenly cease,
and, during the time of it, some people appeared to be
infected by an electric contagion; the power of breaking
china seemed to reside in their bodies, so that if they approached
or touched this kind of ware, it would instantly
fly to pieces. Accounts of this extraordinary circumstance
were published in many of the periodical works
of the time, particularly in Dodsley’s Annual Register;
and the fact seems to be established beyond controversy.
It proves that what has been advanced by Dr. Priestley
concerning electrical operations, on a small scale, holds
good also on a large one, viz. that the fluid, when once
set in motion, is not easily quieted. It establishes the
fact, also, that by great explosions of gun-powder the
electric matter is violently agitated; and the consequence
of these agitations we cannot know. It may be
said, indeed, that in the operations of nature the electric
matter is often violently moved without any sickness taking
place; neither in fact did any ensue at the time the
powder-mill in question was blown up. But it must be
remembered, that, in the ordinary course of nature, if the
electric matter is moved, a receptacle is also provided
for it. In a thunder-storm, where immense discharges
of electricity are made from one cloud, there is another
cloud of an electricity opposite to the former ready to
receive them, or if not, the earth itself is frequently struck.
In eruptions of volcanoes, the smoke receives the electricity
discharged, and becomes charged with lightning of
a more dangerous kind than that of ordinary thunderstorms;
and Sir William Hamilton relates, that in the
great eruption of Vesuvius, in 1794, lightning of this
kind proceeded from the smoke for no less a space than
seventeen days. But in artificial commotions of this fluid,
where nature has not provided any receptacle, the
phenomena must be quite different; and though we
may with safety to ourselves interfere with the operations
of fire and electricity to a certain degree, yet we may at
last rouse these terrible elements into such action as will
prove fatal to great numbers. Hence possibly may arise
in part some of those sicknesses which take place after
battles, in violent sieges, &c. An instance of this is
said to have happened at Valenciennes, when last besieged
by the Duke of York. A disease prevailed chiefly
among women, children, and persons of a weak constitution;
great numbers of whom died so suddenly that
it was at first thought to be a plague, until it was found
not to be infectious. The blood was found greatly dissolved,
and the physicians ascribed it to the monstrous
bombardment and cannonading which took place during
the siege. Such was the account published in some of
the newspapers of the time, and from the subsequent
considerations it will not seem improbable that such
things may take place.
From the experiments of Mr. Bennet (an English gentleman
who has made several discoveries in electricity)
it appears, that we can neither brush a piece of chalk,
open or shut a book, or do several of the most trifling
actions, without agitating this subtile fluid in a perceptible
manner. It is well known that in some cases we
cannot stroke a cat’s back without making the electric
matter visible, and in some positions, by putting our
fingers near the ears of the animal, very pungent sparks
will be received. If then we can neither open or shut a
book, if we cannot stroke a cat’s back, or approach a
finger to her ear, without agitating the electric fluid, is
it reasonably to think we could burn a book, or kill a
cat, without doing the same? Certainly it is not. If
we cannot burn a book or kill a cat without affecting
this fluid, it cannot be supposed that we can burn a
house or kill a man without producing a still greater
commotion; and in proportion to the extent of our devastations,
and the multitude of our massacres, the invisible
agitation of this element must become still greater
and greater. In all these transactions it must be remembered
that the fluid is forced out of its natural mode of
action; for electric matter is made for the preservation, not
the destruction, of life: but if, by long continued and extensive
application of its power to a contrary purpose, we
in some measure pervert its action, no wonder that we
then feel the consequences of our own proceedings by its
partly turning its power against the human race altogether.
Again, the human body is not made for the habitation
of an infernal spirit, but for one of a quite different
character. The boisterous passions of fury, discord and
hatred ought never to disturb the mind, which is made
for the habitation of endless peace and joy. The tumultuous
passions are enemies to health; and this is so well
known to physicians that they are very careful to prevent
their patients from being any way ruffled or disturbed by
violent passions. It is true these passions act upon the
rational soul, which we may suppose to be distinct from
that merely animal spirit, probably no other than the
electric fluid, which runs along the nerves; but experience
shows that each of these can act upon the other; a
disorder in the body, particularly in the nervous system,
will sometimes disturb the rational soul in such a manner
as almost entirely to deprive it of all its faculties;
while on the other hand a violent commotion in the
rational soul may at once extinguish all the powers of
life, as has already been shown from Zimmerman. Now,
let any one consider what must be the sensations of those
who engage in war. Whatever pity or humanity may
be pretended, it is evident that in the day of battle all
these sensations must give way to horror and fury on the
part of the conquerors, and terror and dismay on that
of the vanquished. That these passions never do entirely
subside, is evident from the treatment of conquered
countries and conquered people. When Jenghiz Khan
beheaded his prisoners by hundreds of thousands, when
Tamerlane pounded them in mortars, when Khouli Khan
caused those who offended him to be carried from place to
place, and a piece of flesh to be cut from their bodies at
each stage, what must have been the sensations of these
miscreants, and those whom they employed in such horrid
scenes? On the other hand, what must be the sensations
of those who see their dearest relations torn from them
and slaughtered or treated even worse than if they were;
themselves driven from their peaceable abodes to wander
like beasts, while their cruel enemies exult in the miseries
they have brought upon them, and glory in doing
all the mischief they can, and spreading devastation as
wide as possible? Thus, every passion, inimical to health,
must, on both sides, be carried to its utmost height; and
if these horrid scenes overspread a great part of the earth,
for hundreds of years together, is it any wonder that
plagues should ensue? If man, forgetting the dignity of
his nature, converts the habitation assigned him by his
Maker into a kind of hell, and himself into a devil, can
we wonder that, in such circumstances, the spirit of life,
originally appointed for his use, should become to such a
being the spirit of death? Dr. Moseley seems to speak
slightly of Helmont for assigning moral causes to fever;
but if we consider the matter attentively it will certainly
be found that the moral conduct of the human race in
general has more connexion with the diseases which befal
them, than we are perhaps willing to believe.
Most authors speak of some hidden, unknown and
unsearchable power in the atmosphere as the occasion
of plagues and other epidemics; and, from what has
been already laid down, it seems by no means improbable
that this hidden power resides in the electric part of
it. But we know that electricity proceeds from the
earth, as well as from the air; so that in some countries
the evaporation of electric matter from the earth may
affect the health of the inhabitants, as well as the constitution
of the atmosphere. Hence some spots may be
naturally unhealthy, and incurably so, independent of
either the perceptible or imperceptible properties of the
air; their healthiness may occasionally increase or decrease
by means entirely beyond the reach of our investigation.
Here then our inquiries must stop. We may
indeed make a general conjecture that such differences
are produced by the action of the electric matter; but,
unless this action be pointed out, and some connexion
traced between the situation of the country and a particular
mode of action of the fluid, we may as well own
our ignorance at once.
9. From all that has been said, then, we may conclude,
that none of the obvious properties of the atmosphere,
or of any constituent part of it, or of any variation
in the proportion of its ingredients, can be accounted
the cause of epidemic diseases; that the hidden constitution
of the atmosphere may with probability be
attributed to the agency of the electric fluid, and that
by the action of this secret cause, along with the other
more obvious properties of the air, such as heat or cold,
moisture or dryness, &c. the human body may be so
predisposed to diseases, that they will readily break forth;
and that the conduct of mankind themselves may
greatly contribute to this predisposition; the question
then is, supposing every thing to be thus laid, like a
train of gun-powder, what is the spark which first sets it
on fire. Does the disease arise spontaneously in the first
person affected by it, or does it come from without?
In answer to this we must in the first place observe,
that the accounts of all plagues mentioned in profane
history trace their progress from one place to another;
whence the probability is, that at its origin the disease was
confined to a few, perhaps to a single person. In very few
cases, however, has it been possible to trace it to an individual;
and, even when this has been done, the unfortunate
individual is always said to come from some
other place. The instance quoted from Dr. Moore is
perhaps the only one upon record where the plague
arose spontaneously in any person separated from society;
and from a single instance little can be inferred.
In those terrible examples we have given of people being
burned to death without any accident from terrestrial
fuel, the agent seems almost certainly to have been
electricity. In the plague of Procopius, said not to have
been infectious, the strokes complained of by many patients
seem to indicate an action of the same fluid. The same
in the plague at London, which was infectious, and
likewise of others. But, in cases of plagues which are
not infectious, another question arises—By what means
do such diseases spread from place to place? for even
this dreadful pestilence of Procopius did not overspread
the earth at once, but is said to have begun at
Pelusium in Egypt. To this no answer can be given.
To suppose an omnipresent contagion in the atmosphere,
proceeding either from contagion or any thing else,
cannot be admitted; for upon this supposition the
whole world must have been infected at once. The
cause, whatever it was, plainly moved from one place to
another, or was successively generated in different places.
Recourse may be had to the precipitation of the contagious
matter of former plagues from the atmosphere; but
to account for this in succession will be found very difficult;
and the same difficulty will attend every other
solution which may be attempted. Mr. Gibbon indeed
censures Procopius for supposing it not to have been infectious;
and perhaps the spreading of the disease by
infection is the only way by which we can account, in
a satisfactory manner, for the way in which it diffused
itself over the world, which was, by first infecting the
maritime places, and afterwards those which were more
inland; always visiting the second year those whom it
had spared the first.
10. Lastly, to form some idea of the nature of contagion,
or infection, as it is more properly called, we must
consider, that as the ethereal fluid, acting as heat, pervades
the human body, so doth it likewise under that
particular modification which we call electricity. Some
kinds of air, indeed most of those with which we are acquainted,
seem to act by augmenting or diminishing the
latent or the sensible heat of the body. Such, when taken
in moderate quantity, may produce slight diseases, as
head-ach, &c. and, when taken very largely, may even
put an end to life at once, either by rarefaction of the
blood and rupture of the small vessels, as is the case with
fixed air, or by oppressing the lungs entirely with their
basis, which cannot be thrown out by the breath as in ordinary
respiration. Others may affect the electricity of
it, or what in this treatise has been called the vital spirit,
as well as the latent or sensible heat. The consequence
of this will be diseases of a more serious nature;
for upon this principle in all probability depend not only
the secretion and proper regulation of the nervous fluid,
but what has been called the crafts, or proper consistence
of the blood and other fluids. Hence it is possible
that such an instantaneous shock may be given to
the body, as will not only injure the organization in an
irreparable manner, but may be felt throughout the
whole body like an electric stroke, even though there be
no visible fire, or sensation of burning, as in the case of
the Italian priest and others, who perished in such a miserable
manner.
Formerly all acute diseases were supposed to depend
on morbific matter taken into the body, and absorbed
by the blood: the cure was thought to be accomplished
by the expulsion of this morbific matter from the body
by sweat, or some of the other natural evacuations.
The doctrine was attended by many difficulties, and in
many cases did not admit of a satisfactory explanation.
It was therefore laid aside, and the debility or excitement
of the nervous system arose in its place. But this
new system admitting of miasmata and contagion, it was
plain that morbific matter still kept its ground. With
a view, it would seem, to render the nervous theory more
complete, it has been found necessary to deny the doctrine
of contagion and infection entirely. This has been
done, wherever there was a possibility; but the phenomena
of the small-pox and measles, as well as those arising
from poisons, still militated strongly in favour of
morbific matter. To avoid the force of arguments
drawn from these sources, the doctrine of absorption was
denied, and contagions of all kinds were said to act immediately
upon the nervous system without affecting the
blood or other fluids. At last the matter seemed to be
decided by the experiments of the Abbe Fontana on
poisons. He found that some proved fatal by being
mixed with the blood, others by being applied to the
nerves, and others by being taken into the stomach.
Even this did not give satisfaction. It was contended
that the effects of poisonous bites were too quick to be
accounted for on the principle of absorption; that, after
the most violent symptoms had commenced, they might
be removed by cutting out the part affected; and consequently
that, instead of any absorption by the blood, we
were only to believe that the nervous system was irritated.
“Poisons, (says Dr. Girtanner) remedies, and, in general,
all surrounding bodies, acting only on the irritable
fibre, it follows that they act upon the system in
a similar manner, and that every substance capable of
producing the greatest possible effect upon the fibre,
that is to say, every substance capable of exhausting all
the irritability both of the fibre itself and of the system,
in an instant, as for instance, laurel water, or white arsenic,
is also capable of producing all the inferior degrees
of action, either by acting on a fibre less irritable,
or by acting upon the same fibre, but in a less quantity.
Laurel water, opium, white arsenic, ammoniac,
are of course both medicines and poisons capable
of healing, as well as of producing, all maladies whatsoever,
without exception.93 And this is confirmed by a
number of experiments which I have made upon different
animals. This truth seems to me of the utmost
importance; and the Abbe Fontana, who made more
than six hundred experiments to prove that ammoniac
is no remedy against the bite of a viper, would have
saved himself the trouble, had he known it. If, instead
of applying the venom of the viper to so many animals,
and afterwards applying ammoniac to the wound, he
had made a single comparative experiment, and applied
ammoniac to a wound made by a lancet that was
not poisoned, he would have found that ammoniac
itself, applied in this manner, would have produced a
disease exactly analogous to that caused by the venom
of the viper; and, consequently, so far from removing
the malady, must necessarily increase it, by exhausting
the irritability of the fibre in a much less time than
the venom of the viper by itself was capable of doing.
Mr. Fontana has made more than six thousand experiments
upon the poison of the viper; he employed
more than three thousand vipers, and caused to be bit
more than four thousand animals; and the conclusion
he drew after this truly enormous number of observations
was, that the poison of the viper kills all animals,
and produces the disease by its action on the blood.
But why did Mr. Fontana neglect to make the decisive
experiment, the experimentum crucis of Bacon?
It is well known that frogs, and many animals with
cold blood, live a long time without the heart, and
entirely deprived of blood. If therefore the poison of
the viper kills animals by its action on the blood, it
will not destroy frogs without blood. But experiment
contradicts this reasoning. The poison of the viper
will kill frogs without blood in as short a time as it
kills those animals who have not lost their blood. It
is not therefore by its action upon the blood that the
venom of the viper destroys animals; and thus does it
happen that a single experiment frequently overturns
all that six thousand other experiments have apparently
established. According to my experiments, poisons
operate upon the blood just as they do upon the muscular
fibre, by depriving it of its principle of irritability,
or of its oxygen. After having made this observation
upon the experiments of Mr. Fontana, I must do him
the justice to add, that I have found all his experiments
very accurate, and that in all those which I have
repeated, the result has been exactly conformable to
the account given by him; it is in his conclusion only
that he appears to be deceived.”
On this I must in the first place observe, that since
philosophers and truth seem to be so far distant from each
other that even six thousand experiments cannot bring
them together, it were greatly to be wished that in their
researches they would pay a little more regard to humanity.
If the Author of Nature has set man at the head
of the creation, if inferior animals must patiently resign
their lives to preserve ours, are we therefore authorised
to torment and put them to death by thousands
for every idle whim that comes into our heads? After
Spallanzani, Fontana, Girtanner and a multitude of other
learned barbarians had cut in pieces, boiled alive, poisoned
and tortured thousands of inoffensive animals, new massacres
it seems must be made, and new tortures inflicted,
because an experimentum crucis is still wanted! If
knowledge is to be obtained only by such means as
these, it certainly must be derived from a very polluted
source.
2. The experiment on which Dr. Girtanner builds
so much is far from being above suspicion. Though
we may cut the heart out of an animal, and let it bleed
as freely as possible, yet we certainly overrate our abilities
if we say that all the blood is taken out of it. The
more perfectly an animal is bled, the less irritability it
has; which gives a reasonable suspicion, that, if all the
blood could be taken away, the irritability would cease
entirely. In frogs, and all other cold blooded animals,
the blood contains fewer red globules than in such as
are warmer; the circulation is more languid than in
such as have warm blood, and, of consequence, the
blood will retain its irritability for a longer time, and it
will likewise be more difficult to deprive the body of all
its blood. In making this experiment, therefore, Dr.
Girtanner ought to have brought unexceptionable proofs
that he had deprived the frog of all the blood it contained.
But, as this was not done, we shall be ready to
suspect that some was left; in which case we should be
still as uncertain as before whether the poison acted on
the irritable fibre, or on the blood. But the decisive
experiment, or experimentum crucis, seems to have been
made by Fontana himself, by injecting a little of the
diluted poison of the ticunas into the jugular vein of a
rabbit. Here the poison was applied to the blood itself.
It could get at no other part of the fibre but the inside
of the vein, which is not accounted very irritable; and
the quantity injected was so small, that the Abbe thought
his experiment had failed; yet the animal died as if by
lightning. The moment he turned his eyes towards it,
it was absolutely dead, without discovering the least
convulsive agony, or other sign of some little life remaining,
generally observable for some time in animals killed
by the common methods. On applying the same poison
to a large nerve of another animal of the same species,
no injury followed.
3. The dispute is of no consequence, and the experiment
will prove the same thing whether we suppose the
poison to act upon the irritable fibre (the nerves and
muscles) or upon the blood. The only important point
to be ascertained is, whether there be in nature any substance
which, applied to the internal parts of the body,
or to a wound, will instantly disorder the whole in such
a manner as to bring on a violent disease which may
prove mortal in a short time. If any such there is, that
substance, whether solid or fluid, visible or invisible, may
with propriety be called contagion; and if any such proceeds
from the body of a diseased person to one in health, the
vapour so proceeding is infection. As to the mode of its
operation we are little concerned; the sudden manner
in which people are affected shows that poisons kill by
suppressing in a very short time the principle of life,
which seems to be analogous to electricity, or rather the
very same with it; neither is it more incredible that the
poison of a serpent should kill by disturbing the natural
electricity of the body, than that the stroke of a torpedo,
or electrical eel, should kill by the same means. The
only difference is, that, in the case of poisons, the pernicious
substance is introduced into the body itself; in
the torpedo, it comes with violence from without. The
former we may compare to the silent discharge of an
electrified jar by a point, the latter to its discharge with
a violent flash by a knob. But that in poisonous bites
the blood is greatly affected, and that in a very short time,
we certainly know. There are some kinds of serpents
whose bites are so suddenly fatal, that no cure can be
applied: one of these, called the small laharra, is mentioned
by Mr. Bancroft in his Natural History of Guiana.
Mr. D’Opsonville, in his Philosophic Essays, takes
notice of one in the East-Indies, which he calls the poison
serpent or serpent poison, which seems to be as bad as
the laharra mentioned by Bancroft. This too is but
small, viz. two feet long, and very slender. Its skin is
freckled with “little traits of brown, or a pale red, and
contrasted with a ground of dirty yellow: it is mostly
found in dry and rocky places, and its bite proves mortal
in less than one or two minutes. In the year 1759,
and in the province of Cadapet, I saw several instances
of it; and, among others, one very singular,
in the midst of a corps of troops, commanded
by M. de Bussy. An Indian Gentoo merchant perceived
a Mahometan soldier of his acquaintance
going to kill one of these reptiles, which he had found
sleeping under his packet. The Gentoo flew to beg
its life, protesting that it would do no hurt if it was
not first provoked; passing at the same time his hand
under its belly, to carry it out of the camp; when
suddenly it twisted round, and bit his little finger;
upon which this unfortunate martyr of a fanatic charity
gave a shriek, took a few steps, and fell down insensible.
They flew to his assistance, applied the serpent-stone,
fire, and scarifications, but they were all
ineffectual; his blood was already coagulated.94 About
an hour after I saw the body as they were going to
burn it, and I thought I perceived some indications
of a complete dissolution of the blood.”
The bite of the brulan or burning serpent, according to
the same author, is almost as terrible. “This is nearly
of the same form with the last, its skin is not quite so
deep a brown, and is speckled with dark green spots:
its poison is almost as dangerous, but it is less active,
and its effects are very different. In some persons it is
a devouring fire, which, as it circulates through the
veins, presently occasions death; the blood dissolves
into a lymphatic liquor resembling thin broth, without
apparently having passed through the intermediate
state of coagulation,95 and runs from eyes, nose and
ears, and even through the pores. In other subjects
the poison seems to have changed the very nature of
the humours in dissolving them; the skin is chapped
and becomes scaly, the hair falls off, the members are
tumefied, the patient feels all over his body the most
racking pains, then numbness, and is not long in
perishing.”
From these accounts it is plain that poisons do operate
very powerfully on the blood; and if they do so in
one case it is reasonable to think that they do so in all.
According to the degree of strength of the poison, however,
we are sure that the effects will be more or less visible
to us; but, though we should not be able to perceive
any alteration whatever in the consistence or colour
of the vital fluid, we cannot positively say that it has
not undergone any change; for the spirit which operates
in it is too subtile for our observation. In the beginning
of almost all diseases, perhaps, blood drawn from a
vein will not be perceptibly different from that of a person
in health; and Dr. Fordyce particularly takes notice
of this in fevers; but as the disease goes on, an alteration
becomes very perceptible, which gives just
ground for suspicion, that there had been some alteration
from the very first, though invisible to us.
After all our disputes, however, we shall find that the
controversy, though ultimately important, begins more
about words and trifles than any thing else. Dr. Brown
used the word excitability, Dr. Girtanner uses irritability,
and the author of this treatise, the words vital spirit and
electricity, to express something equally unknown to them
all. The only difference is, that Drs. Brown and Girtanner
speak of their excitability and irritability as a
kind of power essentially inherent in living bodies, acted
upon indeed by certain substances, but incapable of deriving
any supply from without; the author of this treatise
considers it only as a modification in the human body,
or an organization, if we please to call it so, of that fluid
which he believes to be universally diffused, under the
names of heat, light and electricity. Hence that portion
modified or organized in the human body must be
under an entire and absolute dependence upon the immense
mass of surrounding fluid, and, by any alteration
in the motions of it, must be often very perceptibly affected;
nevertheless as this fluid was originally created
to preserve and not to destroy human life, there is much
less danger from a natural than from an artificial commotion
in it. In some visible bodies, such as poisons,
the fluid acts in such a manner as to counteract the operation
of that part which is organized in the blood or
nerves, or both. Hence on the introduction of such
into the body the disorder flies like lightning through all
parts of it, and in a very short time brings on death.
In those vapours properly called contagions, the opposite
action is less violent, and therefore the disorders they produce
are in proportion. Hence such diseases may either
be promoted or retarded by the perceptible properties of
the atmosphere, which in poisons have little or no effect.
There is indeed a remarkable difference in the strength
of the poison secreted in the bodies of serpents at certain
seasons of the year, or according to their food. M.
D’Opsonville observes that the poison of serpents is in
general more powerful, the more they live in hot and
dry places, where they feed upon insects that are full of
saline, volatile and acrimonious particles. But, notwithstanding
this difference in the strength of poisons according
to the circumstances of time and place, there is not
the least reason to suppose that poison of a given strength
would not produce the very same effects, let the state of
the atmosphere be what it would.
If therefore we certainly know that there are some
kinds of aerial vapours which when applied to the human
body do exert a power directly opposite to the vital
principle, there is no reason to doubt that such vapours
may be confined among certain soft substances, such as
cotton, wool, &c. and remain there for an unknown
length of time, again exerting their malignant powers,
when a fresh object comes in their way. Besides, as all
kinds of air with which we are acquainted consist of a
basis united with the ethereal fluid and volatilised by it,
there is reason to suppose that contagions themselves are
formed in the same manner. Some kinds of air also are
very easily decomposed, in which case the basis attaches
itself to some terrestrial substance, the ethereal fluid
which volatilised it diffusing itself around in an invisible
manner, but generally with a perceptible heat. Fixed
air affords a notable example of this; for, by exposing it to
lime-water, or even dry lime, alkaline salt, volatile alkali,
or common water, a decomposition of the air very
readily takes place, and its basis is found to be attached
to those substances. What happens to fixed air may
also happen to contagion. The basis of it may have a
tendency to unite itself to cotton, or such like substances,
and thus may not only infect them, but concentrate
itself to such a degree as to produce a disease much more
violent than that of the person who gave the infection;
and something of this kind has even been observed with
regard to infected cotton. But now another question
occurs: As fixed air, by being attached to terrestrial
substances, loses its aerial property, why should the basis
of contagious effluvia still retain its malignant quality
though in a state of decomposition? Here we are again
helped out by analogy. Fixed air is known to be capable
of resuming its aerial properties occasionally, from
causes unknown to us, though we cannot suppose them
to be any thing else than the invisible action of the
ethereal fluid so often mentioned; which, being guided
by laws unknown to us, we cannot possibly comprehend.
The fact, however, is certain, that the basis of fixed air
does very often quit the substances to which it is attached,
and assume an aerial state in great quantity, and
with very mischievous effects. Thus the old lavas of
volcanoes, if chemically tried will be found at all times
to contain great quantities of the basis of fixed air, but it
is only at some times that the mofetes which are supposed
to be the air itself, break forth.96 In like manner the
strata under ground always contain great quantities of the
aerial basis, but the damps in mines, which are certainly
known to consist mostly of fixed air, do not always appear;
neither do they gradually accumulate, but come
suddenly, spreading unexpected destruction among those
who unfortunately come in their way. The same may
take place with contagion. After remaining some time
in a state of decomposition it may have a tendency to
become volatile again, or it may lie dormant entirely;
and this last will explain what is quoted from Dr. Russel,
p. 178, that sometimes commerce may be carried on
with infected places without danger.
Thus we see that the dispute, originally begun about
a word, involves at last a matter of the utmost importance;
for, if it be found unreasonable to believe that
any such thing as contagion exists or can exist, it follows
of course that it is also unreasonable to take any precautions
against it. Mr. McLean even goes a step beyond
those who deny the existence of contagion; for we find
him also denying that putrid effluvia can produce epidemics;
according to which doctrine, it seems, we may
not only safely visit places accounted the most dangerous
on account of infection, but live in all manner of filth
and nastiness with impunity. It is plain that no person
can ever prove that it is impossible for contagion or any
thing else to have an existence. Indeed if nothing had
ever induced people to believe that it did exist, it would
have been superfluous to say any thing about it. But
when we have innumerable testimonies to the contrary;
when the opinions of the greatest physicians, as Dr. Lind,
Dr. Clarke, Dr. Mead, Dr. Sydenham, Dr. Fordyce,
Dr. Russel, &c. agree that not only the plague, but
every kind of fever, is infectious; when we know from
the analogy of nature that contagion may exist; when
we know that there certainly are powers in nature able to
produce it; is all this to be thrown aside merely on the
strength of a theory, and a theory too which can never be
proved? for it is impossible to prove the non-existence of
any thing, much less the impossibility of its existence.
The lives of mankind are too precious to be sported
with on philosophical theories; and prudence will always
suggest, that wherever danger may at any time arise,
there it is proper to be on our guard.
Dismissing at length the subject of contagion in general,
we now enter upon the question, Whether doth it
appear from fair investigation of testimony, that the
plague has, at any time, been communicated by contagion
or not? And here I shall confine myself to what
has been adduced by Dr. P. Russel on the subject; for,
if we find that the disease has only once been introduced
by contagion, it signifies nothing though we were able
to prove, which we never can do, that it had been an
hundred times bred in some other way. The matter is
of too great importance to allow even a chance of its importation
by the neglect of the precautions necessary to
prevent it.
Our author begins with observing, that though the infectious
nature of the plague had been a question much
agitated in the schools, “it was less to be expected that
physicians who had been engaged in practice among
the infected should have persisted in the opinion that
the disease was never communicated by contagion.”
Such, however, has been the case. In 1720 some French
physicians laboured exceedingly to prove that the plague
which then raged at Marseilles and throughout Provence
arose from corrupt humours bred in the body in
consequence of irregularity in the seasons, and bad aliment;
that it was spread by the same means, in concurrence
with terror, grief, despondence, or other debilitating
affections of the mind; but was neither bred nor
disseminated contagion. Dr. Russel mentions in a note,
seemingly with surprise, that “so late as the year 1778,
Dr. Stoll of Vienna should have written expressly
against the doctrine of pestilential contagion.” To
this professor he thinks it a sufficient answer to quote
the following passage from Mr. Howard on Lazarettos,
“It must appear very strange, that he should go back to
Livy’s Roman History for proofs to establish his point,
totally neglecting all the facts concerning the numerous
visitations of the plague recorded in modern medical
books, or which had happened during his own
time. I suppose professional men will lay very little
stress upon all that can be said on pestilential diseases,
in general, which happened in wars and sieges two
thousand years ago, as applied to the plague properly
so called, a disease then confounded with various
others from which the accuracy of latter observations
have sufficiently distinguished it.”
Dr. Russel complains of the French physicians at
Marseilles having made unfair representations; particularly
that while they produce as irrefragable arguments
against contagion their own escape unhurt, amid circumstances
of supposed danger, they pass slightly over, or
omit all mention of numbers of the medical assistants
whom they saw perish in the exercise of their profession.
M. Dedier, however, who at first opposed the doctrine
of infection, at last renounced his opinions so far as to
allow that the disease might be communicated to dogs
by injecting pestiferous bile into their veins; and he
likewise admitted that it might be communicated from
one human creature to another, by drawing in for a considerable
time the breath of a diseased person, putting on
his shirt, lying in the same bed-clothes, and touching
the wounded parts of one’s own body with hands embrued
with the sweat or blood of one infected. He affirms,
however, that the atmosphere of a person in the plague
is no more to be dreaded than that of a venereal patient;
and that the touching or dressing of buboes or
carbuncles is not attended with any danger. He restricts
the infectious quality of the humours to the bile;
but the inoculation of a person by the matter of a pestilential
ulcer97 undoubtedly decides this point against
him.
On the subject of contagion Dr. Russel observes, that
the vague manner in which the word has been used has
given rise to much confusion. Some, taking advantage
of the inaccurate mode of expression on this subject used
by Dr. Mead, attacked him with sophistical nonsense.
The following may serve as a specimen, from a pamphlet
entitled “Distinct Notions of the Plague, &c. by
the Explainer.” This explainer observes, that, according
to Dr. Mead, “air and his other causes propagate and
spread contagion, not the plague; and therefore either
contagion and the plague are the same, or else the
plague is not considered; if the first, then his causes
propagate the plague; and the plague accompanies
the plague; an excellent defence! But, if the plague
is out of the play, then contagion accompanies nothing.”—From
writers like this we certainly can expect
nothing.
The opinion of Dr. Cullen concerning contagion has
been already noticed, p. 179; but though he supposes
it to be a matter floating in the atmosphere, he observes
that contagions are never “found to act but when they
are near to the sources from whence they arise; that
is, either near to the bodies of men, from which they
immediately issue, or near to some substances which,
as having been near to the bodies of men, are embued
with their effluvia, and in which substances these
effluvia are sometimes retained in an active state for a
very long time. The substances thus embued with
an active matter may be called fomites; and it appears
to me probable, that contagions as they arise from fomites,
are more powerful than as they arise immediately
from the human body.” This opinion concerning
the great power of contagion imbibed by certain
substances is conformable to what was above laid down
by reasoning a priori on the nature of contagion.98 It
is doubted by Dr. Russel, but Dr. Lind adopts it, and
Van Swieten gives his opinion to the same purpose.
“I am convinced, that the body of the diseased, kept
exactly neat and clean, is not so liable to impress the
taint, as his late wearing apparel, dirty linen, and uncleanliness
of any sort about him long retained in that
impure state. I say, these last contain a more concentrated
and contagious poison than the newly emitted
effluvia or excretions of the sick.”
With regard to the original cause, our author observes,
“that the plague is bred or produced originally from
vitiated human effluvia, is a matter which has by no
means been established on proper authority.” Setting
aside therefore inquiries of this kind, he thinks it sufficient
to inquire whether the infection be not communicated
from a sick to a sound person by immediate contact;
whether it be not also communicated at some distance
through the medium of the air; and whether substances
of various kinds do not imbibe the infectious effluvia,
and retain them for a considerable time. So far
as these points admit of proof from the experience of
times past, the question concerning pestilential contagion
will admit of a solution, independent of all theoretic reasoning
whatever.
2. On the subject of contagion people have been
embarrassed by confounding the true plague with other
malignant diseases. This has been done, not only by
the ancients, but by some moderns; and our author
quotes Dr. Pye, saying “that any epidemic sickness,
which rages with more than ordinary violence, and
which occasions extraordinary mortality amongst
mankind, may be, and is, properly termed a pestilence,
or the plague.” By not attending to the proper
distinctions, in these cases, circumstances belonging
to what are commonly termed malignant or pestilential
fevers will often come to be very improperly applied to
the true plague.
3. “It may be remarked, that those who contend
in favour of contagion, from zeal for accumulating
proofs, have collected a number of facts from historical
records of very unequal authority, and often with little
critical skill in discrimination. Of this error their
antagonists availing themselves, have selected from the
mass the instances most liable to doubt or objection,
and have endeavoured, by their manner of arranging
them, to place the whole in a ridiculous light; while
more important instances are either evasively past
over, misstated in the representation, or invalidated by
general declamation on the little credit due to historians
in matters of physic, or the prejudices prevalent
in ancient times of ignorance, and on contradictions
to be found in the arguments of those who support
the system of contagion.”
To this the Doctor adds the great quantity of hypothetical
reasoning which has been introduced into the
controversy, and above all the unfair dealing of the
parties in carrying on the dispute, which has reduced
the matter from “a calm inquiry in pursuit of truth,
to a wrangling contest for victory.” Lastly he insists,
that, had it not been for the misrepresentations and
sinister dealings of those who have written against contagion,
“the question seems to have been properly resolved
in the affirmative;” and he complains greatly of
the conduct of the Montpelier physicians in this respect,
insomuch that “their misstating of circumstances, and
the partiality so evidently discoverable in their narrative
of cases, will serve more effectually to remove
doubts on the subject, than any arguments that could
be used against their hypothesis.”
On the subject of contagion our author observes,
that some difficulties still remain; but these, though
proper subjects of future inquiry, “do not appear to be
of force sufficient to invalidate facts already established.
It is well known, that the same person who has been
inoculated two or three times for the small-pox without
effect, even in an epidemic season, has afterwards
received the infection upon repeating the operation
at a distance of time when the disease was hardly sporadic.
The cause of this remains unknown; but ignorance
of it was never produced as an argument
against the reality of variolous contagion. . . . If,
of one hundred persons exposed to the infection of
the plague by a near aproach to the sick, ninety
should fall sick, shall human inability to assign satisfactory
reasons for the escape of the other ten be converted
into a positive proof against the disease having
been caught by contagion? If persons retired from all
commerce with the infected and their attendants,
breathing the same air with the rest of the inhabitants,
and nourished by the same aliment, remain untouched
during the ravage of the plague, as long as they
continue secluded, but, upon unguarded communication,
are taken ill like others; can any rational doubt
be entertained about the cause of their former security?
Or if through stealth, or neglect of requisite
precautions, substances tainted by the sick should be
conveyed into these secluded retreats, and persons
living temperately as before, ignorant of what had
happened, and consequently in the midst of imaginary
security, happen to be seized with the distemper; can
it with any show of reason be ascribed, not to contagion,
but to terror, or to colluvies in the stomach and
bowels, produced by intemperance and bad aliment?
The instances here alluded to are not the creation of
fancy, but strictly consonant to repeated experience in
Turky; to say nothing at present of what has been observed
at Marseilles and in various cities in Europe.”
“But a greater difficulty than that of all persons not
being equally susceptible of the infection arises from
the cessation of the plague, at a period when the supposed
contagious effluvia, preserved in apparel, furniture,
and other fomites, at the end of a pestilential
season, must be allowed to exist, not only in a much
greater quantity than can be supposed to be at once
accidentally imported by commerce, but in a state
also of universal dispersion over the city: the fact,
however unaccountable, is unquestionably certain;
the distemper seems to be extinguished by some cause
or causes equally unknown as those which concurred to
render it more or less epidemical in its advance and at
its height. In Europe something may be ascribed to
the means employed for the cleansing of houses and
goods supposed liable to retain the latent seeds of infection;
but, at Aleppo, where the distemper is left to
take its natural course, and few or no means of purification
are employed, it pursues nearly the same progress
in different years: it declines and revives in certain
seasons, and, at length, without the intervention
of human aid, ceases entirely.”
On this we shall remark in general, that the failure of
contagion in some cases to produce the usual effects may
proceed from some constitution of the body, disposing it
not to allow the cause to produce its usual effects at one
time, though at another, the constitution may be so far
changed as very readily to admit it. This opinion has
been very generally received among medical people, who
have, to this singularity of constitution given the name
of idiosyncrasy. It is, however laughed at by Mr. McLean.
“As the fact (says he) cannot be denied, that a great
majority have escaped after contact with persons ill of
diseases supposed to be contagious, attempts may perhaps
be made to account for it by supposing a certain
peculiarity of constitution, which exempts from, or
disposes to, disease. Is it the many who escape that
have this happy peculiarity of constitution; or the few
who are seized that are so unfortunate as to possesses it?
The former are evidently too numerous to admit such
an hypothesis. The property must therefore, I conclude,
be given to the latter. But a child here and
there is exempted from small-pox, although exposed
to its contagion. In order to preserve a consistency,
this fact must be accounted for by the same or another
peculiarity of constitution. Peculiarities of constitution,
then, exempt from contagion in one case, and
dispose to it in another; and thus a term, which in
reality means nothing, may be made to account for
any thing. For my own part I confess my inability to
comprehend any other peculiarities of constitution, or
idiosyncrasies of habit, than what are constituted by the
different degrees of health and disease; the different
states of the excitability.”
In the same manner that Mr. McLean argues with
regard to disease, let us argue concerning bodily strength.
Some men are able to lift a weight of 6 or 700 pounds,
but a great majority cannot lift above 300. Whence
proceeds the difference? Is it the few who lift the great
weight that by nature have more strength, or is it the
many who can lift only the smaller that by nature have
less? This is precisely his argument, and there needs no
other refutation than stating it in this manner. What
he calls the states of excitability are as much idiosyncrasies
at the time as any thing else. Mr. McLean will not
deny that a person debilitated by certain causes is more
liable to be seized with typhus fever than one who is not.
What does this proceed from, but that the body of the
one is prepared for the disease, is constitutionally disposed
to receive it, or has an idiosyncrasy of habit disposing to
it, which the other has not? It is true, that unless we
point out the circumstances which constitute this idiosyncracy
we do nothing; but Mr. McLean’s scheme, of
resolving every thing into excitability, would forever prevent
us from doing so. This is the great deficiency of
the Brunonian system altogether; for, by attending
only to the animal life of the body, he seems to have
absolutely forgot that we had any thing in common with
vegetables. The bones, for instance, or indeed any part
of the body, cannot be formed by the power which governs
it after it was formed. The growth of the human
body is as strict vegetation as that of a tree; and therefore
we find that after the excitability is entirely gone,
after death has taken place for a considerable time, the
body still retains its form, and would do so forever, did
not other powers interfere with it. Human life therefore
is a compound of the vegetable and animal life, the former
being the basis of the latter; and it is the vegetable
life which is much more commonly the subject of disease
than the animal life. In vegetables we observe an idiosyncracy
of habit, as well as among animals. Some, even
of the same species, are much more vigorous than others,
and, among some, diseases are much more common than
others. In like manner among the human race some
are strong, others weak; in some the blood is much more
confident, and coagulates on exposure to the air much
more firmly than in others. Excitability, or excitement,
is common to all, and the degrees of it (though enumerated
by Yates and McLean in a kind of thermometrical
scale) must be merely imaginary, because excitability is
not the object of our senses. The obvious properties of
the body itself, independent of any excitement whatever,
are principally to be considered in medicine. These
constitute the peculiar constitution, or the idiosyncracy of
habit, belonging to each individual. Yet, in defiance
of every confederation of these obvious properties, which
all have access to observe, the new system leads us only
to consider an invisible and unknown being called excitability.
Hence diseases peculiar to certain constitutions
more than others are said to be occasioned only by certain
degrees of excitability common to all, or perhaps to
consist in these very degrees themselves. Thus a peculiar
mode of practice has been introduced, in which almost
the whole materia medica is rejected. We have
already quoted Dr. Girtanner, saying that all diseases
whatever may be cured, as well as produced, by only four
articles; but in the following quotation he goes still farther.
“The art of pharmacy and the science of prescription
will become useless; a phial of alcohol or
laudanum will supply the place of that enormous
quantity of drugs which crowd the shops of apothecaries.
The trade of the druggist——but hold; if I
continue this prophetic language, I shall only expose
myself to ridicule,” &c. Reveries of this kind certainly
deserve the most severe reproof. People may no
doubt amuse themselves with theories as well as any thing
else, while these theories continue inoffensive; but when
the belief of them leads to a rejection of what has been
established by the experience of many ages, they begin to
assume a consequence which they originally had not.
We have already seen that a disbelief of the doctrine of
contagion leads people into a practice accounted dangerous
by many, and which cannot be proved to be safe.
A total rejection of medicines, the efficacy of which
have been attested by thousands, and which never can
be proved to have no efficacy, must be attended with still
worse consequences, as thus we should be deprived of
the means of curing those diseases which our imprudence
in rejecting the former doctrine might have brought on.
But, to return to the subject of the plague.
The disappearance of the disease, while all the causes
that we suppose capable of producing it remain in full
force, is a demonstration that it depends on something
entirely distinct from the human body, and from all
those powers which perceptibly act upon it. It proves
that this unknown power has only a temporary existence,
coming to perfection at one season, and dying away in
another; sometimes capable of being revived, and sometimes
not. This corresponds entirely with what has
been laid down concerning contagion itself, viz. that
like other aerial vapours it is capable of decomposition,
and remaining for an uncertain length of time in a dormant
state; but that occasionally it may revive, and appear
unexpectedly, as mofetes arise from lavas, or damps
in mines. After a city has been thoroughly infected
with a pestilential disorder, therefore, there can be no security
against its re-appearance; it being impossible to
know whether the contagion may not be still existing
and capable of being revived by some unknown cause,
though it has been dormant ever so long. In such cases
it may with propriety be said to have arisen spontaneously,
though, had it not been there at a former period, there
could be no reason to think that it would have appeared
at that time.
Dr. Russel next takes into consideration the plague at
Marseilles in 1720, of which he says the accounts “are
more full, and circumstances better authenticated,
than most of the accounts of anterior plagues to be met
with in books.” From the opposition to the doctrine
of contagion at the time, he also supposes that the facts
relative to its introduction would be severely scrutinized,
and falsehoods detected: “but (says he) if, instead of
such detection, the most material have been passed
over in silence, and little more than hypothetical reasoning
opposed to others, the main facts may be considered
as established, if possible, more firmly than
they were before.” These facts are stated as follows:
“1. That the plague did not exist in France before the
25th of May, 1720. 2. That it was imported in
goods from the Levant, by a ship which left the coast
of Syria the beginning of February, and arrived at
Marseilles the 25th of May. Two days after her arrival
one of the sailors died; an officer of quarantine
who had been put on board died on the 12th of June,
and a cabin boy on the 23d. Some porters employed
in opening the merchandise at the lazaretto also died
about this time. Three others were taken ill in the beginning
of July, with buboes in the groin and axilla.
This alarmed the surgeon of the lazaretto; a consultation
was held with two other surgeons on the 28th;
the disease was unanimously declared to be the plague,
and the three patients died next day: the surgeon of
the lazaretto, with part of his family, and the priest
who attended the sick, were also taken ill and died.”
From the lazaretto the disease made its way into the
city, and began to appear about the 20th of June. By
what means it was introduced is not directly said; but
it seems to have been by smuggling infected goods. In
the beginning of July it began to spread; but a kind of
pause having taken place between the 12th and 23d,
the physicians were reproached with having mistaken the
distemper. During this supposed interval, however,
it was discovered on the 18th of July that the disease
had spread in a certain part of the city. A surgeon,
employed to examine into the matter, declared the distemper
to be the worm-fever; and about the 23d the
council of health were informed of the death of fourteen
persons in that quarter, and of several others falling sick.
The surgeon still adhered to his opinion, but a physician
declared it to be the true plague. About the end of
the month it had got into the suburbs; four physicians
declared it to be the true plague, but their report was
not believed; they were insulted in the streets, and it
was not until some of the inhabitants of better rank
were taken ill, that the true state of the matter gained
credit.
“Such (says Dr. Russel) was the rise of the plague
at first, and its progress afterwards in the months of
June and July; whence it appears, that persons on
board the suspected ship, those employed in airing the
goods, a surgeon and a priest, who attended the sick,
were among the first infected; that the passengers
from the several ships, all of which ships, the first
excepted, brought foul patents, were, together with
their baggage, admitted into the city, after preforming
a quarentine of little more than eighteen days; that
the distemper from the 20th of June till towards the
end of July advanced very slowly, and sometimes seemed
to pause; that it attacked chiefly the poorer sort of
people, and was found in distinct quarters of the city;
and lastly, that, during the first forty days, few or none of
the infected recovered; a circumstance entirely consonant
to what was observed in the beginning of the
plague at Aleppo.”
Three other facts are mentioned by our author, viz.
that the disease was evidently communicated by infection;
that those who were careful to seclude themselves
from all communication with the sick and with infected
goods, were not infected; and lastly, that the
disease, which began to rage violently in August, continued
to do so through that and the following month,
but declined fast in the months of October and November,
and seemed to cease in the middle of winter. Some
accidents happened in 1721, between the months of
February and July, which gave occasional alarm; but
the distemper did not spread, and ceased entirely after
the summer solstice of that year.
To all this, however, objections have been made.
1. That the irregular seasons of the former year, a bad
crop, and unwholesome aliment, had produced a malignant
epidemic, all which, joined to the popular dread of
contagion, were sufficient to produce the plague without
any imported infection. To this Dr. Russel replies,
that these positions, assumed as facts, had no existence;
for which he refers to the publications of the times.
2. It was objected that there were instances of the plague
in Marseilles before the 25th of May. These instances
are only five in number, produced by M. Deidier, “who
saw not the cases himself, yet (says Dr. Russel) from
the very imperfect accounts he had been able to glean,
he thought himself justified in declaring they bore all
the marks of the true plague. Nothing (adds the
Doctor) but extreme partiality to an hypothesis could
have led any one practised in the plague, into such a
declaration; the cases bearing every internal mark of
belonging to a different class from the plague. I shall
endeavour to show this in a few words.
“Of the five supposed infected patients, three recovered,
two died, and all had eruptions. One who
died had a parotis (the most ambiguous of all pestilential
tumours) without any concurrence, so far as
appears, of pestilential symptoms. The tumour had
appeared six days before the woman’s death, but how
long she had been sick remains unknown. The other
died the 16th or 17th day, a very unusual period in
the plague. She also had a parotis, which did not
make its appearance till the 10th or 11th day of the
disease. No pestilential symptoms whatever are mentioned.
Of the three who recovered, one was very ill
with a fever and carbuncle; but neither the invasion
nor the duration of the disease are mentioned. Another
had a carbuncle and a small tumour on the
thigh; and the third (which bears the nearest resemblance
to a very slight infection) had also a bubo in
the thigh; but the tumours in neither of these patients
are described in such a manner as distinguishes
them from ordinary tumours; and the apothecary,
who gives the account from memory, had in all likelihood
never seen a pestilential bubo before.”
“Of the persons infected for some time after the arrival
of the ships from the Levant, none had eruptions,
and all perished after a few days illness; which
agrees entirely with what was observed at Aleppo in
the beginning of the plague: hardly any of the sick
recovered, and the major part died in three or four
days, without any appearance of buboes. Upon the
whole, therefore, I think it very clearly established,
that the plague did not exist in France before the
month of May, 1720. Prior to M. Deidier, however,
I find a M. Pons had endeavoured to prove
that the plague was in Marseilles, not only before the
month of May 1720, but even in the preceding year.
I have not had an opportunity of examining that gentleman’s
book.”
3. It is objected that the disease was not brought
from the Levant by infected goods. “Captain Chataud’s
vessel, supposed to have brought the infected
goods, arrived with a clean patent, or bill of health,
having left the coast of Syria before the plague broke
out there; she consequently cannot reasonably be
thought to have transported the plague, which was
not in the ports from whence she came.”
To this Dr. Russel answers, that on commercial accounts
the Turks carefully conceal the appearance of
the plague from the Europeans. Should reports of
accidents get abroad, they are variously and contradictorily
represented, and pestilential marks and tumours
fraudulently concealed. Though Chataud obtained a
clean patent, the plague broke out soon after his departure,
and three vessels with foul patents arrived at
Marseilles a few days after Chataud. “To this (says
Dr. Russel) it may be further added, that, notwithstanding
his clean patent, persons acquainted with the
Levant will think it far from improbable, that the
plague might actually have been in Sidon when he
sailed, though unknown to the magistrate, by whom
the patents are granted. . . . A clean bill of health
imports that the place has been free from plague, and
all suspicion of plague, for a certain space of time; but
the clean patents of the two first arriving from the
Levant, after the cessation of the plague, are, according
to Mr. Howard, deemed foul at Marseilles, and the
passengers are obliged to perform a quarantine of thirty-one
days. The French consuls lying under an obligation
to insert in their patents a detail of circumstances,
it must appear strange, when the condition of
Syria at that time is considered, how Captain Chataud
should have obtained a clean patent.”
Though this must certainly be deemed a sufficient
answer to the objection, Dr. Russel goes on to give an
account of what had happened the preceding year, when
the plague had raged violently at Aleppo; and shows
that, from the condition of the whole coast of Syria, a
return of the plague was certainly to be expected; that
the French consuls could not be ignorant of this, neither
could the council of health at Marseilles be unacquainted
with what had happened at Aleppo the preceding
year. “The facility with which the patents
seem to have been issued in Turky, and the partial
indulgence of the council to Chataud’s ship, notwithstanding
the very extraordinary mortality which had
avowedly happened on the voyage, together with their
easy confidence afterwards in the reports of the surgeon
of the lazaretto, can only be accounted for from the
prevailing influence of private commercial interest over
a sense of official duty.”
Our author next proceeds to take notice of what
happened during this ship’s voyage to Marseilles. On
the 31st of January he left the coast of Syria with a
clean patent, before the plague broke out. On the 25th
of May he arrived at Marseilles, from Sidon, Tripoli and
Cyprus. On the voyage, or at Leghorn, he lost six of
the crew; but, by the certificates of the physicians of
health at Leghorn, these died only of malignant fevers
caused by unwholesome provisions. These last words in the
Traite de la Peste are said to have been interpolated at
Marseilles. At any rate, as Dr. Russel observes, they
could relate only to those who died at Leghorn, not to
the others, whom the physicians had not seen.
The other account is much less favourable. According
to it, Chataud “left Sidon the 31st of January with
a clean patent. The plague discovered itself there
a few days after his departure. Having sustained some
damage by bad weather, he put into Tripoli, where he
embarked some merchandise; he took in also some
Turks, passengers for Cyprus, together with their luggage.
Soon after the ship had left Tripoli, one of
these passengers fell sick and died. Two of the sailors
employed to throw the corpse overboard desisted at the
desire of the pilot, and the rest of the ceremony was
performed by the other Mahommedan passengers;
the ropes with which the body was lowered down, being
by way of precaution thrown into the sea. Within
a few days the two sailors who had handled the
corpse were taken sick and died. At Cyprus the ship
put her remaining passengers on shore, and made a
very short stay. Soon after her departure from that
island, a third sailor and the surgeon died of an illness
of a few days duration. The captain, justly alarmed
by these accidents, ordered the bedding and other
things used by the deceased to be thrown into the
sea; and kept himself carefully separate from the
crew during the remainder of his voyage. Some time
after this three more sailors fell sick, and, there being
no surgeon on board, the vessel put into Leghorn,
where the three sick men died, and the physician and
surgeon of the lazaretto declared the disease to be a
malignant pestilential fever.”
Our author considers the above account as a full
proof of the plague being imported by Chataud’s vessel:
he declines entering into the question about the
possibility of importing contagion in merchandise. How
this might take place has already been explained; and
the present instance of its having been imported is as
clearly proved as can be expected. A collateral proof,
with regard to the contagion of the small-pox, we have
from Dr. Huxham. A beggar, ill of that disease, approached
a certain town in England, but was not suffered
to enter, for fear of infection. The beggar died, and
the infected clothes were burnt at some distance from
the town; but the smoke being blown upon it by the
wind, the small-pox in a short time made its appearance,
beginning in that part upon which the smoke was blown.
This clearly proves that one species of contagion may adhere
to clothes, and is a very strong presumption that
any other may do the same. It also shows that contagion,
when once produced, is by no means easily destroyed;
and consequently that all kinds of purification, even
when used with the utmost care and diligence, are scarce
sufficient to ensure safety.
It would now be superfluous to enter farther into the
subject of the plague being communicated by infected
goods, did not our author quote a work of Dr. Pye of
London, in which the latter from the very Journal (which
has been used as containing arguments in favour of contagion)
makes inferences directly opposite. “The facts
related in this journal (says Dr. Pye) seemed to me
to make so clearly against the modern doctrine of contagion,
that if this writer had not mentioned them as
undeniable instances in his favour, I should not have
thought there had been any persons here in England so
dull of understanding, or so much blinded with prejudice,
as to stand in need of having these facts put
into a more obvious light: but, having this occasion,
I shall consider them more largely than otherwise I
would have done, and show that the porters, who died
in the lazaretto at Marseilles, received no hurt or
infection from the goods.
“To leave no room for objection, I shall take notice,
that a guard of quarantine died on board Chataud’s
ship the 12th of June; but, as this officer was no
ways concerned either in unloading or opening the
goods, he could receive no hurt from them; and besides,
this must have been fourteen or fifteen days after
the goods had been carried out of the ship into
the lazaretto. Further, six of their men are said to
die at Leghorn; but the town of Leghorn was not infected
from thence, which would have been more
likely if there had been any infection in the case, than
that Marseilles should be afterwards infected.
“If any infection or infectious aura can be supposed
to be packed up, and brought in goods, such infection
or infectious aura must necessarily issue forth from
them in greatest abundance, and with the greatest
force, at the first opening or unpacking of them; and,
as it must continue to fly off every moment, and be
thereby continually diminishing, it is likewise certain,
that in a very few days the goods must be in a
great measure, if not entirely, cleared of it. Wherefore,
if the porters could have been infected from the
goods at all, it must have been at the first opening of
them: but, even according to this journal, the porters
that first fell sick were not taken ill before the 23d of
June, whereas Chataud’s ship arrived the 25th of May
preceding; so that the goods of that ship, in purifying
which the porter first mentioned was employed, had
been airing and purifying for twenty-six or twenty-eight
days before this accident happened; and it cannot
be conceived that after so long a time they should
not have been entirely purged of all infection or infectious
aura, if any could have been brought with them.
Or if it can be supposed, which I think impossible, that
any part might still be left, it must withal be supposed
so much less than at first, as not to be capable of doing,
those porters especially, the least hurt: to suppose
otherwise would be to argue that the same man who
some days before had received and borne a very great
quantity and force without any injury, could then be
killed by a quantity and force infinitely less.
According to the report of merchants, Frenchmen
are not subject to the plague in Turky; and it cannot
be conceived that so small a quantity of infectious air
as can be packed up and brought in a bale of goods,
should destroy them in France, or in an air and climate
distant and different; when the whole atmosphere
of the same infectious air is found not to injure
them in very infected places, and wherein it is allowed
to be bred and generated.”
Thus far Dr Pye.—Let us now hear Dr. Russel in
answer.
“The death of the quarantine officer was mentioned
in order to leave no room for objection; but still it
may be objected that he has omitted the death of
the sailor on the 27th of May, and asserted, in contradiction
to the journal, that the former six sailors
died at Leghorn. That Leghorn was more likely to
be infected than Marseilles, is a strange notion. The
ship had landed no goods there, nor had any intercourse
with the shore; for the physician who visits
the sick on board, remains at a distance from the ship,
in a boat, and the dead bodies are sunk in the sea.
As to the circumstance of the goods of Chataud’s vessel
being all in the lazaretto before the 12th of June,
it is a supposition to be attributed to Dr. Pye’s unacquaintance
with matters of that kind; for it is impossible
a ship which arrived the 25th of May should
discharge the whole of her cargo in two or three days.
The dispatch would have been miraculous, considering
the ship lay near two leagues from the lazaretto,
and was unloaded, and the boats navigated, by her
own crew. It did not occur to Dr. Pye, that some
time, previous to the vessels beginning to unload, is
taken up in examination and other forms at Pomegue,
and the council of health. The loss of six men on the
voyage was an extraordinary circumstance, that required
deliberation; and it appears that on the 29th,
after the death of the sailor on board Chataud’s vessel,
the council determined the quarantine of his
cargo to be forty days, commencing from the landing
of the last bale; which was double the time usually
allowed for a ship with a clean patent. It is very
probable, therefore, that the ship did not begin to
unload till after the 29th of May, and possibly had
not finished when the quarantine officer died, the 12th
of June, who must have been taken ill two or three
days before.
“In regard to the time requisite for the complete
evaporation of the infectious aura, in what proportionate
gradation its activity is impaired by ventilation,
and the specific quantity required to produce
effect on the human body, they are matters which I
apprehend will not readily be admitted to be clearly
and certainly known. That the first porters were
not taken ill before the 23d of June, is very true;
but that the goods had been airing and purifying for
twenty-six or twenty-eight days, has been shown above
to be an error. The Doctor also makes two other
suppositions equally erroneous. The first, that the
whole of the cotton contained in a number of bales
is equally imbued with infectious aura; the second,
that all the bales of a ship’s cargo are opened nearly
about the same time. But, as the cotton contained
in these bales may not only have been collected from
different villages at different times, but packed up
under various circumstances relative to the materials
used for embalage, and the persons employed in embaling
or steeving them; it may easily be conceived
how the cargo of a ship, coming even from a place
where the plague actually rages, may be only partially
infected, or not infected at all. The warmest
advocate for contagion never contended for every
bale of a ship’s cargo being equally infectious. As
to the airing of the bales, it is a laborious and a
tedious process. Where there is a considerable
number, it takes up several days to open and arrange
them, goods of different kinds must be disposed separately,
accounts taken, and the cordage, &c. laid up
with care where it may be found again. The laborious
part of these operations is performed by the porters,
who also transport the goods from the water side to the
enclosure where they are to be aired: and, as the days
of quarantine do not begin to be reckoned till all the
goods are landed, the porters for some days at the beginning
are sufficiently employed in receiving and arranging
the cargo, that being the business requiring the
first dispatch. When these circumstances are considered,
it will appear no extravagant supposition, that
some of the last opened bales of Chataud’s cargo might
still retain enough of infectious aura to infect the porter
on the 23d of June. To set this retardment, almost
unavoidable in the opening of bales, in a still clearer
light, it should be observed, that, by the regulations
at Marseilles, all suspected goods are subject to what is
termed sereines; that is, a certain number of bales are
taken out of the hold, and, being opened at both ends,
are exposed to the air for two, three, or six days, by
way of trial, in order to see if any signs of infection
should appear among those employed in handling the
merchandise. When these have been aired, more or
less, according to circumstances, another parcel is
opened and exposed to ventilation in like manner:
so that, according to the burden of the ship, there may
be several of these sereines, each of several days duration.
In this manner, independent of accidental impediments
from wind and weather, in sending the goods
from the ship, it maybe supposed, were it at all necessary
to make the supposition, that the porters, not only
on the 23d of June, but on the 7th and 8th of July,
were infected upon opening some new bales. As to
the porter being infected by goods from another ship,
Dr. Pye thinks it impossible, because the ship had been
twelve days in port, and the goods must have been
eight or nine days in airing and purifying: had he
been acquainted with the practice of the sereines in
quarantine, he would have been at no loss to make the
accident agree exactly with his notion of the infectious
aura. . . . The plain matter of fact, as it stands in
the journal, is this, that six porters, employed in purifying
suspected merchandise from the Levant, died
of the plague; and their death was followed by that
of the surgeon who attended them, and part of his
family.”
From this the reader will be able to judge how far the
question is decided in favour of the fact that the plague
at Marseilles was actually produced by imported contagion.
It seems needless to follow our author through
his investigation of those facts which his adversaries have
misrepresented; for these must of course be in his favour;
every misrepresentation by a disputant being plainly an
abandonment of his cause. Indeed the argument against
contagion at that time was properly but one, and is set
forth in no stronger language now than formerly. Even
as long ago as 1665 Dr. Russel quotes one Gadbury an
astrologer stating the difficulty as strongly, and giving a
solution of it as clearly, upon his principles, as the best
modern theorists can do upon theirs. “If the pestilence,
(says Mr. Gadbury) be infectious, and really catching
in itself, it must be so equally to all persons that
approach it, or that it approacheth; or else it must be
infectious to some particular persons only. If it be
infectious to all persons, or catching to all alike, then
all persons, that come into the sight or within the scent
of it, must necessarily be subject unto it. If not infectious
unto all, but unto some particular persons only,
I say then it ought not to be deemed or esteemed
infectious at all, at least not any more infectious than
are all other diseases, viz. small-pox, scurvy, pleurisy,
ague, gout, &c. since (though the notion of infection
be laid aside) there is not a person born into the world
that hath not at some time of his life (as his nativity
shall truly show) some one disease or other. Never
was any person subject to violent diseases, as plague,
&c. but had a violent nativity to show it, and e contra.”
The answer to this has been already given.—Let any
other cause than contagion or infection be supposed, and
the difficulty remains equally great. The probability is
in favour of contagion, rather than a general disposition
of the atmosphere, because in the latter case the disease
would, contrary to experience, begin in a great many
places at once; but the plague begins in such a secret
manner that we scarce know whence it comes. Like fire,
or a ferment in liquors, it diffuses itself far and wide, and
lastly, like an immense inundation, the source of which is
dried up, it seems to lose its power by extending too far,
and dies away altogether. We cannot penetrate into
the causes of those things, but, without any speculation
at all, we can observe that the disease falls upon people
of a certain constitution more than others, and this may
be of use in preserving ourselves from it, as shall be
explained in the next section.
It is still necessary to say something of the infection
spreading from one person to another, and being kept off
by refraining from communication with the diseased.
This indeed naturally follows from its proceeding originally
from the cotton: for as all the infected did not
touch this cotton, there can be no other cause assigned
from its spreading than by communication from one to
another; and, therefore, if such communication was cut
off, we should naturally think that the disease would not
spread. But, in opposition to this, we have already
quoted Dr. Moseley giving a long list of convents infected,
though they kept themselves strictly shut up. Dr. Russel
cites, in favour of prevention by shutting up, two
certificates, one by the bishop of Marseilles, the other
by the sheriff of the same place. To these he adds the
testimony of M. Langeron, who was actively employed
throughout the whole time that the plague continued,
first as a commodore of the gallies, and afterwards as
governor of the town and its dependencies. In opposition
to these, however, he takes notice of two passages
“in books of acknowledged authority,” which he is at
pains to answer; the one is from the Journal already quoted,
which says, “and what is unaccountable, those
who have shut themselves up most securely in their
own houses, and are the most careful to take in nothing
without the most exact precautions, are attacked there
by the plague, which creeps in no one knows how.”
The other passage is taken from the Relation Historique,
“that, in the height of the pestilence, the infection
penetrated into places which had till then remained
inaccessible; that monasteries and houses shut up in
the most exact manner were no longer places of security.”
To the former of these our author answers, that “from
the manner of stating the case, one would think that
all these religious had been close shut up, without any
communication with persons without doors; and this
was certainly intended by an author who has made
remarks upon it; but it will be found, upon looking
into the beginning of the very paragraph cited, that
the greatest part of them are represented as martyrs
who had meritoriously exposed themselves. Of the
twelve different orders mentioned on this occasion,
the Grand Augustines only are said to have kept in
their convent. But, supposing the Augustin convent
to have been actually shut up, and in that state infected;
it would by no means invalidate the instances
brought of the preservation of the convents, the certificates
concerning which were granted deliberately,
after all was over; whereas the journal, written from
day to day, marking circumstances rapidly as they
occurred, the author, amongst various other affairs, had
not always leisure or opportunity to examine minutely
into circumstances. It is in this light I am inclined
to consider the houses being infected which took in
nothing without the most exact precautions; and the
rather, because I met with several instances of the like
kind at Aleppo, in the houses of the Christian and
Jewish nations: but in the sequel it generally appeared
there had been some improper communication carried
on by the domestics, unknown to the family at
the time.”
“That the atmosphere, in a city so dreadfully circumstanced
as Marseilles, may become so highly
tainted as to convey the plague into houses shut up,
cannot confidently be affirmed to be impossible, by
those who hold mediate contagion; and the concurrence
of circumstances at that period in Marseilles, renders
it highly probable that such accidents happened.
But, in general, the pestiferous effluvia once emitted
into the air, do not appear to operate at any great
distance from their source; and M. Deidier asserts,
that two monasteries (from their situation, one near a
burial ground, the other near a pest-house) very dangerously
situated, remained nevertheless untouched,
which he thinks an argument against infection being
conveyed by the air.”
From this long and contested account of the manner
in which the plague was received into Marseilles, we see
how very difficult it must be to come at a true state of
facts, when a number of people think it their interest to
misrepresent or conceal them. The limits of this treatise
will not allow us to follow our author through the
numerous details of misrepresentations and unfair methods
which the adversaries of the doctrine of contagion
have made use of to establish their opinion: neither
shall we enter into any discussion concerning the origin
of other plagues, as we should in them find the same
opposite kinds of evidence without such documents for
distinguishing the true from the false as Dr. Russel has
produced in the case of Marseilles. A single fact only,
mentioned by Mr. Howard in his Treatise on Lazarettos,
shall be related, and which, if allowed to be fact,
decides the question as effectually as a thousand.
“When the plague raged at London in 1665, it was
conveyed to the remote village of Eyam near Tideswell
in Derbyshire. In this place it broke out in September
1665, and continued its ravages upwards of a year,
when two hundred and fifty of the inhabitants had
died of it. The worthy rector, Mr. Mompesson,
whose name may rank with those of Cardinal Borromeo
of Milan, and the good bishop of Marseilles, at
its breaking out, resolved not to quit his parishioners,
but used every argument with his wife to quit the infected
spot. She, however, refused to forsake her husband,
and is supposed to have died of the plague.
They sent away their children. Mr. Mompesson constantly
employed himself, during the dreadful visitation,
in his pastoral office, and preached to his flock
in a field, where nature had formed a sort of alcove
in a rock, which place still retains the appellation of
a church. He survived, and the entries in the parish
register relative to this calamity are in his own hand
writing, viz.
In 1665, |
Sept. |
Died 6 |
1666, |
May |
Died 5 |
|
Oct. |
22 |
|
June |
20 |
|
Nov. |
5 |
|
July |
53 |
|
Dec. |
7 |
|
Aug. |
78 |
1666 |
Jan. |
3 |
|
Sept. |
14 |
|
Feb. |
5 |
|
Oct. |
17 |
|
March |
2 |
|
Nov. |
1 |
|
April |
12 |
This plague is said to have arisen from a box of
clothes sent from London while the distemper was at its
height in that city. But whether this be admitted or
not, it cannot well be supposed that in a small village
there could either be a peculiar constitution of the air,
collections of filth, immoderate heat, cold, or in short
any general cause from which a plague could be supposed
to arise, that would not have affected the country
for a great way round. How then came this insulated
spot to be so violently affected, except by contagion?
No matter whether by clothes or any thing else. The
very particular manner in which the numbers who
died are recorded, leaves no doubt as to the fact of the
distemper having been there; neither is it possible to
account for its rise on any other principle than contagion.
Mr. Howard, previous to his going abroad, had been
furnished, by Dr. Aikin and Dr. Jebb, with a set of
queries relative to the plague, to be put to the physicians
in the different countries through which he travelled.
This commission he executed with great fidelity
and exactness. The physicians to whom he proposed
them were, Raymond of Marseilles, physician;
Demollins of do. surgeon; Giovanelli, physician to the
lazaretto at Leghorn; They, to do. at Malta; Morandi,
physician at Venice; Verdoni, at Trieste; Jew physician
at Smyrna; Fra. Luigi di Pavia, prior to the hospital
of San Antonio at Smyrna. The questions proposed
were as follow:
1. Is the infection of the plague frequently received
by the French?
Though this was not asking in direct terms whether
the plague is infectious or not, all to whom it was proposed
seem to have viewed it in this light, Raymond of
Marseilles only excepted, who answered directly, “Sometimes
it is.” All the rest, except Giovanelli, agreed that it
might be communicated by the touch, or by the breath.
Verdoni gave an instance of its being communicated by
a flower which three persons smelt at; two remained
free, but the third sickened and died in twenty-four
hours.
2. Does the plague ever rise spontaneously?
In this Verdoni alone answered positively in favour of
the spontaneous rise of the plague. They spoke ambiguously.
3. To what distance is the air infected? How far
does actual contact, wearing infected clothes, or touching
other things, produce the disease?
To this question Verdoni answered in a manner seemingly
inconsistent with his former answer; allowing not
only that the plague was infectious, but that infected
things might communicate the disease after an interval
of many years. All agreed that the strength of the infection
was greater or less according to circumstances;
the distance at which it could act was likewise uncertain.
Raymond said that the sick might be safely conversed
with, across a barrier, at a few paces distance; the Jew
said at two ells distance, provided the chamber windows
be not all shut. Giovanelli said it had been proved that
the infection did not extend beyond five geometrical
paces. The touch of infected clothes, or drawing in
the breath of the sick, was looked upon by him and
Fra. Luigi to be very dangerous.
4. What are the seasons in which the plague chiefly
appears; and what is the interval between the infection
and the disease?
To this it was answered by Raymond, that the two
solstices are the times in which it has least power. The
others agreed that hot and moist weather was favourable
to its ravages; the spring, summer and first month of
autumn are dreaded. These circumstances, however,
must be variable in different countries. As to the time
in which the infection shows itself, the answer was various.
According to They, it “sometimes acts slowly,
sometimes like a stroke of lightning.” According to
Verdoni, “the disease generally shows itself at the instant
of touch, like an electrical shock.” Sometimes the
infection will be communicated from a sick person to a
sound one, who without any disease may communicate
it to a second, and that second to a third, in whom alone
it would become active.
The other questions, relative to the symptoms, prevention
and cure of the distemper, will be taken notice of
in the course of the treatise. In the mean time having
discussed, with a prolixity almost exceeding our bounds,
such preliminaries as seemed most likely to throw some
light on the nature of the distemper, we shall now proceed
to the medical history of the plague, as we find it
laid down in different authors.
Though this distemper has most frequently been accounted
a fever in the highest degree, yet, as we have already
noticed, it seems to be essentially different.99 The
testimonies there quoted are sufficient to establish the
fact; and, were it needful, many others might be brought
from authors both ancient and modern. In the plague
said to have taken place in the days of Romulus,100 Plutarch
relates, that the people died without any sickness.
To this very ancient testimony we shall add that of Dr.
Patrick Russel, who closes the account of his first class
of patients with the following paragraph: “That the
plague, under a form of all others the most destructive,
exists without its characteristic eruptions, or
other external marks reckoned pestilential, can admit
of no doubt; and it is to be regretted that mankind
have so often, from the absence of these, been betrayed
into errors of fatal consequence on its first invasion;
at which early period human prudence can only be
exerted in the way of defence with any probability
of success.”
The symptoms of this fatal disease were sometimes a
sudden loss of strength, confusion or weight in the head,
giddiness at intervals, oppression about the præcordia,
dejection of spirits, taciturnity, an anxious aspect, but
without any symptoms of fever. In these, death ensued
within twenty-four hours; some were said to have died
within a few hours, but our author saw none of these,
and is inclined to doubt the truth of the accounts, having
in several instances, where this is said to have happened,
found upon inquiry that matters had been inaccurately
stated, and that the patients had really been ill
one or two days.
In others the disorder was more perceptible. In a
few hours the eyes became muddy, the surface of the
body cold, with drowsiness, lethargy, and pain at the
heart. In the progress of the distemper they frequently
lost the power of speech, the skin seldom recovered its
warmth, or, if it did, it was only by irregular flushings.
The pulse sometimes remained nearly in its natural state,
but was, for the most part, low and quick. They were
“by turns delirious, confused and sensible, but the comatose
disposition was most prevalent. Towards the
end they suffered extreme inquietude. Vomiting in
some occurred the first night; in others a diarrhœa
next day; both accelerating the fatal period; but
these symptoms were less frequent than in some of the
other classes. Buboes appeared only in a very few
who survived the third day. . . . The total absence
of buboes in such patients as perished suddenly I have
no doubt of, nor of their being in general very rare in
others of this class; though I suspect that the buboes
might sometimes have been concealed, where the disease
ran out to the fourth or fifth day, and for the
same reason that the reports concerning the state of
the corpse were sometimes not true. . . . It was
very rare to find suspicious marks of infection on the
bodies [of those who died within 24 hours]. . . .
Carbuncles were seldom visible till the month of May,
which was later than this form of the disease. It prevailed
chiefly at the rise of the plague in 1760, and
its revival in the two succeeding years, decreasing as
the distemper spread; and though they were found
dispersed in every stage of the pestilential season, yet
the number of this class was proportionably small,
compared with that of others. Petechiæ, vibices, or
broad, livid, roundish spots, occurred sometimes, but
were not common, and the two latter were seldom visible
till after death.”
This account of the most malignant form of the pestilence
differs considerably from that of Dr. Hodges, who
seems to think that the tokens, as he calls them, very
generally were to be found on the bodies of those who
died suddenly. He mentions indeed a young man who
was suddenly seized with a violent palpitation of the
heart, and thus continued till his death, which took
place in a few hours. In this case the Doctor supposed
that there might be a carbuncle broke out on the heart.
Dr. Russel has considered the description of the tokens
given by Dr. Hodges, and compared it with that of
others called by Diemerbroeck maculæ mortis, spots or
tokens of death; and by this comparison it appears that
the former has spoken somewhat indistinctly on the subject,
confounding two different kinds of eruptions together.
Dr. Hodges, however, as we have already seen
(p. 10) asserts, in his Loimologia, that the tokens rise from
within, and are broadest at their bases, where he also supposes
the pestilential poison chiefly to lie. To the same
purpose, in his Letter to a Person of Quality he says,
“The tokens have their original and rise from within,
and afterwards externally show themselves; which is
evident, because the basis of them is larger than their
outward appearance, and the internal parts are found
very often spotted, when there is no discoloration
visible on the skin.” Dr. Russel, after quoting Diemerbroeck,
makes the following observations: “The
author (Diemerbroeck) is diffuse on this subject, and
thinks it a mistaken though prevalent notion, that the
maculæ are merely superficial in the skin, proceeding
from putrefaction, ebullition, &c. in the blood or humours:
on the contrary he affirms, they arise from the
internal parts, even the periosteum, broad at the base,
and tapering to their termination in the skin, being
produced by the extinction and extravasation of the vital
spirits. Now (says Dr. Russel) this answers exactly
to one species of the tokens described by Hodges,
which therefore may be reckoned the same with the
maculæ mortis, and was probably the only one observed
at Nimeguen,” &c. On the same subject he quotes
a book entitled Medela Pestis, in which the author says
that by careful dissection the tokens may be traced half-way
deep in the flesh, and some, in the muscles of the
breast, have been followed by the incision knife even to
the bone. By the directions given by authority to the
searchers in 1665, they were ordered to look narrowly for
these tokens, which were described as “spots arising on
the skin, chiefly about the breast and back, but sometimes
also in other parts. Their colour is something
various, sometimes more reddish, sometimes inclining
a little towards a faint blue, and sometimes a brownish
mixed with blue; the red ones have often a brownish
circle about them, the brownish a reddish.”
On the subject of tokens Dr. Hodges further observes,
that they differed also in their degrees of hardness,
some being easily penetrated with a needle or
penknife, while others, more callous or horny, were
penetrated with more difficulty. They so strongly
resembled warts, that they could scarce be distinguished
from them; and Dr. Hodges himself was often obliged
to have recourse to a needle for this purpose. They
seemed hard to the touch, not unlike kernels under the
skin, the superfices being smooth. “When I essayed
to prove some of them (says he) I found them almost
impenetrable.” Another very remarkable circumstance
relative to them was, that they were often quite insensible,
and this distinguished them from the carbuncle,
which is always very painful. Hodges also remarks,
that a quick sensibility in the skin was always a good
sign, and those that went no farther than the skin would
sometimes slough off.
Along with these tokens we can scarce doubt that
petechiæ and vibices made their appearance. The former,
even in the inferior degrees of the distemper, were
dangerous, the latter always fatal, never appearing till
the patient is within a few hours of death, sometimes indeed
not till death has taken place. Of the petechiæ Dr.
Russel says, that for the most part they predicted death,
but not without exception. Such as he observed were
round, somewhat smaller than a recent flea-bite. They
were distinct, few in number, and scattered irregularly
about the breast and mastoid muscles. When they did
not appear till the approach of death, they were from
the first livid, or very dusky; but if they appeared early,
they were of a less deep colour, changing afterwards to
livid. Hodges speaks of them as deeper coloured than
the spots of malignant fever, not fixed in any particular
spot, sometimes few, but commonly very numerous; the
colour sometimes red or purple, sometimes yellow, and
sometimes livid or black. From Gotwald, Russel quotes
a description of these spots, which he divides into four
species. 1. Reddish, like flea-bites, soon growing brown
or black; appearing on all parts of the body except the
face. 2. In the form of lentils, spreading like the former
all over the body; ruddy at first, but in 24 hours growing
dark or ash-coloured. 3. Large brown spots, scattered
here and there, sometimes intermixed with the lentil kind.
4. Not unlike the measles, spreading all over the body,
rising afterwards in small blisters without any matter,
vanishing about the fifth day. Russel also takes notice
of a species of petechiæ which were very numerous, confluent,
and of a dark red or dusky colour and irregular
figure. These were sometimes remarked in the interstices
of the former. Such instances occurred but rarely.
The vibices were much larger than the petechiæ.
Gotwald says that they covered the face as high as the
nose, and from thence spread to the forehead, disfiguring
the patient in a frightful manner. They did not appear
till a short time before death. Often they appeared unexpectedly,
shooting up like lightning from the breast
to the face, in spots of various colours, blue, green, brown
and yellow. Diemerbroeck describes them as oblong
spots of a livid or black colour, like strokes drawn with a
pen; sometimes they were larger, the biggest resembling
the strokes of a whip. Russel takes notice of a kind of
marbled appearance which took place at the height of
the disease, or a few hours before death; the colours being
a faint blue, and darkish red, both more or less obscure
at times, but never bright. It was not permanent,
vanishing in one place, without leaving any trace, and
returning at short intervals. “The skin in various places
was sometimes deformed by narrow streaks of reddish
purple, or livid colour. When such took possession
of the face they gave a frightful appearance to the
countenance, and frequently made such an alteration
in the features, and so completely disguised the patient,
as to render him hardly knowable by his acquaintance.
A streak nearly of the same kind was sometimes observed
darting from the edges of the buboes and carbuncles.
The vibices or weals were much longer and
broader, and more exactly resembled the marks left in
the fleshy parts by blows or stripes; they were found
chiefly on the thighs, buttock, and back, and made
their appearance several hours before death, in some
cases, but in others not till after. Large blue or purple
spots, the maculæ magnæ of authors, were sometimes
observed with or without the vibices, a little
while before the patient expired, but most commonly
were discovered only on the corpse. Their figure in
general was round, sometimes irregular.”
Whether all these mortal signs appeared on such as
died very suddenly of plagues, and were by the English
writers confounded under the general name of tokens,
cannot certainly be determined. Dr. Russel saw none
who died within the twenty-four hours, and few who died
within thirty hours, so that we cannot from him expect
any particular account of the situation of those who
died suddenly. In general, however, he says, that “in
the most destructive forms of the plague, the vital
principle seems to be suddenly, as it were, extinguished,
or else enfeebled to a degree capable only for a short
while to resist the violence of the disease; in the subordinate
forms, the vital and animal functions, variously
affected, are carried on in a defective, disorderly
manner, and denote more or less danger accordingly.”
It seems probable therefore that in those who are suddenly
killed, the same effects take place in a short time which
are observed to take place after a longer space in those
who die gradually, buboes only excepted, which require
for their formation a longer time than is allowed to the
patient to live. Internal mortifications, or rather eschars,
are therefore to be suspected, and dissections have evinced
that this was really the case; but besides these there
was an appearance observed in the plague at Marseilles
which is not taken notice of by former physicians; viz.
a preternatural enlargement of the heart. M. Deidier
on that occasion communicated an account of nine dissections,
but of these only one had died without eruptions.
This was a woman of 40 years of age, who lived
till the third day. In her “the mediastinum101 was torn
towards the upper part; the pericardium of a livid colour;
the heart larger than in its natural state, by the
swelling of its ventricles; full of thick, black blood.
The liver was also very large, and of a livid colour, with
a carbuncular pustule on the side of the gall-bladder,
which was filled with very black bile.” In others
who had eruptions, and who of consequence we must
suppose to have lived longer, the enlargement of the
heart was still more remarkable. In one who lived
eleven days, the heart was of double the bigness, having
scarce any blood in the ventricles, whose cavities were
filled each with a large polypus, that on the right side
having dilated the auricle to the breadth of four inches.
The liver also was larger than ordinary, and the gall-bladder
full of a black and green bile. The appearances
were much the same in all the rest, but, as the time
they sustained the disease is not mentioned, we cannot
determine whether the enlargement of the heart took
place at the very first, or was only an adventitious symptom
after the fever had come on. Dr. Russel takes
notice that such patients as he attended complained
greatly of their heart. “A sense of oppression about the
præcordia (says he) which the sick were at a loss to
describe, was, in one degree or other, a constant attendant
on the plague, except in very slight cases of
infection; and where it came on early, or persisted in
a high degree, was always a dangerous symptom.
The sick showed how severely they suffered by their
perpetually changing their posture, in hopes of relief;
but, when asked where their pain lay, they either answered
hastily they could not tell, or, with a fixed, wild
look, exclaimed kulbi! kulbi! (my heart! my heart!)
This anxiety increasing as the disease advanced, terminated
at length in mortal inquietude, the patient,
for many hours, in the last stages, incessantly writhing
his body and limbs as if in agony. Though pain at
the heart was often conjoined with the symptom just
mentioned, and by the sick seemingly blended together,
it appeared to be different, and to exist separately.
They often exclaimed as in the other, my heart! my
heart! pointing also towards the scrobiculum cordis,
but then would add eujani kulbi, my heart pains me;
or naar fi kulbi, my heart is on fire.” This last pain
the Doctor supposes might have its seat in the upper orifice
of the stomach; the extreme anxiety may be accounted
for from the enlargement of the heart; but as
neither of these symptoms took place in such as died in
a very short time, we must be apt to consider this enlargement
not as any primary and essential symptom of the
disease, but as one which takes place when the vital powers
are able to oppose for some considerable time the cause
of the disease.
In his account of the origin of the plague, Dr. Russel
takes notice of the opinion that, at the communication
of the infection, the sick were sometimes sensible of
having received it. This has been observed by Dr. Lind
in malignant fevers; it has also been observed in plagues,
as we have seen from Dr. Hodges, Verdoni, and others;
but Russel says he never saw any instance of this. He
owns, however, that he has seen instances of the disease
quickly succeeding a panic fear of being infested. “In
cases (says he) where the disease was not discovered to
be the plague, till upon the eruption of buboes after
two or three days, I have known several persons who
had, till then, without the least suspicion, frequented
the sick, struck suddenly with a panic, and imagine
themselves ill. They felt shooting pains in their
groins, confusion in the head, and a loathing. Though
in some these complaints were merely imaginary, and
soon vanished, in others they proved real; the symptoms
increasing, and being followed by eruptions. In
such cases I suspected the latent infection to have
been excited by terror.”
In the instance formerly quoted from Dr. Guthrie at
Petersburg, we have a notable example of this sudden
seizure by a stroke. His information was derived from
the physician-general of the Russian army. This gentleman
assured him, that “he had seen men, in apparent
good health, instantaneously drop down, as if shot
by a musket ball, by the sudden action of the pestiferous
miasma, and upon duty again in 24 hours, perfectly
recovered by the operation of a strong vomit.”
Whether or not these men felt any stroke at the instant
of their falling we are not told: possibly it might be
only a syncope very common in the plague, which took
place at the very first invasion. Russel informs us, that
“the sudden loss of strength, and disturbance of the
functions attributed to the brain and heart, are reckoned,
in a particular manner, symptoms of the plague.
In their highest degree they distinguish the most fatal
forms of the disease; and, under different modifications,
adhere to all its varieties. . . . The early appearance
of faintness was very remarkable in the
plague,” &c.
Thus we see that the plague attacks without fever in
two different modes; one, by attacking and destroying
the solid parts of the body, the other, without any disorganization
of the body, attacking the vital principle
itself, or rather the blood, from which this principle is
derived, so that a temporary suspension of all the functions
ensues. The analogy between the cause of pestilence
and those visible substances called poisons, is very remarkable
in some things, though in others it totally fails.
In the Medical Repository102 we have a dissertation upon
this analogy by Dr. Edward Miller. He observes, that
this analogy has been generally overlooked, chiefly on
account of the invisible nature of the aerial poison, and
the suddenness of death from poisons, more frequently
than from pestilential diseases. This he accounts for
from the largeness of the dose of poisons compared with
that of contagion; “but (says he) by diminishing the
quantity to an appropriate amount, these noxious substances
(the poisons) may be made to exhibit the
course, duration, and nearly all the phenomena, of
what is called a malignant fever. But, above all, the
attention of physicians has been diverted from this
analogy between miasmata and poisons, by the febrile
part of the character which generally belongs to pestilential
diseases, and which, in common apprehension,
is constantly connected with them. Yet these diseases
are by no means universally accompanied with what
is strictly called fever. There is often a degree of
virulence in the Asiatic plague, in the yellow fever,
and in all the other forms of pestilential and malignant
diseases, which altogether transcends the process of fever,
and extinguishes life in a more summary manner.
In the worst cases both of poison and pestilence, the febrile
part of the symptoms excites little attention.”
Our author does not say in what this virulence consists.
In the cases of those who die with the tokens upon
them, the cause is plainly within the body; the destroying
power acting with greatest efficacy below the skin in
the soft substance of the flesh. Where the patient is
suddenly seized in the manner described by Dr. Guthrie,
the cause seems to be something foreign to the body
suddenly inhaled, the effects being similar to those of
fixed air when drawn in by the breath, and of consequence
easily expelled by a vigorous action of the powers
of the system. Guthrie observes, that, in such cases, it
seems “as if the contagious matter existed in a very
loose state in the first passages at the beginning of the
disease.”
In the production of those tokens mentioned by Dr.
Hodges, we know that there must have existed in the
body a certain cause capable of totally destroying the
parts, and reducing them to an hard eschar, similar to
that produced by fire or by a caustic. As we are unacquainted
with any thing capable of producing this effect
but fire, we can attribute the origin of these tokens to
nothing else but the emission of the latent heat of both
the solids and fluids which compose these parts, and
their consequent transmutation into an hard, and as it
were charred, substance. That such an emission of latent
heat does in some cases take place is evident from
the production of a great quantity of sensible heat when
certain substances are mixed together. Thus, upon
mixing together oil of vitriol, oil of turpentine and
strong spirit of nitre, the whole mixture will take fire
and burn violently, though two of the ingredients, viz.
oil of vitriol and spirit of nitre, are by themselves incapable
of being inflamed. In like manner if strong spirit
of nitre be poured upon oil of cloves or sassafras, the
mixture will burst out into a violent flame. Water
poured upon quick lime occasions great heat, and seems
in great part to be converted into a solid substance;
for only a small part evaporates, and the slaked lime
falls into a powder to appearance perfectly dry, and
from which the moisture cannot be expelled without a
very violent fire. In this case Dr. Black is of opinion
that the heat comes from the water, which, as we have
already seen, contains a great quantity of it in a latent
state. But, according to his experiments, the emission
of 135 degrees of heat is sufficient to reduce water to a
state of solidity; and the heat of lime when slaking is
so much superior to this, that ships have frequently been
set on fire by it. We must therefore either say that
water in certain circumstances can part with much more
than 135 degrees, or that the lime itself emits part of
the heat it contains. This last indeed seems to be the
more probable supposition of the two; for though
fluids contain more heat in proportion to their bulk than
solid bodies, we have no reason to suppose that the latter
contain none at all: on the contrary the experiments
formerly mentioned, especially those made by Count
Rumford, show that they are furnished with an almost
unlimited quantity.
The cause of the most violent kind of plague then we
must suppose to be something received into the body,
which in a certain time, probably sooner or later according
to the strength of the contagion, disposes to an
irregular emission of its heat, which coming by a kind of
explosions, or, as Dr. Hodges calls them, blasts, produce
those eschars which have been called tokens, and seem to
be no other than partial combustions, by which the parts
affected are reduced to a state of charcoal, or nearly so.
In assigning this cause for the most deadly kind of
plague, we must naturally ask the question, how can all
this take place without any pain? for of those who died
in this manner, many felt neither pain nor uneasiness till
within a few moments of death. This can only be
accounted for by the sudden and perfect destruction of
the parts, which did not allow time for any sensation of
pain to take place; and indeed in the application of
caustic for an issue, the patient often feels but little pain.
It is impossible to avoid perceiving a very strong connexion
between this kind of plague and the dreadful
cases of spontaneous combustion related p. 182–186.
In the case of the priest indeed the fire seems to have
come from without, though even this cannot be ascertained
beyond a doubt; but in those who were absolutely
consumed to ashes, it seems equally probable that it may
have arisen from within; and as none of the unfortunate
persons seem to have made any noise or struggle, the
priest alone excepted, it seems probable that the first
attack had deprived them of all sensation, and that, notwithstanding
the terrible ideas with which such extraordinary
occurrences must have inspired those who saw
them, the sufferers may have died without feeling any
pain. The priest seems to have felt nothing after the
first stroke.
Should this cause be admitted (indeed whether it is
admitted or not) we see that it is in vain to attempt to
solve the phenomena of pestilence by the doctrine of stimuli,
excitement or debility. There is no degree of stimulus,
fire exepted, which can convert part of the body
into an hard eschar, neither can it be done by any degree
of debility or exhaustion. Besides, the irregular
manner in which these eschars are scattered up and down,
shows that the cause has not acted from a regular diffusion
all over the body, but in a number of insulated
spots, between which the connexion can by no means
be traced. In all pestilential eruptions indeed the action
of fire seems to be very perceptible. Gotwald mentions
his having observed in two patients what he calls papulæ
ardentes “burning pimples,” which Dr. Russel supposes
to be a modification of carbuncular pustules. Gotwald
calls them also fire-bladders, and says that they were as
broad as a shilling, of an irregular shape, and the skin
seemed as if shrivelled with fire. The carbuncle itself approaches
much to the nature of the eschar, and is attended
with violent heat in the adjacent parts. Gotwald, who
gives an account of the plague at Dantzic, distinguishes
the carbuncle into four kinds, (to be afterwards described.)
Of these he says in general, that they all burn very
violently at first, &c.
From all these accounts it seems plain, that in the
plague there are partial discharges of heat, from some
cause, upon various parts of the body; and that, in many
instances, this heat destroys the texture of the parts
entirely. When this is done instantaneosly the patient
feels no pain, but if more gradually, the pain is excessive,
as in the case of buboes and carbuncles; which the
Journalist of the plague year in London informs us
were attended with such horrid pain as to make the patients
cry out in a lamentable manner. This extraordinary
heat must either come from without or within, and
we have all the reason in the world to believe that it
comes from within. Mr. Hunter, in his Treatise on the
Blood, informs us that in a local inflammation there is
always an increase of heat in the inflamed part. Should
this heat arise, as it probably does, from an emission of
part of the latent heat, we may conclude, that such a
quantity might be emitted, as entirely to change the
texture of the parts. Thus mortifications or destructions
of those parts may ensue, of all kinds, from the
mild pus to the pestilential eschar.
In the effects of pestilential contagion we observe, if
not a superiority, at least a different mode of action from
what takes place in poisons. All these seem to act by
dissolving the blood, or infecting it in such a manner that
it supplies no sufficient quantity of animal spirits; of
consequence, the creature soon faints and dies. In the
plague, the blood does not appear to be much affected,
nevertheless it emits, in various places, certain explosions
which convert the parts into an eschar. Poisons always
seem to produce the petechiæ or purple spots which
sometimes appear in the plague. In Dr. Miller’s Treatise,
already quoted, we find, among the symptoms occasioned
by arsenic, “red or dark spots appearing on the
skin, and rapid putrefaction, which renders speedy interment
necessary.” Herein it differs from the plague,
for the bodies of such as die of that distemper are not
more liable to speedy putrefaction than others. Of the
vegetable poisons he also observes, that, “after death,
sometimes before, livid spots are observed on the body,
the appearance of the blood is dark and dissolved, and
putrefaction speedily takes place.” Of animal poisons—“The
bite of the poisonous serpents is generally
followed by tumour, and livid colour of the part bitten,
extravasation of dark coloured blood into the adjacent
cellular membrane, nausea and vomiting, sudden
prostration of strength, paralysis of the limbs, convulsions,
yellowness of the skin, hæmorrhages, &c.
Livid appearances of the body, a dark coloured and
dissolved state of the blood, and a rapid putrefaction,
are observed after death.”
From all these accounts, however, it is plain, that,
whatever may be the analogy between the action of poisons
and malignant fevers, they do not in any manner
operate like the contagion of the true pestilence. Of
this the constant effect is to produce buboes, carbuncles,
and other eruptions, resembling much more the effects
of fire than any thing else; or, if the patient is cut off
without the appearance of these, similar effects are observed
on the internal and vital parts. Dr. Miller’s conclusion
seems therefore liable to exception; in which he
says, “that only the lighter cases of pestilence are unlike
the effects of poison, but that, in proportion to the degree
of malignity, the resemblance grows stronger.”
It doth not appear that any poison hath produced one of
the characteristic symptoms of the true plague, or any
thing but what is common to animals dying of various
diseases, the red spots on the skin only excepted.
In the eighth volume of the Philosophical Transactions
abridged by Martyn, we have an account of a number
of experiments by M. Deidier and others, made upon
dogs into whose veins he injected, or poured into wounds
made in the miserable animals, the bile of people dead of
the plague at Marseilles. “The consequence was,
that they became melancholy, drowsy, and without
caring to eat. All of them died in three or four days,
with the essential marks of the true plague, declared
by buboes, carbuncles, and gangrenous inflammations
in the viscera, in the same manner as in the human
carcases from whence the bile was taken.”
The poisonous bile affected the creatures differently
according to the vicinity of the place of injection to the
heart. In the jugular vein it killed them in twenty-four
hours, injected in the quantity of a drachm to two
ounces of water. In this short time were brought on
gangrenous inflammations, the heart was stuffed with
thick and black blood, the liver was swelled, and the
gall-bladder full of green bile. This shows a very essential
difference between the action of the pestilential
poison and that of others; the former, in some parts of
the body at least, coagulates the blood; the latter, in
all parts, dissolves it.
In the crural vein (the vein of the leg) the effects
were less violent. In about an hour they became heavy.
In the former case they instantly became drowsy. In
the second experiment they contracted such a loathing
for food, that they would neither eat nor drink any
thing after the injection was made. On the third day
there appeared considerable tumours under the axilla
(the fore leg I suppose) and on their thighs, about three
inches from the wound. The wound itself turned
to a gangrene, and the creatures died usually on the
fourth day.
In another experiment the animal had convulsive
motions all over immediately after the injection, followed
by a lethargy. Next day a carbuncle appeared on the
great pectoral muscle on the right side. On the third,
a bubo appeared on the thigh, and the same day the dog
died. From the time of the injection he had neither
eat nor drank. On dissection the fore part of the breast
under the teguments was found entirely gangrened,
the inward parts and viscera full of black clotted blood,
the outward surface of the lungs was all purple, the heart
was swelled as big again as usual, and the four cavities
were full of black clotted blood. The bile of this dog,
injected into the crural vein of another, produced similar
symptoms, only the latter eat a little boiled meat,
which he vomited up again in two hours. He died the
third day, with the same symptoms of the plague as
the others.
The bile of people who died of ordinary malignant fevers
was much less powerful. A quantity (not mentioned
how much, but probably a drachm) mixed with four
ounces of warm water, was partly injected into the jugular
vein of a dog, and a compress soaked in the rest
of the liquor applied to the wound. He appeared heavy
and sleepy, and would neither eat nor drink till the third
day, when he did both willingly. On the fourth day
the compress fell off, the wound was found to be diminished
one half, and healed by degrees, the dog recovering
perfectly. In another experiment with the bile of
a patient who had died of a malignant fever, the dog not
only had about a drachm of it put into a wound in his
thigh, but was made to swallow some of it; notwithstanding
which he was not seized with any distemper,
and the wound healed in fifteen days. This bile was as
black as ink, in great quantity, and very thick. In the
other subjects it was of a deep green. In another experiment,
with the same bile applied on a compress, the
dog likewise escaped without any apparent disorder;
but in a third, the animal died in twenty-three hours,
though at first he had shown no sign of being affected,
only that he seemed to be thirsty, and drank with greediness.
On opening him his heart was found still to
beat with violence, and, after the beating ceased, no
blood was to be found in it, either in the auricles or
ventricles. “This liquor, crowded together in the great
vessels, appeared of a lively red, and very fluid, without
any of those concretions that we constantly observed
in those who died of the plague. Here appeared
neither external nor internal marks of the
plague.” The bile of a person who had died of an
erysipelas, injected into the crural vein of a dog, produced
no bad effect. A dog was killed by half a drachm
of Hungarian or blue vitriol injected into the jugular
vein. He died in universal convulsions: the heart was
full of grumous blood, reduced to a kind of thick pap, but
without any clots. The bile, applied to two wounds
in another dog, produced no bad effect.
From other experiments it appeared that even the
pestilential poison itself, taken into the stomach of dogs,
did not produce any deleterious effects. “A dog of
the Hospital of the Mail in Marseilles, who followed
the surgeons when they went to dress the sick, used
greedily to swallow the corrupted glands, and the
dressings charged with pus which they used to take off
the plague sores: he licked up the blood that he found
spilt on the ground in the infirmary; and this he did
for three months, being always gay, brisk, well, full
of play, and familiar with all comers.” The health and
briskness of this unfortunate dog proved his ruin, by
making him the subject of philosophical experiment.
A drachm of the pestiferous bile injected into the crural
vein, killed him in four days. He had a considerable
hæmorrhage from the wound the night before he died,
and he had also a disagreeable smell both while living
and after he was dead. Two other dogs, which had
swallowed a quantity of pestiferous bile, became heavy
and melancholy, refused their food, and showed other
signs of disorder; but all these went off in a short time,
and no signs of the distemper appeared.
These experiments induced M. Deidier to suppose
that the contagion of the plague lay only in the bile;
but the following experiment shows that the blood was
equally infected, and capable of communicating the
disease, and that of the most malignant species. It was
made by M. Couzier, physician to the infirmary at Alais,
and in the Philosophical Transactions we have the
following account: “I took a quantity of blood from
a person dead of the plague, and mixed it with warm
water, which mixture I attempted to inject into the
crural vein of a dog, but the end of the syringe being
too large to enter the vein, the experiment did not succeed.
This made me resolve to try to lay some of the
same infected blood upon the wound. This I accordingly
did, and covered it with a dressing, which the
dog got off in the night. I found the next morning
that the dog had licked the wound, and that he refused
his food. Towards night he began to bemoan
himself, and gave signs of an approaching death. The
next morning I found him dead, the wound being considerably
swelled and gangrened, and the edges round
the swelling were likewise gangrened.
“Upon opening the body, we found the liver something
larger than usual, with spots of a livid purple, as
in the bodies of persons dead of the plague. In the
stomach was found a quantity of black coagulated
blood, of the size of a hen’s egg. This in all likelihood
was what he had swallowed upon licking the
wound. The heart was very large, with a black grumous
blood in the ventricles, and the auricles were
turned blackish and gangrenous.”
This last experiment naturally brings to remembrance
those of Dr. Home at Edinburgh, in which he inoculated
the measles by means of the blood of patients ill
of that disorder. From the accounts he has given in his
treatise entitled Medical Facts and Observations, we can
have little doubt that his experiments succeeded, however
others may have failed. One thing, however, is very
obvious, viz. that if we mean to communicate a disease
by means of the blood, we must use a much greater
quantity than if we make the experiment with the matter
of an abscess. The case of contagious diseases seems
to be the same as in fermenting liquors. With a small
quantity of yeast we can easily induce fermentation in any
proper liquor, but, if we skim off the yeast, and use only
the pure fermenting liquor, we must use a much greater
quantity; and to inattention to this circumstance we
may with probability ascribe the difficulty which Dr.
Home himself met with in introducing the disease, and
the total want of success in others. In M. Couzier’s experiment
a considerable quantity must have been used,
as he says that in the dog’s stomach it equalled the size
of an hen’s egg. A much smaller quantity of matter
taken from a pestilential abscess is capable of producing
the disease in a human body, as is evident from the case
formerly quoted of that gentleman who inoculated himself
for the plague, and of which Dr. Guthrie gives the
following account: “This was Mathias Degio, one of the
surgeons of the hospital at Bucharest, a building appropriated
to the cure of the plague in the Russian army.
He, perceiving the gentlemen of his profession condemned
in a manner to death, if punctual in the discharge of their duty 103
had the resolution to inoculate himself for the plague, in
the full confidence of its efficacy, and ever afterwards
found himself invulnerable, whilst his companions
around him were falling victims to its fury. He produced
the disease by inserting, with the point of a
lancet, under the epidermis of his arm, matter from a
pestiferous abscess, and followed the cold regimen observed
in the small-pox, as he had imitated its mode
of inoculation. On the fourth day of the puncture
the fever declared itself, and he, being perfectly devoid
of fear, got through the disease without feeling more
inconvenience than if it had been that which he imitated.
He drank freely of cold water, with vinegar,
or a little wine, and kept generally out of doors. This
beverage was the only thing that had the appearance
of medicine,” &c.
From a careful attention to all these histories, it is
plain that the plague is naturally an eruptive disease, as,
in all the animals in which it was artificially brought on,
eruptions took place, provided the life of the creature
was sufficiently prolonged to allow them to come out.
Dr. Russel says, that, from his diary, he noted down
the cases of two thousand seven hundred patients, all of
whom had eruptions of one kind or other. In this it
agrees with the small-pox, which Dr. Mead justly considers
as an inferior kind of plague. In the latter,
however, the eruptions seem to resemble those called by
Dr. Hodges the tokens, only that the cause which produces
them is less violent in its nature; but why the
eruptions of the small-pox should be in distinct pustules,
and not one continued boil all over the body, is undoubtedly
inexplicable on any theory whatever. The
same is true of the plague. No man can explain why
the tokens, for instance, instead of being collected into
one great eschar, are dispersed into small distinct pieces;
or why, instead of buboes in the groin and armpit, or
instead of carbuncles in different parts of the body, there
should not be a single one equivalent in bulk and power
to them all. This appears similar to the phenomena of
rain, hail or snow, which fall in distinct drops, fluid or
congealed, or in flakes, instead of being equally diffused
all over the spot on which they fall. In the latter case
we say that the phenomenon is occasioned by electricity:
we may say the same, if we please, of the small-pox and
plague, with equal emolument.
From the accounts we have just now quoted, it appears
that there is between malignant fevers and the
true pestilence a very essential difference; the latter
tending to thicken the blood, the former to make it
thinner. In this respect therefore the poisons seem to
resemble malignant fevers very considerably; for M. Fontana
observed that by mixing animal poisons with blood
drawn from a vein, it was prevented from coagulating.
In the instance above related where a dog died in consequence
of bile injected into his veins from one who
died of a malignant fever, the blood was found extremely
fluid. In some who died of the hospital fever, Sir
John Pringle informs us, that suppurations had taken
place in the brain; but in the true plague the tendency
to mortification always prevailed above every thing.
Lastly, that the plague proceeds from too great a
quantity of heat, either emitted from the body itself, or
some how introduced into it, seems to be pretty plain
from the effect it has of augmenting the venereal appetite
to an almost inconceivable degree. This was taken
notice of in the plague of Marseilles, and indeed in many
others. Russel quotes two remarkable passages to this
purpose; one in a plague at Genoa, the other in Messina.
“Amidst so many dreadful fears and terrors, amid so many
fetid and putrefying bodies, amid the shrieks, the sighs
and the groans of the sick, what would you have
expected? That the people, struck with dread and
horror, remained sad, modest and quiet. You are
mistaken. They sung, played on instruments, danced,
intrigued, and Genoa never was seen so shameless,
debauched, and disorderly. I have said before, that
God in this plague gathered in a harvest for heaven;
but it seemed to be also a vintage for the lascivious of
of the earth. If not so, how came so many marriages
to be celebrated in the Lazaretto of Consolation, and
that so many women, without shedding a tear for the
death of their husbands, immediately entered into new
engagements? One day, in particular, five marriages
were performed, four of the bridegrooms being buriers
of the dead, and dressing themselves and their brides
in clothes stripped off from the bodies of the deceased.”
On the plague of Medina he quotes the following extract
of a letter written by a gentleman who resided in that
city during the plague in 1743. “It has always been
observed, that, after every plague, those who recover
are addicted in an extraordinary degree to lewdness
and incontinence, which was surprisingly visible at
Messina, and carried to such a degree of frenzy and
bestiality, that many were known to violate the bodies
of dead virgins!”
That an extraordinary propensity to venery may be
produced by introducing into the body a quantity of
heat, admits now of a kind of demonstration from a fact
mentioned by M. le Roy concerning phosphorus.104 This
substance is exceedingly apt to take fire on the application
of a small degree of heat, and even by slight friction.
It is now introduced into the materia medica, and is
found to be a very powerful medicine, though dangerous
on account of its inflammability, the heat and air contained
in the human stomach being sometimes sufficient
to set it on fire. The taking such a substance into the
body therefore seems not much different from taking
actual fire into it; and indeed M. le Roy mentions the
case of a woman who had taken only a single grain, and
who he says had been recovered, by it, from a putrid
fever, but died suddenly from some imprudence. In
this woman the whole substance of the body was found
luminous upon dissection, and the hands of the operator
continued luminous even after being washed. M. le Roy,
having taken three grains of this fiery substance, found
himself extremely incommoded by it for some hours,
and was obliged to drink great quantities of very cold
water. Next day he found his muscular powers amazingly
increased, and had an almost insupportable venereal
irritation. This we see was the consequence of throwing
into the body a quantity of heat from without; but if
the body itself emits that heat which it invisibly contains,
the effects must be the same as though an extraneous
quantity had been thrown into it. Neither are we
to imagine that the quantity of heat contained in our
bodies is small or inconsiderable; for we have already
seen that heat consists in the efflux from any substance,
of an invisible and most subtile fluid, in all directions.
When this flux is gentle, the heat is moderate, but in
proportion to the activity of the discharge, the temperature
becomes hotter and hotter, and if very violent,
the cohesion of the parts is dissolved entirely, and the
substance is said to be on fire. There is required therefore
only some cause to begin the emission of this fluid;
for as soon as this begins, the immense quantity with
which we are surrounded, will supply more in abundance,105
and continue so to do, as long as the original cause
subsists, or until the substance can no longer bear the
power which operates upon it.
From this view of the causes of the plague, and from
the facts which have been laid down concerning it, we
cannot help perceiving a very strong similarity between
the plagues mentioned in the Old Testament and those
which still exist in the world. In one of the passages
formerly quoted it is called an inflammation, an extreme
burning; and from the testimonies of different authors
above quoted, it is plain that the disease still deserves the
name bestowed upon it in the sacred writings. From
the account given of its proximate cause, it is plain that
plagues of all degrees of intensity may take place, from
absolute accension of the body, and its reduction to ashes,
to the mildest state of the disease, in which the patient
is not confined to his bed; and all this from the
single principle of emission of heat from the body itself.
It likewise appears that there may be either in the body
itself, or in the element which surrounds it, such a constitution
as will dispose that element which is the natural
and immediate preserver of our life, suddenly to attack
and destroy it, of which the case of the Italian priest
is a most remarkable instance. In other cases, such as
the Italian lady, and the woman at Coventry, the body
itself seems to have given out its heat, though this could
not be done without a concurrence of the surrounding
ethereal fluid. In a stage still lower, the body is partially
consumed, or rather partly charred into a kind of cinder,
as where the tokens are produced; and when the
cause acts with still less violence, a fever is produced.
In the Old Testament we find these different kinds of
plagues very distinctly mentioned. In some cases the offenders
died by actual fire, which either struck them
from without, or was kindled within their bodies. In
others, they seem to have died by that very deadly kind
of plague of which we have already said so much, which
kills in a few hours. This was probably the plague
which destroyed the army of Sennacherib, and this in
the tenth chapter of Isaiah is by some thought to have
been prophesied of under the title of a burning like the
burning of a fire.
Of these things I the rather take notice, as I perceive,
in a late oration, not only the doctrine of the plague being
propagated by contagion severely ridiculed, but the
scripture itself treated in a most indecent and scandalous
manner. “In the earliest ages of the world (says he)
when ignorance and superstition led men to attribute
all extraordinary phenomena to the direct agency of
supernatural beings, pestilence was supposed to be
immediately imported from heaven. This is the opinion
which appears to have prevailed among the ancient
Hebrews, and may be ranked at the head of the
catalogue of absurdities on this subject. The dominion
of prejudice over the minds of that ignorant and
obstinate people appears in this instance particularly
striking. Such was the depth of their blind bigotry
in favour of the healthfulness of the globe they inhabited,
that they would seem to have considered it as
even superior to that of the celestial regions. Hence,
unwilling to believe that their favourite earth could
give origin to an evil so dreadful as the pestilence, they
imported the seeds of this calamity from the more unhealthful
climate of heaven!!”
In this extraordinary paragraph we find the matter so
much misrepresented, that every vestige of truth is swallowed
up in it. The Hebrews believed that they were
under the immediate inspection and government of the
Deity; a doctrine which, however our author may disbelieve,
he cannot disprove. But, notwithstanding this
immediate inspection and government, the Deity never
did bring upon them any plague but by the intervention
of natural causes. The agents which he had originally
created were sufficiently able to execute his purposes.
The Creator never employed any power but what already
existed in the world, and the power that he generally
did employ was fire. This agent he directed to
exert its force in such degrees as he pleased, and against
whom he pleased. It is a mistake to think that miracles
were immediately the effects of supernatural power. They
were all accomplished by the very powers which exist in
the world at this moment, only these powers were by the
Creator at particular times directed to act in a manner
that they would not have done had they been left to the
mechanism of their own nature. When we read therefore
of people being consumed by fire from the Lord,
there was neither importation of fire from heaven nor
any where else; the element exerted its power on these
particular persons, either by lightning proceeding from the
cloud which represented the Deity, or their bodies
threw out the latent heat which they contained, and
consumed of themselves. That in cases of this kind
there was no importation supposed, is evident from an expression
used about bringing water from the rock. It is
not said that the water fell from the stars, or came down
with the tail of a comet, but that the rock gave out the
water which it previously contained. At the present
day the same powers exist, and sometimes produce the
same effects that they did in former times, with this difference,
that now, having no intelligent agent to interfere
with their natural mode of action, they exert their
force indiscriminately, and as the mechanism of their nature
happens to be stimulated, they destroy every thing
promiscuously before them. In all this I cannot perceive
the smallest absurdity, or any thing but what a reasonable
man may indeed must believe, if he makes use of
his reason. As to the causes which Dr. Caldwell so much
insists upon, viz. filth and corruption, it is extremely
probable that (while the Israelites were in the wilderness)
these had no existence. By their law they were enjoined
such frequent ablutions, that their bodies must always
have been perfectly clean. Human excrements were
not allowed to lie above ground. The offals and dung
of their sacrifices were carried to a distance, and they were
expressly told, that they must not allow of any uncleanness
in their camp, lest God should turn away from them
and abhor them. Add to all this the great heat and
dryness of the desert in which they wandered, which
would quickly parch up and carry off the moisture from
any dead carcases or putrefying matters that might be
allowed to remain notwithstanding the injunctions to the
contrary. Indeed if we consider the dryness of the climate
where these people were, and that they were constantly
attended by a large stream of water, it is difficult
to conceive any situation upon earth more healthy than
that of the Jews in the wilderness. If plagues therefore
came upon them, it is difficult to say how they could
have happened according to the ordinary course of nature;
and, if not according to this, it must have been by
an alteration of it, or by miracle.
The plague, as has already mentioned, in its very severe
state appears most commonly in the beginning of
an epidemic season, and is neither very common nor
very infectious. The most common mode in which it
invades the patient is with the symptoms of a malignant
fever; and of cases of this kind Dr. Russel has made
up his five classes of patients, the first or deadly kind
having been already described. In his second class, the
next in malignity to the fatal kind, the disease made its
attack with a slight shivering, succeeded by fever with
giddiness, vomiting, head-ach, and sometimes looseness.
In the night the fever increased, the thirst was excessive,
and the patient, harassed by the vomiting, &c. passed a
very unquiet night, frequently with delirium or coma.
Towards morning the fever abated, the sick recovered
their senses if delirium had taken place, but if coma, it
continued through the day, and the remissions were less.
Throughout the first day, and part of the second, the
pulse was full and strong, but on the second it began to
alter, and some of the characteristic signs of the disease
to appear. The principal of these was a certain muddiness
in the eyes, which sometimes took place even on the
first day. This is by our author accounted a symptom very
difficult to be described, and, though he recounts the descriptions
given by several authors, none are found adequate
to the real appearance. “It resembled (says he)
somewhat the dull, fixed eye observable in the last stage
of malignant fevers; but the dullness was different,
muddiness and lustre being strangely blended together.
It continued with little alteration in the remissions,
and even where the patient appeared sensible and
composed it did not increase in the febrile exacerbations,
but the eyes acquired a redness that added
wildness to the look, which abating or going off in
the remissions, the muddiness remained behind. It
was this which contributed chiefly in composing that
confusion of countenance which I shall not attempt
to describe, but which enabled me to pronounce with
tolerable certainty whether the disease was or was not
the plague, though not independently of other symptoms.
When this muddiness disappeared or abated,
it was constantly a favourable sign. After a critical
sign it often disappeared suddenly, but where there
was a succession of sweats, or where no visible crisis
happened, its disappearance was slow and gradual.”
Along with this muddiness the patient had a peculiar
confusion of countenance; the pulse quick and equal,
or low and fluttering, but rarely intermittent; the external
heat moderately feverish, at other times intense,
with irregular flushings, with pain at the heart, or oppressions
about the præcordia; burning pain at the pit
of the stomach, and incessant inquietude. When to
these symptoms were added a faltering in the tongue,
loss of speech, while the surface of the body became
cold and damp with clammy sweat, death was inevitable.
In the evening of the second day all the symptoms
became worse; and in the morning the patient
appeared to lie quiet more from his strength being exhausted
than from any change to the better. When
the vomiting had ceased, however, there was frequently
such a remission on the third day as gave the attendants
great hopes of a favourable event; but these hopes were
always fallacious and of short duration. Sometimes
where vomiting, looseness or hæmorrhage had preceded,
the patient died on the third day: at any rate, none of
this class recovered, whether the disease was left to itself,
or treated with medicine. The appearance of buboes
was of no consequence, for they never came to maturity,
and the little advances they made neither accelerated
nor retarded the termination of the disease, which
happened sometimes on the third, but more frequently
on the fifth or sixth day.
The third class of patients were equally unfortunate
with the other two. “The difference between the
second and third consisted in the absence of vomiting
at the beginning, the later accession of coma and other
bad symptoms, and a slight tendency to perspiration,
which very rarely occurred in the second. . . . From
the second or third night the course of symptoms in
both classes varied very little, and the termination of
the disease was in both the same: it may be added
they reigned together through all the periods of the
pestilential season, but were most prevalent in its augment;
for at its height, and in its decline, they gave
place to varieties of the disease less destructive.”
The fourth class was the most numerous of all. Its
distinctive marks were, “the continuance of the inflammatory
or febrile symptoms with less interruption than
in the other, a pulse more constantly sustained, or soon
recovering itself when hurried in the exacerbations;
the length and vigour of the exacerbations decreasing
in the advance of the disease; and, above all, the
prevalent tendency to a favourable discharge by the
skin, with the critical sweats on the 3d, 5th, or subsequent
days. . . . Vomiting was a concomitant in
about one fourth of the sick. The fever, for the
most part, was very moderate the first night, very
rarely accompanied with delirium, and almost never
with the comatous disposition. . . . The buboes and
carbuncles commonly made their appearance the first
day; but it was not unusual to see a successive eruption
of these in the course of the disease. . . . The
morning sweat, on the third day, in some cases proved
completely critical, but more commonly produced
only a remission so favourable as to encourage the expectation
of a more favourable crisis on the fifth; but,
where the patient neither sweat on the third, nor a
sensible remission took place on that day, some degree
of danger was always to be apprehended. . . . After
the sweat on the fifth, the subsequent exacerbations
proved slighter and slighter, and the buboes for the
most part advancing favourably, little or no fever was
left remaining after the beginning of the second week,
except perhaps symptomatic heats occasioned by the
eruptions.” In this class the patients sometimes appeared
only to have a slight attack, and yet at last
were seized with mortal symptoms, while others who
deemed to be much worse at first yet happily recovered
and did well, In general the severe pestilential symptoms
did not come on till a considerable time after the attack.
To the fifth class our author refers all cases of slight
infection, wherein the more formidable symptoms of
pestilence never concurred, and all the infected recovered.
“The access here was often attended with so little apparent
disorder, that the eruptions gave the first alarm;
and the fever which came on afterwards was frequently
so slight as not to confine the sick to the house. Others
found themselves indisposed for two or three days,
but were not sensible of any febrile heat whatever.
But in this class the disease did not always invade
thus insensibly. The febrile symptoms, especially the
first three days, sometimes run pretty high; and the
fever afterward, in nocturnal exacerbations particularly,
run out to the end of the week or longer: but, as
there was no concurrence of alarming symptoms, and
the exacerbations, terminating for the most part in
sweats, gradually diminished in force after the third or
fourth night, it was not difficult in the worst cases to
foretel the event at that period, nor necessary in others
to defer the decision so long.
“All the infected had buboes or carbuncles, and very
often both eruptions concurred in the same subject.
Persons not confined by indisposition were often, by
the inguinal buboes, prevented from walking abroad.
The carbuncles constantly formed the black crust,106 and
then suppurated; the buboes in one third of the sick
dispersed. The dispersion of the buboes was never
observed to be attended with bad consequences, notwithstanding
the general neglect of purging in the
decline of the disease: indeed very few had recourse
to remedies, topical applications excepted, unless perhaps
a bleeding at the beginning, where the febrile
symptoms ran high. This class was nearly as numerous
as the fourth, but began to predominate rather later,
and reigned most of all in the decline of the plague
in 1762.”
The sixth class must be omitted, as containing dubious,
anomalous and extraordinary cases. We shall
therefore proceed to consider the accounts of the plague
given by other physicians, which, without questioning
the accuracy of Dr. Patrick Russel in relating what he
has seen, may serve to throw some light on the subject,
by relating what others have seen. Dr. Alexander Russel,
in his Natural History of Aleppo, gives the following
description of it. “The distemper in itself is the
most lamentable to which mankind are liable. The
torments of heat, thirst and pain frequently unite in
some patients; an unspeakable dejection and languor
in others; and even those who escape with life do
not cease to suffer from painful and putrid ulcers, the
painful remains of the disease. The desertion of relations,
of friends, and of domestic servants, the want
often of the common necessaries of life, and the difficulty
of procuring medical assistance, are circumstances
likewise which aggravate the miseries of the sick, and
contribute greatly to augment the general horror.
“But, as no disease incident to mankind is in its nature
more terrible and destructive, so none is more difficult
to observe. Its symptoms are scarcely in all respects
alike in any two persons, and even vary extremely
in the course of an hour in the same subject. The
disease, attended in the beginning with symptoms not
highly alarming, often ends fatally in a few hours;
while the most formidable attacks, by a sudden and
unexpected alteration, sometimes terminate happily.
“The first complaints of those seized with this distemper,
were, in general, a coldness or shivering; sickness;
a vomiting of large quantities of porraceous bile, which
often had a very offensive smell; anxiety, or an inexpressible
uneasiness about the pit of the stomach; pain
in the back or loins; an intense head-ach; uncommon
giddiness, and a sudden loss of strength. Some
were sensible of a sharp shooting pain darting at intervals
into the parotid, axillary or inguinal glands. To
these symptoms succeeded a violent fever; in which,
while the sick complained of extreme inward heat,
their skin, externally to the touch felt little hotter
than usual. Sometimes this heat became general and
intense; at other times particular parts only were affected;
but it seldom continued long in the same degree,
having several unequal remissions and exacerbations
in a day. In these exacerbations the face became
florid, but would often from a deep scarlet change to
a livid colour, like that of a person almost strangled,
and, again suddenly changing, it would assume a cadaverous
paleness. The eyes, soon losing their natural
lustre, acquired a kind of muddiness; and the countenance
of most of the sick was ghastly and confused
beyond description. The pulse the beginning was
somewhat quicker and lower, but in other respects varied
little from the natural state. Within a few hours
it commonly increased in quickness and strength, but
seldom remained the some for an hour, nay scarcely
many minutes together; incessantly varying, both as
to strength and quickness, and without any manifest
correspondence with the other febrile symptoms.
“In such as complained of pains darting either into
the parotids, the arm-pits, or the groins, a small hard,
deep-seated tumour, with external discoloration of
the skin, was discovered by the touch in the part, and
these were the incipient pestilential buboes.
“The appearances now described were those of the
distemper on the first day, till evening, when the sick
always suffered a severe exacerbation, in which the
heat both internal and external became excessive;
and, as they generally were by that time delirious, it
was often with difficulty that they would be kept
within doors; they were greatly disposed to talk, but
faltered so in their speech, that what they said was
hardly intelligible, the tongue having shared with the
other organs in the general debility. The exacerbation
lasted the most part of the night; but the heat,
delirium, and inquietude abated towards morning, and
a manifest remission took place. Some recovered their
senses entirely, some partially, and then complained of
intense head-ach, or of pains from the buboes; it was
usual in this interval also that those who had carbuncles
began to complain of burning pain in those fiery
eruptions. The morning remission was commonly of
very short duration; the rigours, anxiety and delirium
soon returning more violent than before, attended with
a strong and frequent subsultus tendinum. These febrile
symptoms did not increase regularly as the day
advanced; but went away and returned at intervals
leaving short but alarming intermissions; for each
exacerbation surpassed that which preceded it either
in violence or duration. In the evening the pulse
could hardly be counted, by reason of its depression
and quickness; the patient became comatose, and the
respiration was quick, laborious, and interrupted.
The buboes which, some hours before, seemed manifestly
to advance, often subsided, and sometimes almost
entirely disappeared; the carbuncles, mortifying
at the top, resembled a great eschar made by a caustic:
and at this period also livid or black spots, of
various dimensions, often were found scattered universally
on the body.
“Under these circumstances, dreadful as they seemed,
some hope of recovery still remained; for, though
many of the sick died on the third day, several had a
favourable crisis on that day, by a profuse sweat; some
struggled to the fifth day, a few to the seventh, and,
here and there one, even to the eleventh; before
any critical alteration took place. Where a copious
sweat happened on the third day, if it did not prove
perfectly critical, it at least always considerably abated
the fever; which, in that case, was generally totally
removed by a second, though less profuse sweat,
on the fifth: and then besides weakness the chief remains
of the disease consisted in the pain of the eruptions.
“Nothing could be predicted with respect to the
event of the disease from the manner of its invasion;
those who had the most favourable escape having been
often in the beginning attacked with as alarming
symptoms as others were who died in a few hours.
Sometimes the febrile paroxysm, which had set in
with such formidable violence, dissolved in a few
hours, and left the patient languid indeed, and weak
in an extreme degree, but free from other complaints
except the pain arising from the bubo, which from
that period increasing in size, and advancing favourably
to maturation, was, in many cases, ready to open
in twelve or fifteen days: the patient all the while,
except the first day, walking about as usual. Great
numbers happily escaped, not only in the manner just
described, but likewise where the buboes never advanced;
for these tumours, so far from coming always
to maturation in such as recovered, very often discussed
without any bad consequence. Carbuncles
often began to digest before the termination of the fever
in a critical sweat.
“All the infected had buboes, except such as expired
suddenly, or survived the first attack a few hours only.
Instances of this dreadful kind were more particularly
observed in March 1743. The sick were seized in the
usual manner; but the head-ach, vomiting, and pain
about the præcordia, increasing every moment, proved
suddenly mortal, or terminated within a few hours in fatal
convulsions.” Dr. Patrick Russel observes, that such
instances of sudden death were very rare in the plague
of 1760, 1761 and 1762; and in these they happened
only in the winter, or early in the spring. In such sudden
deaths few had any appearance of buboes; but in
general the armpits and groins, or the inside of the arms
and thighs, became livid or black, and the rest of the
body was covered with confluent petechiæ, livid pustules
being here and there interspersed: but all these appearances
were more especially observed after death.
In the plague of 1760, vibices as well as livid and
black spots were frequently found on the corpse, but
not constantly. They were always suspicious in conjunction
with other circumstances, but their absence
was no proof, though frequently urged as such, that the
distemper was not the plague. The vibices sometimes
appeared several hours before death, but the livid spots
seldom or never.
The tongue in some was quite moist, and continued
to be like that of a healthy person throughout the disease;
in others, white at first, then yellow; at last
black, and covered with a dry, foul scurf or fur. The
thirst was generally very great, but never constant; returning
at regular intervals, and never appearing to correspond
with the danger of the fever. Sometimes it
was so little that the patient could not be prevailed
upon to drink a sufficient quantity. The appearance of
the urine was equally variable, and afforded no certain
prognostic; being seldom alike in any two patients in
the same stage of the distemper, and varying in the same
patient every day. The vomiting commonly ceased
after a few hours, excepting where the sick were induced
by thirst to load their stomach, in which case it
always returned. Sometimes the patients were costive,
in others a diarrhœa took place, but in most the discharges
were natural. No critical solution by urine or
stool seemed ever to take place. A few cases of hæmorrhages
from the nose and uterus were observed; and if
they happened after the second day, were soon followed
by a plentiful sweat, which commonly proved critical;
“a circumstance different from what has been usually
observed in the plague at other places.
“From the preceding account of the plague it will
readily be conceived that nothing can be more difficult
than to form any judgment or prognostic of the
event of the disease; in which, as it is justly remarked
by Morellus, our senses and our reason deceive us, the
aphorisms of Hippocrates are erroneous, and even
Hippocrates (as I am inclined to think) might have
erred in his judgment.”
Innumerable other histories of the distemper might be
given, but the following, it is hoped, will be sufficient,
along with what has been already detailed, to show that
the plague in former ages was the same as at this day.
In the terrible plague which broke out in the time of
Justinian, the distemper sometimes began with delirium,
and the patient instantly despaired of life; but
more generally people were surprised by the sudden
coming on of a slight fever; so slight that no danger
was apprehended either from the state of the pulse or colour
of the body. This, however, was quickly followed,
sometimes even on the same day, sometimes on the
second or third, by buboes or parotids (swellings behind
the ear) which when opened were found to contain a
black coal, or eschar, of the size of a lentil. If these
swellings suppurated kindly, the patient recovered, but
if not, a mortification ensued, and death was the consequence,
commonly on the fifth day. Black pustules or
carbuncles, covering the body, were signs of immediate
death, as was likewise a vomiting of blood in weak constitutions;
for this terminated in a mortification of the
bowels. Pregnant women generally perished, but women
were less susceptible of the infection than men;
and young persons were in more danger than old. Many,
who recovered, lost the use of their speech, and such
were not secure from a relapse.
In the last plague at Moscow, the symptoms were various,
according to the persons, constitution and the weather;
in general, head-ach, giddiness, shivering, loss of
strength, slight fever, sickness and vomiting, redness of
the eyes, white and foul tongue, with a dejected countenance,
buboes and carbuncles appearing on the second or
third day, but seldom on the fourth. The buboes were
seated chiefly in the glandular parts, the armpits and
groin, but sometimes made their appearance in the neck,
cheeks, &c. Sometimes these suppurated perfectly, and
then they proved beneficial, but not otherwise. Sometimes
they suddenly disappeared, after having attained
the size of walnuts; and this retrocession was always supposed
to be a sign of approaching death. Sometimes
they neither showed any sign of inflammation nor were
painful, and in such cases afforded no relief. Similar
swellings sometimes occured in the parotid glands, but
they were never equally beneficial with the buboes.
Carbuncles were gangrenous spots on the skin, resembling
a burn, with black, livid or red vesicles, bordered with
an inflammatory ring, and soon terminating in a hard,
black eschar. The anthrax is more prominent, penetrating
deeper into the adipose membrane, and attended with
more pain and inflammation. The disease was likewise
attended with petechiæ similar to those in putrid fevers,
but larger; also with vibices, which resembled the mark
of a whip, and were considered, as well as the petechiæ,
as mortal signs. No distinct account of the pulse could
be given; as, after the disease became general, physicians
did not choose to feel the pulses of their patients but
through a glove or tobacco-leaf. Worms called teretes
were frequently discharged both upwards and downwards.
Women with child generally suffered abortion, and were
carried off by an uterine hæmorrhage.107
According to Sydenham, the plague begins with
chilliness and shivering, like the fit of an intermittent,
succeeded in a little time by violent vomiting and oppression
at the breast, accompanied with its common
symptoms. These continue till the disease proves mortal,
or the kindly eruption of a bubo or parotis discharges
the morbific matter. Sometimes, though rarely, the
disease is not preceded by any fever; the purple spots,
which denote immediate death, coming out even while
persons are abroad about their business. But this hardly
ever happens but in the beginning of a very fatal plague,
and never while it is on the decline, or in those years
in which it is not epidemic. Sometimes swellings appear
without having been preceded either by a fever or
any other considerable symptom; but he conceives that
some slight and obscure shivering always precedes the
seizure.
Mariti, in his travels through Cyprus, &c. says that
the plague of 1760 began with loss of appetite, pain in
the shoulders, head-ach extremely violent, delirium,
vomiting, with a most excruciating pain in that part
where the tumour by which the plague is characterised,
is about to break forth. Death often took place on the
third day, and very few lived beyond the thirteenth.
The Abbe’s definition of what he calls the plague, and
which seems to be the pestilential bubo of the physicians,
is somewhat singular. “The plague (says he) is an oblong
tumour, shaped like a pumpkin, which is at first
of a flesh colour; but it gradually becomes red, and
at length blueish; and this is a sign that the disease
is incurable. If it continues red, and a little after inclines
to yellow, it is a sign that a suppuration will
take place: the swelling is then opened, and the patient
is sometimes cured.”
According to our author, the symptoms of the plague
do not appear till fifteen days after the infection is received;
and this is the reason of a law which subjects to
a proof of twenty days every person suspected of being
diseased. In this plague it was observed that people of
the soundest constitutions were the most subject to it,
and the least capable of resisting it. On the other hand,
it appeared to spare weak and delicate persons, whose
cure, in case of an attack, was much less difficult. A
greater number of Moors than of any other nation were
attacked by it; and when once they were seized, their
case was absolutely desperate. Those who had recovered
from the disease were less liable to a second attack, but
were not absolutely safe. “I have known some (says
our author) who have been ill seven times, and have
died of it at last.”
Dr. McBride informs us that in the plague which
raged at Marseilles and the adjacent places in 1720,
people on their first seizure seemed as if intoxicated with
drink; they lost the power of their limbs entirely, and
became so dejected that they gave themselves over to
despair from the very first attack. Along with the bilious
vomitings and purgings which generally took place
on the second day, quantities of small worms like ascarides
were thrown off. The more plentiful these evacuations
were, the more salutary; for those who vomited
and purged but little sunk down, oppressed with the
disease, and died before the fourth day, covered with
livid blotches and petechiæ; those who had the largest
evacuations had also the most plentiful eruptions of buboes
and parotid abscesses. When these appeared, the
patients rose, walked about, and became remarkably
hungry; the heat and thirst subsided, but the face continued
pale and languid, the pulse hard and frequent.
On the sixth, seventh, or eighth day, if the suppuration
stopped, and the humours went back, then came on oppression,
difficulty of breathing, furious delirium and
convulsions, which ended in death. When carbuncles,
or biles, with mortified sloughs, appeared in different
parts of the body, either alone or accompanied with the
glandular swellings, the patients scarcely ever escaped.
In great numbers of people tumours appeared without
any previous febrile symptom, and, in a few cases, went
off by resolution; in others they continued in a schirrous
state; but it was best when the tumours came to suppuration.
These are the most remarkable symptoms of this fatal
disease, which have been recorded by the physicians of
greatest eminence who have written upon the subject.
It remains still to give some particular description
of the buboes and carbuncles, which are supposed to
constitute in a particular manner the characteristic signs
of the distemper. Of these the following account, given
by Dr. Alexander Russel, seems to be sufficiently clear
and explicit.
Only a very few, and such as died suddenly, were
exempted from buboes, but only about one half had
carbuncles. In the latter plagues their proportion was
still smaller; but they seldom appeared earlier than in
the months of April or May. In 1742 and 1743, the
buboes often appeared on the first commencement of the
distemper, sometimes not till twelve hours after; in a
few instances not till two or three days; but in 1744
they were sometimes the first symptoms of the disease.
The buboes were generally solitary, the inguinal and
axillary more frequent than the parotid. “The inguinal
bubo for the most part was double; that is,
two distinct glands swelled in the same groin. The superior,
which in shape somewhat resembled a small
cucumber, lay obliquely near the large vessels of the
thigh, lower than the venereal buboes are usually found,
and it was that which commonly came to suppuration;
the inferior was round, and in size much smaller. I
once met with a case in which an axillary bubo divided
in like manner into two parts, one of which got under
the pectoral muscle, the other sunk deeper into the
armpit: both grew painful and inflamed, but that in
the armpit only suppurated.”
The bubo was at first a small hard tumour, painful
but not inflamed externally. These indurated glands
were deeply seated, sometimes moveable, at others more
or less fixed, but always painful to the touch. Sometimes
they would increase to a considerable size in a few
hours, with intense pain, then suddenly subside; and
these changes would take place several times in twenty-four
hours. “An exacerbation of the pestilential symptoms
immediately upon the decrease of the bubo, sometimes
prompted me to imagine it owing to the retrocession
of the tumour; but this did not happen so
constantly as to make me think it was so in reality.
The buboes, as far as I could learn, never advanced
regularly to maturation till such time as a critical
sweat had carried off the fever. In ten, twelve, or
fifteen days, from the first attack, they commonly
suppurated; having been all along attended with the
usual symptoms of inflammatory tumours. But I
have known them sometimes, nay, frequently, disappear
soon after the critical sweat, and discuss completely
without any detriment to the patient. At other
times, though grown to a pretty large size, the tumour,
about the height of the disease, would sink and mortify,
without any fatal consequences; for, as soon as
the crisis was complete, the mortification stopped, and
the gangrened parts separating gradually, left a deep
ulcer, which healed without difficulty. I met with
no instance of a bubo in which fever did not either
precede or follow the eruption.”
On the subject of carbuncles, Dr. Patrick Russel observes,
that “there are certainly varieties in them, but
perhaps these varieties have been unnecessarily multiplied,
from the same eruption having been viewed in
different stages of its progress; for all of them sooner
or later are covered with a black eschar.” Dr. Alexander
Russel describes them as follows: “The carbuncles
were commonly protruded the second day of the
disease; and though the muscular and tendinous parts
were more especially affected, no part whatever could
be said to be free of them. The carbuncle at first resembled
an angry confluent pock in its inflammatory
stage, but was attended with intense, burning pain,
and surrounded by a circle of a deep scarlet hue, which
soon became livid. By a progress very rapid, it then
spread circularly, from the size of a silver penny to an
inch and an half, two inches, nay, even three inches,
diameter; and the supervening gangrene often penetrated
deep into the substance of the parts affected.
In such of the sick as recovered, the gangrene usually
ceased spreading on the third day; and, a day or two
after, signs of suppuration were observed at the edge of
the black crust, the separation of which, advancing
gradually, was completed rather in less time than that
of the eschar in issues made by caustic. In cases where
the patient died, I was informed (for I saw none of
those cases myself) that a quantity of ichorous matter
oozed from beneath the eschar, which remained itself
shrivelled and hard, without any favourable signs of
separation or digestion.”108
Dr. Alexander Russel also describes another kind of
pustule, which he says appeared in a small number of
the sick, but which his brother Dr. Patrick had no opportunity
of observing in 1760. It had no livid or discoloured
circle surrounding it, but was filled with laudable
pus; and, when dry, the crust fell off, as in the distinct
small-pox. This was looked upon as a favourable
symptom, all who had it happening to recover.
We have now detailed, at considerable length, the
symptoms of the plague as mentioned by authors of great
eminence. To give a detail of all that has been said
upon this subject would be impossible; neither indeed
can it be thought necessary in the present treatise.
Whatever may have been omitted or too slightly mentioned
in this section, will naturally be considered when
we come to treat of the cure. It now therefore only remains
to say, whether the approach of a plague may be
known by any visible signs, so that people might in
some measure prepare themselves for the ensuing calamity.
Were we in possession of an accurate and authentic
history of the world, this question might be very easily
decided; but the uncertainty of ancient records, the
mutilated state of those which we do possess, the diversity
of opinions among mankind, and the unhappy disposition
to misrepresent, so common in all ages, render it very difficult
to say any thing upon the subject. If the theory
hinted at in this section (that plagues arise from some
commotion in the electric fluid) can be allowed to have
any foundation in nature, then it ought to follow, that
the forerunners of pestilence would be some electric
phenomena; and, from a perusal of the first and second
sections of this work, it will appear that such an opinion
is not altogether unfounded.109
The appearance of immense numbers of insects has
likewise been accounted a sign of approaching pestilence;
but if we suppose their appearance to be a sign, we can
scarce imagine their putrefaction to have been a cause, of
pestilence. In the east we are informed by Dr. Russel
that the inhabitants of Aleppo account the appearance of
insects, and even eclipses, as presages of the plague. They
suppose also that the stillness of frogs is a sign of pestilence;
but the same author informs us that all these
signs failed in 1760. Violent earthquakes and famines
seem to be more certain signs, though even these are
not always to be depended upon; it being evident
from historical accounts that pestilence has sometimes
preceded, and sometimes followed, earthquake and famine.
Mr. Gibbon, however, ascribes to the above-mentioned
causes, viz. insects, earthquakes, and even
comets, the dreadful plague which took place in the
reign of Justinian. At least, all these preceded it; but
perhaps the insects were only meant to be accounted the
cause of the plague. The cause of the insects must remain
in obscurity. According to him, “In a damp but
stagnating air, this African fever is generated from
the putrefaction of animal substances, and especially
from the swarms of locusts, not less destructive to
mankind in their death than in their lives.”
This dreadful plague was preceded by comets and
most violent earthquakes. A remarkable comet appeared
in 536, supposed to be the great one observed by Sir
Isaac Newton in 1680. This, we are told by astronomers,
revolves round the sun in a period of 575 years;
but the failure of astronomical predictions in the return
of the expected comets of 1759 and 1789, shew the
futility of such calculations. Another comet appeared
in 539, and these comets were attended with an
extraordinary paleness of the sun. Mr. Gibbon observes,
that earthquakes, which he calls a fever of the earth,
“raged with uncommon violence during the reign of
Justinian. Each year is marked by the repetition of
earthquakes of such character, that Constantinople has
been shaken above forty days; of such extent, that
the shock has been communicated to the whole surface
of the globe, or at least of the Roman empire.
An impulsive or vibrating motion was felt; enormous
chasms were opened, huge and heavy bodies were discharged
into the air, the sea alternately advanced and
retreated beyond its ordinary bounds, and a mountain
was torn from Liburnia, and thrown into the waves,
where it protected as a mole the new harbour of Botrys
in Phenicia.”
According to Dr. Sydenham the plague at London in
1665 was preceded by a very cold winter; the first continued
till spring and went off suddenly towards the end
of March. Peripneumonies, pleurisies, quinsies, and
other inflammatory disorders, then made their appearance,
along with an epidemic fever of a particular kind,
which did not yield to the remedies successful in other
epidemics. About the middle of the year the plague
began, and increased in violence till the autumnal equinox,
when it began to abate, and by the ensuing spring
was entirely gone. Our author says that the plague seldom
rages violently in England but once in thirty or
forty years; but since his time, which is upwards of a
century, no plague hath appeared. He supposes the
plague and other epidemics to depend on some secret
constitution of the air, but pretends not to say what that
constitution is. But, besides this constitution, he is of
opinion that there must be another circumstance, viz.
the receiving the effluvia or seminium from an infected
person. Thus he supposes that a single infected person
is sufficient to poison a whole country; the general mass
of atmosphere being infected by the breath of the diseased
and the effluvia of the dead bodies. “Thus (says he)
the way of propagating this dreadful disease by infection
is rendered entirely unnecessary; for though a
person be most cautiously removed from the infected,
yet the air received in by breathing will of itself be
sufficient to infect him, provided his juices be disposed
to receive the infection. I much doubt, if the disposition
of the air, though it be pestilential, is of itself
able to produce the plague; but the plague being always
in some place or other, it is conveyed by pestilential
particles, or the coming of an infected person from
some place where it rages, to an uninfected one, and
is not epidemic there, unless the constitution of the air
favours it. Otherwise I cannot conceive how it should
happen, that, when the plague rages violently in one
town in the same climate, a neighbouring one should
totally escape it, by strictly forbidding all intercourse
with the infected places; an instance of which we had
some few years ago when the plague raged with extreme
violence in most parts of Italy; and yet the
Grand Duke, by his vigilance and prudence, entirely
prevented its entering the borders of Tuscany.” As
to the nature of the disease, when once produced, Dr.
Sydenham is of opinion that it is altogether inflammatory;
for which he gives the following reasons: 1. The
colour of blood taken away that resembles that in pleuritic
and rheumatic disorders. 2. The carbuncles resemble
the mark of an actual cautery. 3. The buboes
are equally disposed to inflammation with any other tumours
that come to suppuration. 4. The season of the
year may be adduced in proof of this; for between spring
and summer, inflammatory disorders, as pleurisies, quinsies,
&c. are common.
Before we put an end to this section, it may now be
proper to say a few words by way of apology for the
many apparent digressions from the subject which have
appeared in it. In the first place, then, the work being
intended for general inspection, and not merely for medical
readers, it became absolutely necessary to introduce
a number of things which for medical readers
would have been totally superfluous. It was to be supposed
that the book might come into the hands of some
who had not read any thing concerning the structure of
the body, who had not heard of any of the systems of
medicine now prevalent, or the different doctrines they
contain. It was impossible to write in an intelligible
manner for such people without giving some few hints
concerning all these subjects: the same consideration
made it necessary to enter pretty largely into the discoveries
concerning the composition of the atmosphere
and various kinds of elastic fluids, concerning heat, &c.
In doing this the writer was under a necessity either to
adopt some of the doctrines he took notice of, or to
animadvert upon them. If he has ventured freely to
give his sentiments, it is not with a view to establish a
theory of his own, but to direct the attention of the
reader to those natural agents which seem to be at
present too much overlooked, principally because they
are less accessible to our senses, and of consequence less
subject to experiment, than others. If therefore in this
treatise it is suggested that the atmosphere acts on the
human body by its internal or latent heat, and by its
electricity, as well as by its other properties; if the
writer is inclined to believe that these are in fact the
most powerful parts of it; that we never can act without
them, and that in short our life and health are in
immediate dependence upon them; I say, that none of
all these things are in opposition to any fact hitherto
discovered, either of the medical kind or any other.
On the other hand, in all ages physicians have sought
for some constitution in the air, inexplicable, and perpetually
unknown, to which diseases might be ascribed
that could not be supposed to originate from any of its
ordinary properties. To explore this constitution is as
great a desideratum at the present moment as two thousand
years ago; and any attempt to investigate it, or a
conjecture relating to it, cannot be supposed inconsistent
with any thing already discovered and ascertained.
There are many things which lead us to think that
electricity is very much concerned in diseases, and
among the rest we must account the new discovery
of Dr. Perkins’s metallic conductors a very notable
proof of it. These, when first ushered into the world,
were made by many a subject of ridicule; but the evidence
in favour of their efficacy, both in America and
in various parts of Europe, seems now to be decisive in
their favour; and, if they act at all, it is almost impossible
to suggest any other principle than that of electricity
to which their efficacy can be owing. No doubt
it is difficult to draw the line properly betwixt credulity
and skepticism, but where credible testimony determines
any thing to have actually happened, or where solid reasoning
gives room to suppose any thing to be probable,
it never can be invalidated by any argument a priori
formed against the possibility of such a thing taking place.
In page 128 it is said, that M. Lavoisier, by introducing
the new chemical nomenclature, “has entailed the
greatest curse upon the science it ever met with.” All
apology for this bold assertion is absolutely necessary,
and the quotation made from Dr. Ferriar may be deemed
inadequate, or perhaps misapplied. In passing this
censure on the nomenclature I wrote from experience.
The new nomenclature, instead of promoting my improvement
in chemistry, hath had a direct contrary tendency.
An instance of the inconvenience and ambiguity arising
from it is given p. 135, when speaking of Dr. Girtanner’s
theory. But a much more remarkable example is
to be met with in the review of Dr. Monro’s Chemical
Treatise, where we find him censured for the very
same ambiguity taken notice of with regard to Dr. Girtanner.
“He might have observed (say the reviewers)
the distinction between the hydrogen and inflammable
air, and between the oxygen and pure air, as well
as between the azote and impure air: he has mentioned
these as synonimous, whereas they are terms
that express bases, or substances in a concrete state
(what I have called the condensable part) and the compounds
of these substances and heat, when they assume
the form of gases or elastic fluids.” (Monthly
Rev. for 1790, p. 26.)
That the terms invented by Lavoisier and others have
not been received with perfect unanimity by the chemists
of the present day, is evident from Dr. Pearson’s
“Translation of the New Chemical Nomenclature,”
which is not only a translation, but a vindication of it. In
the course of his work he quotes the translator of the
Chemical Dictionary saying, that, “from the zeal of
reforming language, such a number of reformers may
arise, that our ears will not be less stunned, nor our
understandings less perplexed, than if we were exposed
to the clamour of Babel, or the thaw of words of
Sir John Mandeville.” To this Dr. Pearson replies,
that there is no reason to fear any such bad consequences.
“The distinguished superiority of a system produced by
a De Guyton, a Lavoisier, or a Bergman, would surely
supercede the work of persons of inferior ability.” It
is impossible to know the persons here designated, unless
the Doctor points them out. If he chooses to call himself
one of them, we can have no objection. He certainly
has dissented, in one article, from “the system
produced by De Guyton, Lavoisier and Bergman,” and
this is with regard to the word azote. This is the term
announced to us as the most proper for denoting a certain
kind of air. But Dr. Pearson determines nitrogen to be
more proper. Even this has not given entire satisfaction,
for Dr. Mitchell has adopted the word septon in
preference to both azote and nitrogen. Thus, instead of
the original phrase phlogisticated air, used by Dr. Priestley,
we have four; for as long as the works of Dr. Priestley
remain, the original term will be used by some, while
with others it will be so much disused that perhaps they
will not understand it when it happens to occur. Nor
are corrections of this kind all that we have to fear. Professor
Wiegleb, who has written a System of Chemistry
in quarto, has therein changed almost all the nomenclature
invented by Lavoisier. Instead of it he gives a nomenclature
of his own, in which he makes very much
use of the termination cratia, from a Greek word signifying
strength; thus, instead of saying the acid of fluor,
we are to say fluoricratia. I must confess that to me
the perpetual repetition of this termination has a very
ridiculous appearance; but the misfortune is, that in
the case of nomenclatures we have no choice. We cannot
choose one and reject another: good or bad, we
must take both; and were an hundred new ones to arise,
we must be condemned to learn them all. Nor is even
this the worst. Wiegleb’s scholars, for instance, accustomed
to the language of their teacher, will be apt to
put it into their writings, perhaps without proper explanation;
and thus such writings must be unintelligible
both to old and new chemists: and thus it will be with
as many others as choose to invent new chemical terms.
Were this a proper place for entering into a discussion
of Lavoisier’s nomenclature, it might easily be shown
that the terms are not more proper than those which
preceded them; but no real inconvenience can arise from
the propriety or impropriety of a mere name. It is the
resemblance of the terms to one another, and the facility
with which mistakes may be made, that gives just ground
of complaint. Nor is it any just reason to accuse a person
of want of judgment or carelessness because he hath
mistaken these terms. We see that even Dr. Monro has
not attended to every circumstance; and if a man of
his experience and accuracy hath been inaccurate in this
respect, what is to be expected from others? How
easily may the words sulfate, sulfite, sulphuret and sulphure,
be mistaken for one another, either in writing or conversation!
Yet a mistake of this kind would totally
pervert the meaning of the person who used it. The
scripture finds fault with those who make people offenders
for a word; but here we are in danger of being
made offenders for a letter. In short, taking into account
the inconveniences arising from this nomenclature
itself, the numberless corrections and amendments
(no matter whether real or imaginary) to which it may
be subjected, and the number of others totally different
from it which may arise, I cannot help looking upon
the introduction of it into chemistry as an evil of the
first magnitude; an evil which cannot be remedied by
any art, but must continually become worse and worse.
Of the best Methods of Preventing the Plague.
THESE methods may be classed in the following
manner: 1. Those most proper for avoiding
the infection, supposing the disease to be infectious.
2. The proper mode of resisting or removing those local
causes which may give rise to it, or may co-operate with
the infectious matter in giving greater force to the disease,
should it happen to be introduced; and, 3. The
best method of preparing the body for resisting pestilential
attacks, should we happen to be so situated that no
external method of defence could be used.
With regard to the first of these intentions the flying
from places infected has been so universally recommended,
and so generally received, that the precept has been
made up into the following proverbial Latin distich:
“Hæc tria tabificam tollunt adverbia pestem
Mox, longe, tarde, cede, recede, redi.”
These words prevent the plague’s infectious pain,
Go quick, fly far, and slow return again.
This maxim hath been put in execution in all ages,
but often with so little regard to humanity that it cannot
by any means be recommended without very considerable
limitation. The reparation of the sick from all
promiscous intercourse with the sound, in times of pestilence,
seems to be dictated by common sense; but this
may be done without killing them, or leaving them to
expire in the miserable state to which they are reduced by
the disease. Mr. Howard informs us that in some places
ships which have the plague on board are chased away and
burnt; and instances of cruelty with regard to infested
individuals have been formerly mentioned. Dr. Mertens
is of opinion that cutting off all the communication
between the infected and healthy is the only means
of preventing the disease from spreading. The good of
this practice was observed in one of the hospitals at Moscow.
All the avenues to it were shut up, but one which
was strictly guarded, and every suspected article prohibited
from entering. Infected clothes and utensils were
burned, and the houses where the sick had lived were
purified by the fumes of vinegar and gun-powder.
In this mode of prevention it is of the utmost consequence
to ascertain the distance to which the contagion
extends; in the next place to know whether by means
of clothes, cotton or other kinds of merchandise it may
be imported from one place to another; and in the third
place how long the infection may remain in these kinds
of goods; so that people may know when the danger is
over. As to the distance, it seems to be generally agreed,
that it is but small. Some of the answers to Mr. Howard
by the physicians of whom he inquired, have been
already related. Of the infection of the plague he speaks
in the following manner:
“In my opinion this distemper is not generally to be
taken by the touch, any more than the gaol-fever or
small-pox; but either by inoculation, or by taking
in with the breath the putrid effluvia which hover
round the infected body; and which, when admitted,
set the whole mass of blood into fermentation, and
sometimes so suddenly and violently as to destroy its
whole texture, and to produce putrefaction and death
in 48 hours. Those effluvia are capable of being
carried from one place to another, upon any substance
where what is called scent can lodge; as upon wool,
cotton, &c. and in the same manner that the smell of
tobaco is carried from one place to another.
“The infection in the air does not extend far from
the infected object, but lurks chiefly (like that near
carrion) to the leeward of it. I am so assured of this,
that I have not scrupled going, in the open air, to
windward of a person ill of the plague to feel his pulse.
The rich are less liable to the plague than the poor,
both because they are more careful to avoid infection,
and have more large and airy apartments, and because
they are more cleanly, and live on better food, and
plenty of vegetables; and this I suppose is the reason
why Protestants are less liable to this distemper than
Catholics during their times of fasting, and likewise
why the generality of Europeans are less liable to it
than the Greeks, and particularly Jews.
“It is remarkable that, when the corpse is cold of a person
dead of the plague, it does not infect the air by
any noxious exhalations. This is so much believed
in Turky, that the people there are not afraid to handle
such corpses. The governor of the French hospital
at Smyrna told me, that, in the last dreadful
plague there, his house was rendered almost intolerable
by an offensive scent; especially if he opened any of
those windows which looked towards the great burying-ground,
where numbers every day were left unburied;
but that it had no effect on the health of himself or
family.”
It is likewise a matter of the utmost importance to
ascertain the time at which the disease is introduced into
any town or district. Dr. Canestrinus, in a treatise on
this distemper, published at Saltzburg, complains greatly
of the dissensions among physicians concerning the nature
of the distemper, owing to which its existence is
frequently denied, and thus its ravages are propagated
immensely beyond the limits which might otherwise
circumscribe them. Of this he gives the following remarkable
instance: “In the year 1770 a disease with
uncommon symptoms prevailed at Bodrogh in Upper
Hungary, which carried off a number of persons
in a short time. A physician of the county of Zemplin
was sent to inquire into the nature of the malady.
He reported that the disease was of a suspicious nature,
having a great resemblance to the plague. His
report was received by the nobility and health-officers
with indignation, as if untrue. Another was sent,
who, without hesitation, pronounced the disease an
epidemic scurvy. In the mean time the disease, being
left to itself, spread wider, and raged with such
violence as to carry off seventeen persons in one house.
The nature of the disease now becoming apparent,
proper measures were taken, and the infected separated
from the sound, by which means the disease was
confined within a small district.110” With regard to
the infection of the disease, or contagion, as it is commonly
called, he expresses himself as follows: “The air
is not capable of diffusing the contagion to any considerable
distance from the infected subject unimpaired
in its power, but, like other poisonous matter, it is
capable of dilution in the atmosphere, so as to be
rendered at length innoxious. The contagion of the
plague will be entirely prevented from spreading if all
access to, and all intercourse with, the sick be strictly
prohibited: whence the following forms a safe and
infallible prophylactic of the disease:
“Mox, longe, tarde, cede, recede, redi.
Go quick, fly far, and slow return again.”
“No change in the habit takes place previous to the
action of the contagion, but the body is from the first
equally susceptible of it as of the itch, or any other
infectious disease. Whilst the plague ceases in the
civilized parts of Europe spontaneously, or by human
precautions, its revival is prevented, from the care that
is bestowed in purifying or destroying every infected
substance. In the east, on the contrary, this precaution
is totally neglected; whence it is probable that
the disease is not reproduced anew, but that it is perpetuated
by the former fomes, as happens with us in
the small-pox. The matter producing the ordinary
epidemics is widely diffused in the atmosphere, and
capable of infecting through a widely extended space.
The pestilential poison, on the contrary, is confined to
the vicinity of the affected body, and becomes so dilute
at the distance of a few paces only as to be incapable of
further action. Hence it appears that the plague is
much easier avoided than epidemic disorders. The
more abundant the contagious matter is, the further
probably is the power of its infection carried. This
is the reason that the mere separation of the sick and
suspected from the healthy is so much more efficacious
in destroying it at its commencement than at a later
period. To restrain epidemics within bounds is impossible;
but with the contagion of the plague, it is certain
that it can be confined by art to a narrow spot.”
Of the truth of this last assertion our author gives a
remarkable, instance in his own practice about the time
that the plague stopped at Bodrogh. Having been
sent into Cassovia, along with two other physicians, they
were informed by the surgeon of the lazaretto, that an
unusual disease had broken out in the district of Zboina,
which had suddenly proved fatal to many. On inquiry
it was found that it had come from Bodrogh in the
following manner: Two young men, returning from
the vintage at Tokay, slept a night in an infected house,
and stole some clothes belonging to those who had died
of the plague. He who carried the clothes died by the
way: his father carried home the bundle, kept them
unpacked for some weeks, but having at last worn them,
he and all his family fell victims to the same disease.
The pestilence began to spread, and shewed an appearance
of great malignity. Our author did not hesitate
to declare its true nature, and in consequence of his
declaration all communication was cut off between the
adjacent countries and the infected spot, by a cordon of
the military. The infected were separated from such as
were only suspected, and these last from the sound:
three infected houses were destroyed by fire, and other
means (to be afterwards related) were used with a view
to destroy the contagion itself. Thus the disease was
prevented from spreading; and none but such as had
been previously suspected were seized.
To the same purpose the Abbe Poiret thinks it an
easy matter to extinguish the plague entirely. He was
a witness to the ravages of the disease in Barbary, and
thinks it the most easily avoided of any distemper; but
the misfortune is, that there are many things in their own
nature very easily accomplished, which the inattention
or perverseness of mankind render utterly impracticable.
Such, it is to be feared, is the extinction of the plague
by the means just mentioned; for though these means
might be enforced in a country district or small town,
yet, where the pestilence enters a large and populous city,
there are so many modes of concealing its existence, and
the unknown intercourse of the sick with the sound
must be so frequent, that it seems scarce possible to prevent
the malady from spreading.
In London, whether it arose from a neglect of using
the precautions for too long a time, or from any other
cause, cannot well be known; but the attempts of the
magistrates to separate the sick from the sound certainly
were not attended with any good consequence.
“The consternation (says Dr. Hodges) of those who
were thus separated from all society, unless of the infected,
was inexpressible, and the dismal apprehensions
it laid them under made them but an easier prey to the
devouring enemy. And this seclusion was on this
account much the more intolerable, because, if a fresh
person was seized in the same house but a day before
another had finished the quarantine, it was to be performed
over again; which occasioned such tedious
confinements of sick and well together, as sometimes
caused the loss of the whole. Moreover, this shutting
up of infected houses made the neighbours fly
from theirs, who might otherwise have been a help to
them on many accounts; and I verily believe that
many who were lost might have been alive, had not
the tragical mark upon their doors driven proper assistance
from them. And this is confirmed by the examples
of other pestilential contagions, which have been
observed not to cease until the doors of the sick were set
open, and they had the privilege of going abroad.”
The Doctor sets forth also the arguments on the other
side; but whatever might have been the advantages of
a separation of the sick from the healthy, if conducted
in a manner less capable of hurting the feelings of humanity,
it is evident that in the London plague the
methods attempted to prevent the disease at least did
no good.
In countries where the plague generally prevails, and
the Europeans are united in the opinion that it is necessary
to separate themselves from the natives, the method
of shutting up is attended with the most salutary effects,
as has been attested by almost every traveller who has resided
there for any time. Accidents among them are
very rare, though not altogether without example. At
Alexandria in Egypt, M. Volney tells us, that as soon
as the plague makes its appearance the European merchants
shut themselves up in their khans and have no
communication with the rest of the city. Their provisions
are deposited at the gate of the khan, and received
there by the porter, who takes them up with iron tongs,
and plunges them into a barrel of water provided for the
purpose. If it is necessary to speak to any one, they
keep at such a distance as to prevent touching with their
clothes, or breathing on one another; by which means
they preserve themselves from this dreadful calamity, unless
by some accidental neglect of these precautions.
Some years ago a cat, which passed by one of the terraces
into the houses of the French merchants at Cairo, conveyed
the plague to two of them, one of whom died. This
state of imprisonment continues for three or four months,
during which time they have no other amusement than
walking in the evening on the terraces, or playing at
cards.
The doctrine of predestination, and still more the barbarism
of the government, have hitherto prevented the
Turks from attempting to guard against this destructive
disease: the success, however, of the precautions taken
by the French, has of late begun to make some impression
upon many of them. The Christians of the country
who traffic with the French merchants, would shut
themselves up like them; but this cannot be done
without permission from the Porte. A lazaretto was
some years ago established at Tunis; but the Turkish
police is every where so wretched, that little can be hoped
for from those establishments, notwithstanding their extreme
importance to commerce and the safety to the
Mediterranean states. The very last year afforded a
proof of this; for as violent a plague as ever was known
broke out there. It was brought by vessels coming
from Constantinople, the masters of which corrupted
the guards, and came into port without performing quarantine.
Water carriers have never been attacked by it.
Mariti says, that in the island of Cyprus, and on the
continent of Syria, every European, on the slighted appearance
of the plague, after taking the necessary precautions,
shuts himself up with his family. The Mahometans
alone, more intrepid, go abroad as usual, converse
with each other, give such assistance to each other as may
be necessary, and often fly to the relief of a Christian
when deserted by his friends. This arises from their belief
in predestination. The Mahometans of Syria, however,
less familiarized with this scourge, make use of
some precautions, which were augmented in 1760.
They published an ordonnance forbidding every vessel
attacked by the plague to enter their ports: but their
vigilance in this respect was so remiss, that it was not sufficient
to prevent the contagion. The governor of Acre
checked the progress of this plague, by giving the inhabitants
the means of retiring from its ravages; and these
means, though absolutely contrary to the dogmas of the
Mahometan religion, were eagerly embraced. The Europeans
became their models; and the governor, after
deriving from them every necessary information, shut
himself up, after their example, together with his numerous
family. The mufti alone, being the protector of
the Mahometan law, cannot imitate a conduct which
that law condemns. Instead of shutting himself up in
a prudent confinement, he thundered forth against this
new method, reproached the governor for his conduct,
and, having treated him as an impious person, threatened
him with all the vengeance of Heaven. The governor,
however, only laughed at this pious folly of the mufti,
and sent a detachment of soldiers to impose on him a
fine of two hundred and fifty sequins, for having dared
to ascribe to him, in matters of religion, an ignorance,
from every suspicion of which his age ought to have secured
him.
In the time of plague, the proper precautions are, to
shut one’s self closely up, and to receive no provisions or
other things, except those on which the plague has no
influence. The people of Syria, however, in 1760, admitted
every kind of provisions without fear, but not
without using certain precautions. They did not receive
warm bread; flesh of every kind was thoroughly washed,
and milk was strained through a linen cloth, in order to
free it from the smallest particle of animal hair. All
kinds of pulse were soaked in water, and they abstained
from peaches, apricots, and other fruits which are covered
with a downy rind. Fowls were cooked out of the house,
for fear that some small feather might adhere to them.
Flowers were altogether proscribed. Letters were opened
by the person who brought them; and they were never
read until they had been steeped long enough in vinegar
to be purified without effacing the writing. Every
thing was received into the house by means of a rope of
herbage suspended from a window. The governor employed
every precaution which he thought likely to guard
him from the contagion; and, by shutting himself closely
up, he set an example which the rest of the Mahometans
did not neglect to follow. Besides this he caused the
streets to be cleansed; and carried his vigilance so far as
to forbid the caravans which arrived from Damascus,
where the plague swept off four or five thousand
people every day, to enter the city. He obliged them to
submit to a proof of eight days without the walls, and
established regulations of the same kind respecting vessels
coming from Alexandria or Damietta. One precaution
taken in the time of plague is, to prevent cats from entering
houses: an open war is therefore declared against
these animals; and, wherever they are found, they are
knocked on the head with large clubs. This is a cruelty
absolutely necessary; for there is no vehicle that will
convey the infection with more certainty or rapidity than
the hair of cats. Rats and mice multiply in consequence
of their destruction; but there is no instance of
their ever having propagated the plague. This disease,
when it attacks men, spares quadrupeds and birds. The
furs of the one, and the feathers of the other, however, attract
and communicate the infection. People ought
particularly to keep from goats and sheep; from horses
and oxen little is to be apprehended.
All these precautions were sometimes ineffectual.
The French at Acre, who there, as well as throughout
Syria, are collected into one quarter, used every precaution
that could be thought of, yet, on the 30th of March,
1760, five of them were infected. They belonged to
the hospital of the Holy Land, and the monks were instantly
ordered to shut themselves up. They did so;
and eight of them died, one only escaping.
Mr. Howard likewise gives particular accounts of the
precautions used in several different countries through
which he travelled. In Malta two kinds of quarantine
are performed; one for ships with clean bills, the other
for those with foul. The former lasts 18 days.111 The
crews and passengers are allowed to buy provisions, and
converse by means of enclosures with stone posts and
palisadoes. A letter received from a Turkish ship was
taken by a pair of iron tongs, dipped in vinegar, put into
a case, and laid for about a quarter of an hour on a wire
grate under which straw and perfumes had been burnt;
after which the letter was taken out and opened by one
of the directors. In this island ships with foul bills must
perform quarantine eighty days; but, at the end of
forty, may change their station. The different kinds of
goods are separated and placed in proper order under
cover. The cottons are taken out of the bags containing
them, and placed on rows of piles on boards, laid on
stone pillars about 18 inches from the floors; and, in
repacking them they are flung over a man who gets into
the bags, and treads down the cotton; the consequence
must be the exposing him to great danger, should
any infection remain.
Mr. Howard took a voyage to Venice in a ship with
a foul bill, on purpose to know every thing relative to
the performance of quarantine. “A messenger (says
he) came in a gondola to conduct me to the new
lazaretto. I was placed, with my baggage, in a boat
fastened by a cord ten feet long to another boat in
which were six rowers. When I came near the landing
place the cord was loosed, and my boat was pushed
with a pole on the shore, where I was met by the
person appointed to be my guard. Soon after unloading
the boat, the sub-prior came and showed me
my lodging; a very dirty room, full of vermin, and
without table, chair or bed. That day and the next
morning I employed a person to wash my room; but
this did not remove the offensiveness of it, or prevent
that constant head-ach which I had been used to feel
in visiting other lazarettos and some of the hospitals
in Turky. My guard sent a report of my health to
the office, and, on the representation of our consul, I
was removed to the old lazaretto. Having brought
a letter to the prior from the Venetian ambassador at
Constantinople, I hoped now to have had a comfortable
lodging. But I was not so happy. The
apartment, consisting of an upper and lower room, was
no less disagreeable and offensive than the former. I
preferred lying in the lower room, on a brick floor,
where I was almost surrounded by water. After six
days, however, the prior removed me to an apartment
in some respects better, and consisting of four rooms.
Here I had a pleasant view; but the rooms were
without furniture, very dirty, and no less offensive than
the sick wards of the worst hospital. The walls of my
chamber, not having been cleaned perhaps for half a
century, were saturated with infection. I got them
washed repeatedly with boiling water, to remove the
offensive smell, but without any effect. My appetite
failed, and I concluded I was in danger of the slow
hospital fever. I proposed whitewashing my room with
lime slaked in boiling water, but was opposed by
strong prejudices. I got this, however, done one
morning through the assistance of the British consul,
who supplied me with a quarter of a bushel of fresh
lime for that purpose. The consequence was, that
my room was immediately rendered so sweet and fresh,
that I was able to drink tea in it in the afternoon, and
to lie in it the following night. On the next day the
walls were dry, as well as sweet, and in a few days I
recovered my appetite. This room was lime-whited in
November, and in a very rainy season. In the following
March, in complaining to the under sheriffs in
Newgate of their inattention to the clause which orders
this in the act of parliament for securing the
health of prisoners, their excuse was, that they were
afraid of dampness.”
An health-office was established at Venice in 1448,
in the midst of a very destructive pestilence. The old
and new lazarettos are both built on little islands, surrounded
not only by canals, but high walls. They
have only a ground floor, and one over it, and are divided
and subdivided into a great number of apartments,
each having an open court in front, with plats of
grass, which is not suffered to grow too high; nor are
any trees suffered to grow within this district, or a good
way from it. The internal government is managed by
a prior, who must not be related to the magistracy nor
any of its ministers. He must have no interest nor concern
in shipping nor in trade. He must see all the
gates and doors of the apartments locked every evening
by sunset; he takes the keys into his possession, and
suffers them not to be opened before sunrise; and, in
case of any suspicion of infection, the gates must be kept
constantly locked, and opened only for necessary occurrences
in presence of the prior. He must not suffer
dogs, cats, &c. to lodge in the lazaretto. He must
neither buy nor sell, nor suffer others to do so, within the
lazaretto. No fishing boats or other small craft to come
within a certain distance, or keep communication with
those performing quarantine. Provisions are received
by poles seven or eight feet long, and the money dipped
in vinegar and salt water before it is received. The prior
and his substitute must carefully avoid touching either
goods or passengers in quarantine, and for this purpose
they keep a cane to make those who approach them
keep their proper distance; but if by an unfortunate accident
they should be contaminated, they must perform
quarantine. Any person maliciously touching them is
liable to punishment.
Ships are strictly forbid to use any ropes but such as
are tarred. Wool, silk, cotton-wool, woollen and linen
clothes, and furs especially, are accounted the most dangerous
goods. Animals with long hair are subject to full
quarantine; but short haired ones purged by swimming
ashore; feathered animals, by sprinkling with vinegar
till wet.
The celebrated Dr. Mead, though an enemy to the
cruel mode of abandoning the sick, or treating them
with any kind of harshness, was perfectly sensible of the
necessity of using every precaution for preventing pestilential
contagion from being imported. In his opinion
it is not sufficient that ships should perform quarantine,
“the only use of this being to observe whether any die
among them. For infection may be preserved so long
in clothes among which it is once lodged, that as
much, nay, more of it, if sickness continues in the ship,
may be brought on shore than at the beginning of the
forty days, unless a new quarantine be begun every
time any person dies; which might not end but with
the destruction of the whole ship’s crew.” He is therefore
of opinion that lazarettos ought to be established on
small islands near the sea-coast; and in this Mr. Howard
agrees with him. The latter recommends the lazaretto
at Leghorn as the best in Europe. Dr. Mead also
very much insists on the utility of destroying the clothes
of the sick, because, says he, they harbour the very essence
of the contagion. He quotes in favour of this opinion
what Boccacio says he saw at Florence in 1348;
viz. that two hogs, finding in the streets the rags which
had been thrown out from off a poor man dead of the
disease, after snuffling upon them, and tearing them with
their teeth, fell into convulsions, and died in two hours.
This is one of the things which Dr. Moseley looks upon
to be incredible. It is indeed very marvellous, and
seems to be contradicted by M. Deidier’s account of the
dog at Marseilles who swallowed with impunity the filthy
pus and pestilential matter adhering to the dressings of
plague sores: but, when a person of credit informs us
that he saw any thing, we scarce know how to contradict
him. The evidence of pestilential contagion adhering
to clothes, does not depend on such accounts. That
lately quoted from Dr. Canestrinus is decisive on the subject;
and he informs us that one of the methods used
by himself to stop the plague in Zboina, above mentioned,
was, the burning of the clothes of infected persons. He
says that the pestilential contagion resembles that of the
small-pox, in being of a fixed nature; and that all who
studiously avoided communication with the sick, or with
whatever fomes might carry the contagion, escaped it altogether.
“That the contagion of the plague (says he)
may lie dormant for a considerable time, and be carried
to a great distance by the medium of packages, &c.
and again revive with its former violence, is proved by
various circumstances. Chenot relates, in his treatise
on the plague which raged in Transylvania, that the
infection was revived a whole year after it had disappeared;
and other similar instances are adduced.” If
this revival happened from infected clothes or soft goods,
it shows them to be dangerous in the extreme; but of
this we have not any direct proof, neither indeed is such a
belief quite consistent with what takes place in all plagues,
viz. that the clothes of the infected are worn by the sound,
without producing any reinfection. In the great plague
at London, for instance, where an hundred thousand probably
perished, and a much greater number must have
been infected, we cannot suppose that all the clothes belonging
to such an immense multitude were burned, or
never made use of again. It is of necessity therefore
that we suppose the pestilential contagion to become
effete, and to lose its virulence, after some time; and
this seems to be very much hastened by exposure to the
atmosphere. The doing of this, however, by obliging
people to put their naked arms into bales of suspected
goods, has such an appearance of cruelty, that Dr. Mead
has proposed to judge of the presence or absence of infection
by allowing little birds to fly about among them;
“because (says he) it has been observed, in times of
the plague, that the country has been forsaken by
the birds; and those kept in houses have many of
them died.” But, though he says this upon very
great authority, no less than that of Diemerbroeck, yet
we can by no means look upon the fact to be absolutely
determined. Dr. Russel indeed says that the desertion
of the birds is looked upon by the Turks to be the sign
of an approaching plague; but this failed in 1760.
Thucydides says that birds of prey deserted the territory
of Athens during the great plague in his time; and he
supposes them to have been poisoned by feeding upon
the bodies of such as died of the disease. It is possible
that such food might be disagreeable to them, but no
proof is brought of any of them having been actually
poisoned by it. As for birds kept in houses, it is possible
that in a time of general calamity they might have been
neglected, and died for want of proper food, &c. Dr.
Mead also quotes an instance which cannot be credited in
a consistency with undoubted testimonies that pestilential
contagion does not extend but for a very little way.
Upon opening an infected bale of wool in the field near
Cairo, “two Turks employed in the work were immediately
killed, and some birds which happened to fly
over the place dropped down dead.” Such accounts
have arisen from a supposition that the whole mass of
atmosphere was violently infected; but this would be totally
inconsistent with the life of any human creature,
and we may well put down this, as that of pestilential infection
arising from cities like a cloud, as merely chimerical.112
It is too well known that pestilential contagion,
instead of soaring in the air, keeps very near the ground.
We now come to the second mode of prevention, viz.
removing these local causes which, in the opinion of
some, may produce a plague in any country, and, in that
of others, may increase or set in action the contagion
previously existing. These causes have been enumerated
by the late Dr. Smith,113 in a Dissertation on the pestilential
Diseases which at different times appeared in the
Athenian, Carthaginian and Roman armies, in the neighbourhood
of Syracuse. They are, 1. The climate and
season. 2. The situation of the armies; and, 3. Their
condition. The climate of the island of Sicily in general
he observes is extremely pleasant at some seasons of
the year; in the neighbourhood of Syracuse particularly
storms are so infrequent during the former part of the
year, that the sun is never obscured for a whole day.
Even in the month of January, however, the weather is
warm, and as the season advances the heat becomes insupportable.
In autumn it is rendered somewhat unpleasant
and unhealthy by the frequent rains and chillness of
the evenings. But, in particular places, during the hottest
season, nothing can exceed its unhealthiness. According
to Barichten, “the least stagnant water is sufficient,
in the heats of summer, to poison the atmosphere:
its effects on the countenances of the poor
people who live in its vicinity are evident; and a
stranger who travels through the island in this season
ought to avoid ever passing a night near them.” De
Non says, that “as soon as the sun enters the Lion, this
country becomes the house of death: fevers of the
most malignant kind seize on the imprudent or unfortunate
wretch that spends a night near them (ponds
and marshes) and few escape with life when attacked
by so virulent a disorder.”
To the poisonous effluvia of these marshes the Doctor
attributes, in an especial manner, the plagues which took
place in the armies. In the second year of the Peloponnesian
war, the Athenian army was encamped, as we
are told by Thucydides, “upon marshy and unwholesome
ground;” and that such kind of encampments will
produce diseases in an army is well known. In the time
of Dionysius, when the Carthaginian army under Imilco
suffered so dreadfully, or rather was totally destroyed,
his camp was situated on an eminence between two
morasses, the heat at that time being excessive. Hannibal,
the predecessor of Imilco, had also lost great part
of his army by a plague, though he had been encamped
in a healthy situation; but, in order to raise a wall
which should overlook the city, he had taken the materials
of the tombs found in the common burial place,
the city at that time containing two hundred thousand
inhabitants. “From the uncovering and disturbing of
so many dead bodies (says our author) arose a terrible
pestilence, which carried off immense numbers of the
Carthaginians, and amongst the rest the general himself.”
To the unhealthy situation of the armies also
the Doctor ascribes the plague which took place in the
Roman and Carthaginian camps in the time of the second
punic war; and the Carthaginians suffered most, by
reason of their being nearer to the marshes. The state
of mind, the cleanliness of the person, &c. also must be
taken into account; and our author shows that neither
of these could be supposed favourable to the Carthaginians.
That personal cleanliness, and breathing pure air,
should contribute to the health of individuals, or to any
number of them collected into camps or cities, seems to
be agreeable to reason and common sense; nevertheless
we find that this has been denied, and even Dr. Canestrinus
says that “in the plague of Lyons and Marseilles
it was observed, that the most populous parts of these
cities, where the streets were narrow and filthy, suffered
less from the disease than those which were more airy
and clean. At the time of the plague in London in
the time of Charles II, the physicians advised that all
the privies should be opened and exposed; the fetid
odour from which having pervaded the city, the plague
was stopped! Is it from this cause (the author asks)
that the plague has seldomer visited Spain, the towns
of which are intolerably offensive from their want of
cleanliness?”114
This certainly seems a very strange doctrine, nevertheless
the fact that Spain is but little subject to the
plague seems undeniable, and as it is no less certain that
the towns are excessively filthy, it would seem that
cleanliness is not effectual in preventing it. But, however
agreeable the smell of human excrements may be to
the Spaniards, or to the English physicians in former
times, it seems to be less so at present. “I am persuaded
(says Dr. Ferriar) that mischief frequently arises from
a practice common in narrow back streets of leaving
the vaults of privies open. I have often observed
that fevers prevail most in houses exposed to the effluvia
of dunghills in such situations.” In Spain the
opinion seems to have been but lately eradicated; for
some years ago, an order having been issued by government
that the streets of Madrid should be kept somewhat
cleaner, the people were so much exasperated at being
threatened with the loss of the savoury odour, that a rebellion
had almost ensued, and the physicians declared the
smell of human excrements to be the most wholesome
thing in the world.115
That the confinement of human effluvia, along with
heat and want of water, will produce a malignant fever,
is certain from the example of the unfortunate people
confined in the Black Hole at Calcutta. In this case
the distemper seems to justify the opinion that plague
may be artificially produced, perhaps more than any
other upon record; for Dr. Ferriar informs us that it
was attended with eruptions resembling those of the true
plague. In this case, however, the confinement was
beyond example in any situation which can be supposed
incident to a city or camp. There is no country in the
world where the inhabitants are equally numerous with
those of the empire of China, its population at present
being estimated by Sir George Staunton at three hundred
and thirty-three millions, a number equal to one third of
the supposed inhabitants of the whole globe; of consequence
the cities must be immensely crowded with inhabitants;
yet it remains free from plagues. Human
effluvia therefore, in the most populous state in which
mankind can exist in society, are not able to taint the
atmosphere of a country or city. The following is Dr.
Clark’s account of that celebrated empire: “The
whole empire of China is represented to be extremely
delightful; the soil rich, the air pure, and the industry
of the inhabitants astonishing. As it produces
every luxury and necessary of life, it is justly esteemed
one of the most fertile countries in the world. As the
Chinese prohibit emigration, and seldom or never engage
in war, their country is extremely populous.
Every river maintains a proportion of inhabitants adequate
to the land, whose families live continually in
boats, without having any other place of residence.
Their number of people lays them under the necessity
of carrying industry to the greatest height; for
otherwise their country, fertile as it naturally is, would
be insufficient to maintain the inhabitants. Every
inch of land is cultivated; no forests nor woods, nor
even a single tree, is suffered to obstruct the labours
of the husbandman. Canals are cut every where to
water the fields, and marshes are manured for the
cultivation of rice. By these means health and plenty
are, in a great measure, the portion of its inhabitants
through all the seasons of the year. The only terrible
and fatal diseases to which they seem to be subject
are the small-pox and leprosy.”
But, though our author determines in general that
the air of China is pure, this cannot apply to every part
of it without exception. On the contrary he describes
in the following manner Wampoa, a village about fourteen
or sixteen miles below the city of Canton, on Canton
river: “It is the usual station of all European
ships in this river. On one side the land is low,
marshy, and covered with water, forming swamps fit
only for the cultivation of rice. The extent of these
swamps is considerable; the tide rises high, and overflows
great part of them; but the intersection of the
rivers renders them more pure than they would otherwise
be; and consequently the air is much healthier
than one could expect from the unfavourable aspect.”
In like manner Canton city he says “is built on a
very extensive plain, and is large and populous. Here
the government allow the English, Dutch, French,
Danes and Swedes separate factories on the banks
of the river. The city, though paved, is very wet in
rainy weather; and the water makes its way under
the factories of the different nations every tide. The
houses are built with bricks; the apartments are in
general small, and not very lofty, and the ground
stories are very damp. When the business of the season
is over, the supercargoes remove to Macao, a
Portuguese island, subject to the Chinese government.
The city of Macao is situated on a rising ground;
the whole island is dry, rocky and barren; it is, however,
plentifully supplied with provisions by the Chinese;
and, though the air is very sultry, yet it is tolerably
healthy.”
From the preceding account it is plain, that the
causes which operate in the production of plagues and
epidemic diseases in other countries, though they exist
in China, do not act there with equal efficacy. At
Wampoa the marshes in the neighbourhood must, in the
hot season, emit noxious effluvia as well as any where
else, and there can be no certainty that the overflowing
of the tide is sufficient to put a stop to their malignant
influence. At Canton the water penetrates below the
floors of the houses, and we have seen from Dr Fordyce117
that in other countries the sprinkling of a floor with clean
water, and the encampment of an army upon ground
where water was found at a small depth below the surface,
were sufficient to produce fevers; yet here it is not
so. In this city also the inhabitants are numerous, and
the apartments small; so that neither the perspiration of
multitudes, nor the moist exhalations from water stagnating
in the streets, nay, under the houses themselves,
are able to produce the diseases in question. Again, at
Macao the sultry heat of the air has as little effect as the
rest.
Lastly, in Pekin, the capital, the population and the
crowd are immense. According to Sir George Staunton,118
the city is about one third larger than London; but, as
he supposes119 it to contain three millions of inhabitants,
the population must be twice and a third-part as great as
that of London in proportion to its bulk. “The low
houses of Pekin (says he) seem scarcely sufficient for so
vast a population; but very little room is occupied by
a Chinese family, at least by the middling and lower
classes of life. In their houses there are no superfluous
apartments. A Chinese dwelling is generally surrounded
by a wall six or seven feet high. Within
this enclosure, a whole family of three generations,
with all their respective wives and children, will frequently
be found. One small room is made to serve
for the individuals of each branch of the family, sleeping
in different beds, divided only by mats hanging
from the ceiling. One common room is used for
eating.”
Where diseases are prevalent, circumstances of the
kind just mentioned would certainly be urged as evident
causes of them; but in China we see that something disarms
such causes of their power. People, however, seldom
want a salvo for any thing. “The crowds of
people, at Pekin (says our author) do not prevent it
from being healthy. The Chinese indeed live much
in the open air, increasing or diminishing the quantity
of their apparel according to the weather. The
atmosphere is dry, and does not engender putrid diseases;
and excesses productive of them are seldom
committed.” But, if the dry air at Pekin contributes
to the health of the people, why does not the moist air
of Canton produce diseases? Besides, in this empire
there are multitudes of people who live entirely upon
the water, in a kind of houses constructed upon junks,
employed in carrying grain from place to place, or for
other purposes.120 Sir George Staunton computes the
number of inhabitants on a branch of a single river
to be no less than an hundred thousand. What then
must they be throughout the whole empire! Yet these
people, though continually exposed to moisture, as well
as to an almost inconceivably crowded situation, are yet
no more subject to epidemics than others. Our author
does not specify the excesses which produce disorders.
Intemperance in drinking no doubt is one of them; but
Dr. Patrick Russel expressly says, that he never saw an
instance of the plague being brought on by intemperance.
Lastly, with regard to living in the open air, Mr.
McLean has ascribed to the vicissitudes of this element
the principal if not the only cause of epidemics.
“A fact worthy of notice (says he) is, that aged persons
and children are both seldomer and less severely attacked
by epidemics and pestilential disorders than
the young and middle aged, and women seldomer and
less severely than men. Now, if contagion was the
source of these diseases, the case would be exactly reversed.
Old people, women and children, being more
in the way of contagion, would be more frequently
and more severely attacked. But the young and middle
aged, being more exposed to the vicissitudes of the
atmosphere, the principal source of those diseases, they
are consequently more severely attacked. It has been
a puzzling question to solve why old people and children
are less exposed to plague, &c. but the solution
will be no longer difficult if it should be proved that
these diseases are always produced by certain states or
vicissitudes of the atmosphere, together with the application
of other powers co-operating in the production
of indirect debility.” In the country we speak of,
however, this solution fails in a manner almost as evident
as can be imagined. “The removal of the embassy,
(says Sir George Staunton) was a disappointment to
several persons belonging to it, who had made arrangements
for passing the winter at Pekin. Judging of its
temperature by the latitude of the place, a few minutes
under 40° north, they were not aware of the violent
effect of the great range of high Tartarian mountains,
covered perpetually with snow, upon that capital,
where the average degree of the thermometer is under
twenty in the night during the winter months, and
even in the day time is considerably below the freezing
point. The usual inhabitants were guarded against
cold, not only by habit, but by an increase of clothing
in proportion to its intenseness, consisting of furs, woollen
clothes and quilted cottons. They are not accustomed
to the presence of fire. They have no chimneys,
except to kitchens in great hotels. Fires, on
which Englishmen chiefly depend against suffering by
the sharpness of the atmosphere, could not well answer
that purpose in houses which are so constructed as to
admit the external air almost on every side. Stoves
are, however, common in large buildings. These
stoves are situated frequently under the platforms on
which the inhabitants sit in the day time, and rest at
night. The worst weather experienced in that capital
might be considered as mild by the Tartars, coming
from a climate still more rude; but other foreigners
are said to feel themselves less comfortable at Pekin
in the winter than in the summer, though the heat is
then raised to the opposite extreme. In both they
seem to require a seasoning. Several individuals of the
embassy fell ill during their stay; and all did not recover.
The human frame seems calculated for the hottest
rather than the coldest atmosphere, and to exist at
the equator rather than the pole.”
Here we are involved in difficulties much greater than
before. It appears that even the fine climate of China
is healthful only to its own inhabitants. They can bear
the vicissitudes of the air, which Europeans cannot. The
prevention of plagues or mortal diseases then must consist
in some mode of living by which people can accommodate
themselves to the country which they inhabit,
and without which every other precaution will be ineffectual.
The diseases with which the attendants of the
ambassador were seized could not be owing to any slovenliness
or dirtiness in their lodgings or food, or to
want of apparel; nor were they more exposed to the
inclemencies of the air than others; only they were in a
strange country, where that inexplicable constitution of
the elements acted upon them in a manner different
from what it did on the natives, and, while it was
friendly to the latter, proved pernicious to the former.
But there was a time when even China was as unhealthy
as other countries; for the great plague in 1346 began
in the northern part of it. We have seen, in a former
section, that this was preceded by the most dreadful and
violent wars throughout the whole Asiatic continent.
Since the cessation of these violent wars the Chinese have
staid at home, and applied themselves to the arts of peace,
particularly to agriculture, which they have carried, we
may say, to its utmost perfection. This seems therefore
to be the true method of removing all those local causes
which produce epidemics, or at least of preventing them
from doing hurt; and, without attention to the natural
duties and occupations of man, it is to be feared that all
artificial modes of prevention will be found not only precarious
but ineffectual.
Dr. Smith in the dissertation above mentioned observes,
that “it may be doubted whether any moral
cause would be sufficient to protect, for a long period,
an unaccustomed resident in a marshy situation from
the usual consequences.” This is no doubt very probable
but, from the example of Lord Macartney’s attendants
in China, it appears equally probable that it
makes little difference whether the country be marshy
or not. Dr. Lind has many excellent observations upon
the subject of unhealthy countries, and gives particular
directions for strangers how to act, when obliged to
expose themselves to the inclemencies of the weather;
but none of these being effectual in preventing the access
of the true pestilence, we must still adhere to the
old Latin adage already quoted, p. 302. Flight seems
to be the most effectual method. To avoid migrations
to those countries where it usually rages, and, if it
were possible to persuade the inhabitants of such countries,
to imitate the example of Chinese industry, instead
of allowing the greater part of the territories they
possess to lie waste, would in all probability gradually
lessen both the frequency and violence of this terrible
disease. Migrations of large bodies of people,
especially for the purposes of war, are greatly to be
dreaded. If a few Englishmen, possessed of every thing
necessary, could not keep their health at Pekin, what
must have been the probable consequence of landing an
army of an hundred thousand, with a view to conquest?
Or what could we expect if the Chinese were to “pour
forth by millions” into other countries in order to conquer
them? Dr. Lind takes notice that even of the first
Portuguese adventurers to Africa, such as escaped the
first sickness continued afterwards to enjoy good health.
He likewise observes that many who left Britain, after being
seasoned to the countries to which they went, chose
rather to remain abroad for life, than to run a new risk
by going back to their own country. It is not therefore
so much the greater unhealthiness of the country to
which we go, as the change, which is to be dreaded. If
therefore great bodies of men will employ themselves in
constant rambling from one country to another, no
wonder that diseases break out among them, unknown,
either in the countries they have left, or those to which
they go.
We come now to the third mode of prevention, viz.
that of destroying the infection after it has begun to
exist. This is varied according to the nature of those
things which we suppose to be infected. The general
notion of infection taking place in the atmosphere has
been already spoken of; but the uncertainty of this
hypothesis, and the apparent impossibility of altering a
constitution of the atmosphere, must certainly leave
very little room for hope in this case. It hath, however,
been attempted by various methods. Hippocrates
adopted the opinion that all diseases were produced by
the air, and from him it was borrowed by Lucretius, as
we are informed by the annotator on Creech’s Translation
of that author. “In his book de Flatibus (of
winds) says the annotator, after a long narration of
the effects that the air produces, he at length falls on
the subject of diseases, all of which he affirms to be
bred and generated in the bodies of animals by means
of the air. First (says he) I will begin with the most
common fevorous disease, which accompanies, in a
manner, all diseases whatever. For there are two sorts
of fevers, one that is promiscuous, and common to
all, and is called the plague; the other, by reason of
unhealthful diet, is peculiar only to such as use that
diet; but of both these kinds of fevers the air is the
sole author and cause, for the common fever or plague
happens alike to all, because they all breathe the same
air; and it is certain that the like air, being alike mingled
in like bodies, must beget like fevers.” In consequence
of his theory, this great physician advised to have
recourse to fire as a purifier of air in times of pestilence.
But experience doth not warrant the success of this method;
neither indeed can we suppose that it could be successful,
unless people were able to kindle such fires as
would absorb the whole atmosphere of a country. This
method was tried in London without the least success;
nay, seemingly with bad effect; for, the very night the
fires were lighted, more than four thousand people died;
and, a few days after, an end was put to the experiment
by such violent rains as extinguished all the fires at once.
The burning of infected clothes has already been
taken notice of; but though this must certainly prevent
any new infection from arising from these clothes, it will
not prove that the infection may not evaporate during
the time of burning, and, being volatilized even beyond
its natural pitch, by the heat, may do mischief at
a greater distance than could have happened had they
been let alone. The instance, formerly quoted from
Dr. Huxham, of the small-pox being disseminated by
the smoke of burning infected clothes, if not a proof, affords
at least a strong presumption, of the danger of such
a practice. The only way of perfectly ensuring safety
in such a case would be to burn them by the sea-side,
when the wind blows from the shore. Were the smoke
allowed to pass over land, and great piles burnt at once,
it is impossible to say how far the contagion might be
carried.121
Another mode of purification is by exposing suspected
goods to heat, to the vapour of vinegar, &c. fumigating
with gun-powder, sulphur, &c. and on this principle
various powders of fumigation have been invented;
some of which are said to have been very successful in
Russia; and the composition of one is given by Dr.
Alexander Russel in his Natural History of Aleppo;
but all these are undervalued by Dr. Guthrie,122 who calls
the practice of fumigation or smoaking, an “inadequate
and ineffectual ceremony.” Dr. Mitchel, also discommends
them, saying that they are advised “without any
proof that these destroy pestilential matter, and while,
at the same time, it is certain that they diminish more
or less the wholesomeness of the atmosphere with
which they are mingled.”123 Of late the vapours of
pure nitrous acid (the nitric, according to the new nomenclature)
has been recommended, with the boldest
appeal to experience; but the consideration of this naturally
belongs to the second part of this work, where we
shall have occasion also to consider the theory of the
septic acid. In the mean time we must go on with some
farther account of the different modes of fumigation.
“There is no better corrective (says Allen from Diemerbroeck124)
of a pestilential air, than fire; as much
experience has taught us. Hippocrates subdued and
extinguished that famous plague, which came amongst
the Grecians from Ethiopia; for he commanded great
fires to be kindled throughout the whole city, especially
in the night time, to purge away the pollutions
of the air. It is believed that a fire made with juniper-wood
or ash, tends much to correct the venomous
corruptions of the air. The kindling of sulphur and
gun-powder purify the air, and drive away its corruptions;
so does the burning of amber, pitch, frankincense,
&c. so do the fumes of vinegar raised with red-hot
irons, or bricks.” According to Etmuller, “Hippocrates
drove away that famous plague in Greece by
the use of sulphur; the fumes of it are very much
commended to correct the air, and make drink more
wholesome; it prevents all manner of corruptions and
alterations, as well as the putridinous alteration of the
blood. In a great degree of malignity, the shirt and
clothes may be impregnated with the fume of
sulphur.”
Here we have accounts of a disease, called that famous
plague, driven away by two different methods; and, to
complete our dilemma, Dr. Canestrinus tells us that the
plague at Athens is said to have been staid “by sprinkling
the streets with wine.” What an expensive remedy,
when the odour of privies was afterwards found to answer
as well! “Whilst the plague was raging at Oczakow,
an earthquake125 happened on the very day that it
began to decline. In this case did any vapour issue
from the earth destructive of the pestilential contagion?
or did former noxious exhalations cease in
consequence of the convulsion of the earth?126 Sorbait
relates, that, in the time of the vintage in the
neighbourhood of Moselle, the plague ceased like a
miracle, while the must was in a fermenting state.
At Vienna likewise it was observed that, during and
at the close of the vintage, the disease manifestly declined;
which may have been owing to the great
quantity of fixed air in the atmosphere.”
To this our author adds, that “places adjoining to
spice-shops have generally remained free from infection;
and, in the plague of London, all those employed
in shipbuilding escaped the disease. Smiths
also and cooks remained uninfected.” M. Volney
tells us that, in Egypt, water-carriers are exempted;
and Baldwin, that oilmen are in the same happy predicament;
while on the other hand Allen quotes Boerhaave
saying, that “Forestus, Diemerbroeck, the French,
English, and Germans, observed, that all dealers in
soap, washers, and all who by their business used soap,
nay, who only wore shirts washed with soap, presently
died of the plague.”
From so many and so discordant opinions, the only
conclusion we can draw is, that, when once a pestilence
has invaded a country, there is not any possibility of
operating upon the contagion in such a manner as to
destroy it. If the plague ceases, it must do so naturally,
and we cannot accelerate this cessation. This is entirely
conformable to the opinion of Dr. Patrick Russel.
Speaking of the decline of the plague at Marseilles, and
the vigorous exertions of the magistrates to put a stop
to it, he says, “The causes now enumerated might no
doubt have some effect, but a more powerful and
general cause had begun long before to restrain the
havock of the pestilence, which had declined visibly
in the month of September, and in those of October,
November and December declined with a rapidity
not ascribable to the exertions of the most vigorous
police. This cause is generally supposed to be some
change in the constitution of the air; but which has
hitherto been defined with no better success than that
peculiar state of the atmosphere which, in conjunction
with contagion, is absolutely necessary to render the
plague epidemical.”
Dr. Russel takes notice of the methods of extinguishing
contagion already mentioned, by kindling fires, &c.
and disapproves of them. We shall not therefore spend
more time in considering whether or not there is any
probability of eradicating or mitigating the violence of
a plague when once it is introduced. However this
may be impracticable in so large a space, it seems that it
certainly may be done in smaller spaces, ships for instance;
or, if not with the true plague, at least with malignant
and infectious fevers. Dr. Trotter, in his Medicina
Nautica, has laid down methods for accomplishing
this, and expresses the highest confidence in their
success. He adopts the doctrine of contagion, of which
he gives the same definition that in this treatise is given
of infection, viz. “Something propagated from diseased
bodies, or from substances that have been in contact
with them, producing a similar disease in other persons127—the
propagation of contagion, as well as its
reception into the healthy body. A more aggravated
degree of malignity will generate a greater quantity of
infection, and, as it may be confined in a larger or
smaller space, it will be less or more noxious. A fever
may be called malignant, when, with the symptoms
of debility, there is a cadaverous smell arising from the
body, an unusual fœtor of the breath, stools, and other
excretions, the tongue black and parched, the eye
dusky or yellow, the countenance bloated and dejected,
and the skin sallow. In approaching a sick bed of this
kind, a person not much accustomed to such visits
will be very liable to receive the infection; and the
unpleasant smell will be much sooner perceived than
by the physician or other attendants. We conclude
that a malignant typhus is more apt to generate contagion,
because slight cases are found not to extend
to others, even though no mode of precaution has been
used. The disease itself is incapable of generating infection,
till after a certain period; but this period is
uncertain: it seems to depend on the nature of the
symptoms, whether they are mild or malignant. We
are assured of this fact, from a timely separation having
prevented the farther progress; and by this means ALONE,
I apprehend, we eradicate contagion in SHIPS, or ANY
WHERE ELSE. In the small-pox128 the disease seems
incapable of infecting another person before the second
or third day of the eruption. With the measles it is
otherwise. The disease may be propagated at the
most early stage of the eruption; and, if I was to be allowed
to conjecture on the subject, I would say, that
the contagion is the offspring of the catarrh (the cough
and hoarseness resembling a cold) which accompanies
the measles.
“Substances imbued with the exhalations from infected
bodies, if not exposed to the air, have their powers
of communicating the disease increased; or, in
other words, the infection from fomites (infected cotton,
clothes, &c.) is said to become more virulent than it
was when first separated from the body.
“I am of opinion, with others, that the exhalations or
excretions of the sick are the vehicles of contagion. It
is these which impregnate the atmosphere with noxious
matter: they affect in like manner bed-clothes, or
apparel, and every thing that can imbibe them, when
in contact with the diseased body. When bed-clothes,
or body-linen, but particularly silk or woolen cloth,
have been exposed to these exhalations, and then heaped
together for a length of time, the noxious effluvia
are, as it were, multiplied, and will more certainly
infect others than they did at first. The bales of goods
which brought the plague to Marseilles, and affected
the people that opened them so suddenly, had their
virulence increased by not being duly ventilated.
When the jail-fever was brought into court by the
prisoners at Oxford assizes, and more lately at the
Old Bailey, the fever was propagated from the clothing
of the prisoners; no doubt, from being confined in
impure, ill-aired cells, this infection became more virulent.
The highly concentrated state of contagion,
in the bales of goods, could only have been brought
to that degree of virulence from the closeness of the
package: it cannot be supposed that human beings
could have put them together otherwise. The nurses
of hospitals know well, as Dr. Lind tells us, that there
is most danger of catching a fever when they pile
heaps of bed-clothes or body-linen together for a
few days, before it is carried to the wash-house. The
washer-women at Haslar have also told me the same
thing. They know when a dangerous fever is in the
hospital by the bad smell of the clothes: this makes
them air them abroad, till the smell is gone, and then
they can wash them with safety. But, if it happened,
from the hurry, that this could not be done, or if it
was neglected by design, many of them were seized
with the sickness. The porters and people employed
in cleaning and fumigating the blankets and beds at
Haslar are well acquainted with this fact, and they
measure the danger by the badness of the smell. This
ought to instruct every body to stand to windward of
these infected substances when they are opened; as
the current of air would then carry it the other way.
In one of the courts of justice, the people who stood
between the prisoners and a window, into which the
wind blew, escaped the infection, while those on the
other side were sufferers.
“In the summer of 1793, while the Orestes brig, commanded
by Lord Augustus Fitzroy, lay at Plymouth,
she was anchored very near and to leeward of an
army transport, which had on board a very malignant
fever among the soldiers. While the soldiers were
moved on deck, to go on shore to the hospital, the
crew of the Orestes, from curiosity, walked on deck to
look at them. Such was the concentrated state of
the contagion among the clothing and bedding of
these troops, on bringing them from below, that
eighteen people belonging to the brig were quickly
seized with the same fever, the infection of which
had been conveyed by the current of wind. It did
not, however, extend much farther in the Orestes,
from the attention of her commander. But this
ought to be a caution for ships to keep clear of those
that have fevers on board, as a virulent CONTAGION
may be conveyed to a considerable distance.
“Dr. Lind is inclined to think that washing the
bed-linen in hot water, even when first shifted, is attended
with much risk; and that the noxious matter
may be volatilized by the heat of the water, and affect
the woman. For this purpose he has recourse to his
favourite process, of fumigation, to insure the washer-woman.
The heat of his fumigating furnace would
no doubt dry the linen, and exhale any moisture; but
our practice in the Charon (the hospital ship) was, to
plunge everything as it came from the bed into a tub of
hot water kept ready on purpose. The linen was washed
and dried immediately after. We had in that hospital
many malignant cases of typhus, and some deaths,
yet no infection was ever spread there.”
Our author next proceeds to inquire into the cause of
this excessive concentration of the infectious matter in
fomites, or clothes, bed-clothes, bale-goods, &c. The
most plausible reason, he says, that could for some time
be assigned for this, “was, the generation of animalcula;
the cotton or woollen clothing was said to serve as a
nest for the corpuscles to multiply; and thus the contagion
was thought to increase seven fold.” This
theory had an effect on the practice of physicians, both as
to the prevention and cure of fevers supposed to proceed
from thence. Our author looks upon the hypothesis to
be chimerical, because none of these animalcules have
ever been made visible by the best microscopes. But
there is no necessity for supposing the animalcules to be
invisible to the naked eye. They may creep on the
ground, or fly in the air, without being observed by us.
Mr. Baker’s discovery of the insect which not only poisoned
eleven hundred thousand times its bulk of water,
but infected a much greater bulk of air, with its effluvia,129
shows that such a thing may be possible; and in dubious
matters bare possibility ought always to produce inquiry.
If the perspiration of human bodies when confined
becomes noxious, why may not that of a multitude
of insects be so too? There is no necessity for
supposing that an insect must be swallowed, or inhaled
by the breath, before it can do hurt. What Dr. Trotter
says of the variolous contagion emitted from the
human body will apply equally to insects. “What has
been called the insensible perspiration (says he) which
arises from the surface and the lungs, we have a right
to believe carries with it in solution a portion of the
variolous matter which charges the atmosphere with
the contagion of small-pox, even in such quantities as
to impregnate the clothing of attendants and visitors;
by which means it has been frequently carried to families
and villages many miles distant from its source.”
The smallness of size of insects can be little objection
here. A skunk is but a small animal, yet it spreads its
odour farther than an hundred diseased human bodies
could propagate the plague.130
On this subject, however, we may remark, that though
the nurses and attendants on hospitals measure the degree
of infection by the smell, yet people are by no means
safe in approaching patients about whom no smell can
be perceived. We have already seen, from Dr. Fordyce,
that what may be called the pure infection of fevers
is not perceptible by any of our senses; and there
are examples of very offensive smells issuing from diseased
bodies without any contagion ensuing. Dr. Trotter
tells us, that “a patient in typhus was sent from the
Venerable to the hospital ship, with a fœtor about
him, that exceeded any thing of the kind that ever
came within the Doctor’s knowledge. After being
washed and shifted, it still continued, and was perceived
at a considerable distance. He died in a few
days, yet nobody was infected from him, either in his
own ship, or in our hospital. There was probably
some peculiarity of constitution here.” In M. Deidier’s
experiments, above related, the dog which eat
the dressings of the plague sores, after being infected with
the disease, emitted a very disagreeable odour, but we
do not find that the odour was in any way infectious.
In the Encycloped. Britan, art. Med. Hydrophobia, we
find an account of an hydrophobic patient (and a patient
who recovered) in whom the blood drawn from a
vein was as black as ink, and stunk abominably, yet this
stench was attended with no bad consequence. There
is therefore no essential connexion between offensive
smells and contagion; yet, as they are sometimes united,
the absence of the smell ought not to encourage us rashly
to go into suspicious places, neither ought the presence
of it to deter us from venturing where we have otherwise
good reason to do so.
Having given up the doctrine of animalcula, the
Doctor goes on to explain the doctrine of concentrated
contagion in a manner very similar to that given in this
treatise, viz. from the decomposition of some kind of
gas. “The fœtor of the breath (says he) perspirable
matter, &c. evidently demonstrate that they differ from
the healthy state. The smell, to our senses, comes very
near what is called sulphurated-hydrogenous gas. Some
of the fluids within the body would seem to be in some
degree in a state of actual decomposition; unless we can
suppose the mucous glands of the lungs secreting a fluid
that taints the expired air in this manner. The decomposition
of the fat, which sometimes disappears very suddenly
in fevers, may give some ground for the supposition
that a large portion of these exhalations are composed
of hydrogenous gas. But, whether we can go thus
far or not, what is separated from the body, it is plain,
is more disposed to decomposition than when the
body is in health. Now this process will still go on,
whether exposed to the atmosphere or not, with this
difference, that, by exposing substances which have
imbibed the exhalations of the diseased to a free air,
the noxious gases will be dissipated as quickly as they
are evolved; while, on the other hand, by laying the
clothes in a heap, packing them firm in a chest, or
making up cloth into small bales, the gases are concentrated
into a small space; and woe to the man
who first inspires them. . . . Now this does not hold
out an idea that the powers of contagion are multiplied,
as by generation; for that would be to say, that these
gases are themselves what we call the matter of infection.
I would only go so far as to assert that they are
the vehicles of it, till more certain experience shall
determine farther.”
With respect to fumigations with nitrous acid, our author
repeatedly declares that he has no confidence in
them; nay, he brings instances where they seemed to have
bad effects. But as the dispute about fumigation has no
connexion with the true plague, nitrous acid having
never been used as a preventive for it, we shall defer any
farther consideration of it to the second part of this treatise,
to which it naturally belongs.
We come now to the fourth and last mode of prevention,
viz. a consideration of those means by which an
individual, without separating himself from society, and
who is daily obliged to have communication with the
sick, may yet secure himself against infection. Here the
means recommended are extremely various, and some of
them so opposite, that we can scarce avoid suspecting them
all. The misfortune is, that though a person should go,
without fear, among the sick, though he should constantly
take a medicine, and should never have the distemper,
yet we cannot say whether the medicine did
preserve him or not. Were it possible to know the
particular constitution of the body which disposed some
to resist the attack of the disease, attempts might be
made to bring the constitutions of others to the same
standard, but unfortunately our ignorance here is so great,
that any attempt to alter the constitution of the body
has generally proved unfortunate even in other diseases.
Dr. Lind informs us, that the first Portuguese adventurers
in Africa, having observed, that “such as had
the good fortune to escape a fit of sickness or death,
soon after their arrival, enjoyed afterwards a pretty
good state of health, thence concluded, that the blood
of such persons had been entirely changed by the diet
of the country. Upon this erroneous principle they
adopted a most fatal method of seasoning people to
these unhealthy climates. They, by small quantities,
frequently repeated, took away as much blood as they
supposed to be contained in the body, and thus they
reduced the patient to a state of extreme weakness.”
From its being observed that people of delicate constitutions
are less liable to the plague than others, such
a mistake probably has also been made with regard to
this distemper, but with equally bad success. Allen
tells us from Diemerbroeck, “Phlebotomy, though mightily
cried up by many of the ancient and modern
physicians, yet we reject it altogether, as very dangerous
and detrimental; for it appeared by experience that
those who made use of it for prevention’s sake were
seized with the plague soon after bleeding, wherefore
we forbad it to all.” This may seem surprising, as we
find bleeding so much recommended by Sydenham as
a remedy; but by others it is equally reprobated; nay,
Dr. Hodges tells us that he never knew but one who
recovered from the disease after the use of it. Issues
seem more likely, if not to prevent, at least to render the
disease more mild if it should attack. They are recommended
by Diemerbroeck, and Russel speaks of them as,
“by some authors, represented as almost infallible.”
He cannot, however, recommend them from his own
experience, having never seen them opened for the purpose
of preventing the plague; and he justly observes,
that when habitual on any other account, they may perhaps
lose their effect in this. “Multitudes (says he) of
both sexes at Aleppo had issues in their arms, it being
there a very common remedy in a variety of chronic
disorders: but, notwithstanding those outlets, numbers
perished; and I did not remark that those who
had them were in any degree less liable than others to
be infected.”
Tobacco has been recommended as an excellent preservative,
particularly by Diemerbroeck, who writes with
a kind of enthusiasm in its favour. “Being called
(said he) to visit a patient afflicted with the plague, as
soon as I entered his chamber I felt a most offensive
smell of excrements (for he had a diarrhœa) with
which I was greatly affected. Leaving the house
after a very short visit, I instantly found myself seized
with giddiness, nausea, and uneasiness at the heart; so
that I had no doubt of my having caught the pestilential
contagion. Laying aside all business, therefore, I
immediately returned home, and smoked five or six
pipes of the best tobacco; by the use of which all the
above-mentioned symptoms so totally vanished, that
I felt not the least uneasiness any more. Then, being
again desirous to go abroad and visit other sick people,
I took a drachm of theriaca, and from thence-forward
was in perfect health. The same thing happened
to me three or four times during the time of
this pestilence; and without loss of time, according
to the quantity of infection I supposed that I had
taken in, I had recourse to the more plentiful use of
tobacco, by which my health was restored. I always
looked upon tobacco to be an excellent preventive
remedy, and its smoke I have sometimes found useful
to myself even in an incipient attack of the disease.131”
He then proceeds to inform us of a report that in a violent
plague at London all the dealers in tobacco were
exempted. At Nimeguen, however, they were not so
fortunate; yet of the family of the principal tobacco
merchant (Thomas Peters, an Englishman) which was
very large, none were infected, excepting only one servant
maid, and she quickly recovered.
On this remedy Dr. Russel makes the same remark as
on the issues. “The custom of smoking (says he), is
universal among both men and women at Aleppo.
This too, from its being habitually practised, might
perhaps lose part of its prophylactic virtue: at the
same time those who use it as a preservative must
always be supposed in some degree accustomed to it,
otherwise the violence of its operation on most persons,
on their first beginning to smoke, might prove
hurtful. It should further be observed, that the tobacco
commonly used in Syria is much milder than
the American, and that the oriental smokers seldom or
never spit.”
It hath been observed that the plague is stopped either
by great heat or great cold, but more readily by the
former than the latter. “It has generally been supposed
(says Dr. Canestrinus) that the cold of winter was
destructive of contagious matter; but various instances
of the contrary may be collected. The plague in
Transylvania continued through the very severe frost
in 1709. On the contrary it has been found, that
excessive heat has extinguished, or at least diminished,
pestilential diseases. During the plague at Aleppo
the weather was unusually hot in the beginning of
July, and it was remarked that the disease declined
considerably; and in general Dr. Russel observed,
that the plague ceased at the hottest season of the
year. The plague at Ockzacow, which raged in the
years 1738 and 1739, began in the month of April,
and continued with violence till July, when it declined
considerably, and entirely ceased in the month
of September; in February of the year following it
re-appeared, and totally ceased in July.”
From these facts we might be led to suppose that a
warm regimen, or occasionally exposing the body to
great heat, might be advantageously used by way of
prevention; but Dr. Russel justly observes, that the human
frame, “could it support such an application of fire
and smoke as is necessary to expel or destroy contagion
from infected substances, would probably receive little
benefit from it, if infected; nor could those in health
sustain, without prejudice, the heat and dense smoke
which is probably required for the perfect extinction
of the infectious effluvia floating in the confined atmosphere
of a morbid body.” He is of opinion,
however, that some kinds of fumigations may be of use,
and he mentions some of these, but says that the perfumes
ordered by the college are perhaps as proper as
any, though their forms might be rendered more simple.
Heat alone can scarce be thought very proper for prevention,
and, when the disease is once begun, is said to
be detrimental. Dr. Guthrie quotes Baron Ash saying,
that “in heated rooms the disease is ungovernable: it
is only in free air that it is to be treated.” But of late
a discovery has been made of a surprising power in
heated oil of removing this disease, insomuch that, if we
can believe what has been published of it, we must suppose
it to be little less than a specific. So great indeed
has been the confidence put in this method, that, by
order of the Academy of Sciences at Lisbon, it has been
translated into Arabic, French and Portuguese.132 “The
method was first proposed by George Baldwin esq.
agent for his Britannic Majesty, and consul-general at
Alexandria. He communicated his method to Lewis
de Pavia, chaplain and agent to St. Anthony’s Hospital
at Smyrna; who, after five years experience,
pronounces it to be the most effectual remedy hitherto
made use of in the hospital of which he has had the
management for twenty-seven years. Immediately
after a person is perceived to be infected with the
plague, he must be taken into a close room; and, over
a brazier of hot coals, with a clean sponge, dipped in
warm olive oil, his body must be very briskly rubbed
all over; for the purpose of producing a profuse sweat.
During the friction, sugar and juniper berries must be
burned in the fire, which raise a dense and hot smoke,
that contributes to the effect. The friction ought
not to be continued more than four minutes, and a
pint of oil is enough to be used at each time. In general
the first rubbing is attended by a very copious
perspiration; but, should it fail of this effect, the operation
may be repeated, first wiping the body with a
warm, dry cloth; and, in order to promote perspiration
still farther, the patient may take any warm sudorific
drink, such as elder-flower water, tea, &c. It
is not necessary to touch the eyes; and other tender
parts of the body must be touched gently. Every
possible precaution must be made use of to prevent
the patient from taking cold, nor must the linen be
changed till the perspiration has entirely subsided.
The operation should be repeated once a day, until
evident symptoms of recovery begin to appear. If
there are already tumours on the body, they should be
gently and more frequently rubbed, till they appear
to be in a state of suppuration, when they may be
dressed with the usual plasters. The operation ought
to be begun on the first appearance of the symptoms
of disease; if neglected till the nerves and the mass
of blood are affected, or a diarrhœa has commenced,
little hopes can be entertained of a cure; but still
the patient should not be despaired of, as, by an assiduous
application of the means proposed, some few
have recovered, even after diarrhœa had commenced.
During the first four or five days the patient
must observe a very abstemious diet; the author
allows only a small quantity of vermicelli, simply
boiled in water. Nor must any thing be taken
for thirty or forty days, except very light food, as, he
says, an indigestion in any state of the disorder might
be dangerous. He does not allow the use of wine
till forty days. There is no instance of the person
rubbing a patient having taken the infection. He
should previously anoint himself all over with oil, and
must avoid receiving the infected person’s breath into
his mouth or nostrils. The precaution to be used in
all circumstances is that of carefully anointing the
body, and living upon light and easily digestible food.
Mr. Baldwin observes, that among upwards of a
million of people carried off by the plague in Upper
and Lower Egypt, in the space of four years, he could
not discover a single oilman, or dealer in oil.” Lisbon,
July, 1797. By Royal Permission.
With regard to diet, and the use of spiritous liquors,
opinions, as may well be imagined, have been very discordant.
Allen quotes Diemerbroeck advising poor people
to take two or three spoonfuls of the best white wine
vinegar every morning, which he looked upon to be one
of the best preservatives: he recommends also the frequent
application to the nostrils of a spunge dipped in
treacle vinegar. With regard to himself he says that his
principal care was to avoid uneasy passions of the mind;
and that when he found himself any way disturbed by
these, he cheered his heart by three or four glasses of
wine: his common drink was beer, and also white wine,
small, or moderately strong, which sometimes he drank
to cheerfulness, but never to drunkenness. Dr. Patrick
Russel also says, that “a glass of generous wine, or any
other cordial more agreeable to the choice, may be
taken before dinner, in case of languor, or oppression
at the stomach, from fatigue, fœtor, or apprehension.
I found a rummer of old hock very agreeable on such occasions.”
Allen goes on to inform us from Diemerbroeck,
that, “as to diet, it is advisable in a pestilential disposition
to use temperance, which very much contributes
to the preservation of health; but all sudden changes
are dangerous; wherefore it is most dangerous suddenly
to alter the usual rule of diet. It is very ill in the
plague to go abroad with an empty stomach: hog’s
flesh is looked upon to be very pernicious: all sweet
things are to be avoided: wine moderately made use
of is good, but the abuse of it very dangerous.—Mercurialis
testifies, that among the Patavians and Venetians,
most of the tipplers died, who thought to drive
out the plague with strong wines.” Mr. Howard informs
us, that a person in high station at Constantinople,
attributed his recovery entirely to the use of green tea,
others to brandy. He also mentions a Mr. Hare, master
of a merchant vessel at Senegal, who, during the prevalence
of a malignant fever there, was very much exposed
to the infection, and who out of humanity waited upon
a negro, whom nobody would go near. He took no
medicines, neither did he taste either spiritous or fermented
liquors, and was the only European that entirely escaped
the contagion.133
These accounts seem to evince that little or nothing
is to be expected from a change of diet. This is an attempt
to change the constitution of the body, and cannot
be expected to succeed any more than bleeding.
There is a certain quantity, and a certain species, both
of food and drink, different in different persons, necessary
to preserve health, and those who require both in larger
quantity or better quality than others, are no more to be
charged with intemperance than those who are supported
by the smallest quantity of the coarsest fare. In
times of danger, therefore, those who have been accustomed
to spiritous liquors ought not to give them over;
neither ought those to begin the use of them who have
not used them before. From the account formerly
given of the structure of the human body, it appears to
be furnished with an apparatus for exhaling or throwing
out a perspirable matter as well as for inhaling or taking
in one equally subtile. How far the skin may be able
to inhale or rather imbibe surrounding effluvia, may be
doubted; but with the lungs there cannot be any doubt;
and the effluvia taken into them must unquestionably
affect the blood, and of consequence the vital principle,
almost without any medium. To deprive the body of
its due portion of nourishment therefore is to throw a
temptation in its way (if I may use the expression) to absorb
any thing; and the same effect must ensue from
any other mode of debilitating it, either by intemperance,
terror, or the like; and hence to visit infected places
while under any such debility must be very imprudent.
Dr. Russel agrees that it is a general and rational precept,
never to go abroad fasting. For those who cannot
easily bear fatigue without eating between breakfast
and dinner, some light food may be proper, at an intermediate
hour, in order to avoid going into the chambers
of the sick with an empty stomach in the forenoon.
“In such circumstances (says he) after a long and
fatiguing morning, I have often found myself disagreeably
affected in my latter visits, and have been sensible
of slight giddiness, and of the appetite flagging at
dinner, as if something lay on the stomach. I have
known others much more strongly affected in this
manner, and consequently much more alarmed. In
such cases much no doubt may depend on the fancy;
but in those times the power of the imagination
requires management. So intimately is it connected
with the accidental state of the body, that the same
risk, from which a man shrinks in a state of languor
and fatigue, he will encounter undauntedly after a
temperate meal: the strange, unusual sensations, which
amount almost to a persuasion of having caught the
infection, will often, like the phantoms of a vision,
vanish after a few glasses of wine.134 Whether any
slight degree of real infection can be thus dissipated,
I shall not take upon me to determine; it is sufficient
for the present purpose to indicate the means of restraining
those alarming sensations which, when aggravated
by imagination, are apt to depress the spirits,
and, according to the general opinion, to reduce the
human body to that relaxed, inhaling state peculiarly
susceptible of contagion.”
As to other modes of precaution, the Doctor advises
that such as are about the sick “should guard the mouth
and nostrils with vinegar, avoid drawing in the breath
while close to the bed side, or swallowing their spittle
while in the infected chamber. Before they approach
the bed in order to examine the eruptions, the bed-clothes
ought to be removed, to give time for the
dispersion of a confined steam which immediately discovers
itself to the senses; and it will be advisable
to dip the hands in vinegar before examining the
parts. On coming out of the chamber it will also
be proper to rinse the mouth, and wash the hands,
with vinegar, plain or camphorated.” He advises also
to fumigate the clothes with nitre, sulphur, and juniper
berries, burnt on a red-hot iron.
“Upon returning home it may be advisable to shift
clothes immediately, hanging those taken off upon
lines in a small chamber, to be again smoked, and afterwards
aired. The mouth and hands ought once
more to be well washed, and the hair might be fumigated
with a little nitre and sulphur, by means of a
pipe, so as not to incommode the lungs.”
One other mode of prevention, not of the disease, but
of incurring danger from it, is inoculation. This is
greatly recommended by Baron Ash above mentioned,
and not only for the plague among the human species,
but for that among cattle, which frequently destroys
great numbers of those necessary animals. The case of
Mathias Degio related p. 272, shows the practicability
and the safety of it. The only solid objection that can
be made to it is, that those who have once had the plague
are not secure from having it a second time, or oftener.
Yet, if we consider the extreme fatality of the disease
when it attacks in the natural way, and that the number
of those who have the plague only once is much greater
than of those who relapse, this practice will certainly be
found to merit consideration, and, unless some objection
to it be discovered greater than any that has yet
appeared, seems likely to be advantageous to the human
race in general.
