The principal affirmations which I have to make on this subject
are divisible into Ten Propositions, as seen in the Table
of Contents.
The first four of these concern the general conduct of medicines
after their introduction into the stomach, and before
their passage into the blood. Some broad rules are laid down
by which the course which they take must be determined.
The action of some few on the mucous membrane is also
defined.
The remaining six propositions treat of the subsequent behaviour
of those medicines which pass into the blood and
fluids of the body. Of these, the fifth specifies their general
course. The sixth states that they may undergo certain
changes in the system. And the concluding four treat of the
various modes in which these agents may operate in the cure
of disease.
The first proposition lays down the great fundamental rule
of the action of medicines through the medium of the blood
and fluids.
This is to say, that the mere contact of a medicine with the
stomach is not in general sufficient for the production of its
peculiar action. It will be seen that the only apparent exception
to this rule consists of agents having a mere local
action on the mucous membrane, for which simple contact is
all that is required.
Even when acting on any part of the system removed from
this mucous surface, as when applied to the skin, it is necessary
that the medicine pass away from it to enter the blood
or internal fluids. In the great majority of instances it
enters the blood directly. But we know that it would be
sufficient for its operation if it were to enter through the
chyle, or into the serous fluid which exists in the interstices
of the tissues throughout the body. For by these it might at
length be conducted to distant parts. This is what is meant
by internal fluids.
We are not just now concerned with the way in which this
passage into the blood and fluids is obtained. It is by the
process of absorption. The question of passage by absorption
is treated in the second and third propositions. What we
have now to decide is, whether a medicine acts by mere contact
with the stomach, its influence being propagated to distant
parts by means of the nerves; or by passage thence into
the system, acting through the medium of the blood and fluids.
I affirm that it operates in this latter way; and this is to
be proved by four considerations, which we will consider in
succession.
A medicine introduced into the system elsewhere acts in the
same way as when introduced into the stomach.
This proves at least that contact with the mucous surface
is not an essential requisite for the operation of a remedy.
We may cause a medicine to be absorbed by the skin, or
inject it directly into an opened vein. The result of this
latter experiment proves not only that entry into a distant
part of the system is sufficient for the action of a medicine,
but that it will operate when introduced into the blood.
Numberless proofs of this affirmation may be adduced. Tartar
Emetic injected into the veins produces vomiting. Croton
Oil rubbed on the surface of the abdomen causes purging.
Mercurial ointment applied by friction to the skin will produce
salivation. Extract of Belladonna applied to the temples
causes dilatation of the pupil of the eye; and tincture of
Opium dropped on the eyeball causes the pupil to contract.
Ammonia inhaled as gas into the lungs will relieve fainting
in the same way as when swallowed. The breathing of Prussic
acid, causing its vapour to be applied to the pulmonary
surface, is sufficient to kill. Prussic acid, dropped in a concentrated
state into the eye of a dog, causes speedy death.
Solution of Aconitina, applied to the skin, will produce numbness,
and tingling of distant parts. Injection of Nux Vomica,
or any powerful poison, into the veins, is rapidly followed by
symptoms of poisoning, like those which would have followed its
introduction into the stomach.[17] Thus contact with the stomach
is not necessary, but introduction into the system any
where is sufficient. But still, may not the poison in either
case act by influencing the nerves? Even when it has entered
the blood, it may not travel along in it, but act in a more
direct way. So in the second part of the proof we must show
that a remedy cannot act by an impression conducted from
the surface of the stomach by means of the nerves.
The continuity of nerve is not necessary for the propagation
of such effects; but vascular connexion is necessary.
This alone, if established, would be sufficient to prove that
a medicine must be introduced into the circulation, in order
to act on distant parts. When confined to a surface, it can
operate on the remote part only by its contact with the superficial
extremities of the nerves. For vascular connexion to be
established, it must first enter the vessels. Many experiments
have been made which demonstrate that the vessels are the
only channel by which medicinal effects can be propagated.
M. Magendie introduced some Woorara poison into the
limb of a dog, which was only connected with the trunk by
means of quills uniting the divided ends of the main vessels.
It rapidly took effect. Having divided all the nerves and
lymphatics in the intestine of another dog, he introduced into
it some Nux Vomica, beyond the division. It quickly acted,
and must again have done so through the vessels. Sir B.
Brodie cut all the nerves of the anterior extremity of a rabbit,
near the axilla, and then introduced Woorara into the foot.
It rapidly acted.[18] Thus we see that vascular connexion is
sufficient, and that nervous connexion is not necessary. By
other similar trials it is found that vascular connexion is
absolutely necessary, for when it is interrupted, the action
cannot be propagated along a nerve. If, on introducing poison
into an extremity, a cord be tightened round the limb above
it so as to intercept the flow of blood, no effect is produced.
It takes effect after the ligature is relaxed. Sir B. Brodie
introduced Woorara into the leg of a dog, which was connected
with the trunk only by means of the principal nerve,
carefully dissected out. No effect followed. M. Ehbert found
that poison would not act when applied to an amputated limb
connected with the trunk by a nerve only. Thus vascular
connexion is necessary; whereas continuity of nerve is not
necessary, neither is it sufficient by itself.[19] Woorara poison
is a substance which acts with great rapidity on the nervous
system; and if its action cannot be propagated by means of the
nerves, à fortiori would it seem that slower poisons must act
through the circulation. But, granting that it has been shown
that introduction into the stomach is not necessary for the
action of a medicine, and that when in the stomach medicines
do not act by influencing the nerves, still it may be objected
that the rule cannot possibly be universal. It may be urged
that some poisons and medicines, as Hydrocyanic acid and
Ammonia, act with such great rapidity, that we can only suppose
their influence to be transmitted directly along a nerve-fibre
to the nervous centre, because the process of passage in
the blood to this distant part would be far too slow. This
argument requires us to prove a third thing.
The circulation of the blood is sufficiently quick to account
even for the operation of those poisons which act most rapidly
by influencing the nerve-centres.
There is no poison whatever which acts so quickly on distant
parts that the circulation cannot previously have had
time to conduct it to them. By means of an instrument invented
by M. Poisseuille, Dr. Blake found that a chemical
substance traversed the whole circulation of a dog in nine
seconds, and of a horse in twenty seconds.[20] The results of
Hering were similar. M. Volkmann, in the tenth chapter of
his work on Hæmadynamics, states, as the result of several
experiments, that the whole circulation in an adult man occupies
exactly 65.76 seconds.
Now a poison that operated by nervous connexion would
probably operate directly when it touched the stomach. This is not
the case even with Hydrocyanic acid. This, the most sudden
of all poisons, before it takes effect, allows sufficient time to
elapse for the blood to conduct it to the brain. Blake made
an interesting experiment upon it. He placed some on the
tongue of a dog, having first fitted a tube into the larynx, so
as to prevent the vapour from passing into the lungs. The
effect did not commence until sixteen seconds had elapsed,
and forty-five were required for its completion. This allowed
of time for absorption.
Thus it is proved that poisons act when introduced into the
system at any point; that vascular connexion is required for
this action; and that the rapidity of the circulation is in all
cases quick enough to account for it.
But this last is only a proof of possibility, and does not by
itself show that a substance may not nevertheless act through
the nerves. And to the experiments on nervous connexion
some may object that no conclusions on this point can be
drawn from trials made on isolated and exposed nerves. So
we may imagine a person to be still incredulous as to the
truth of the Proposition, that medicines must pass into the
blood before they can act. But a fourth consideration will
suffice to bring this probability as close as possible to a
certainty.
The great majority of medicines have been detected in the
blood, and found in the secretions formed out of it.
Having tried to prove that they must pass into the blood,
if we find that they actually do so, we shall establish a stronger
case. Isolated observations on this subject have been frequently
made. Thus in 1847 Mr. Allen detected Daturia in
the urine of a man poisoned by Stramonium. In 1824 M.
Runge had discovered in the same way the principles of Henbane
and Belladonna. M. Ragsky has lately detected Chloroform
in the blood. (Journal für Prakt. Chem. 1849.) Dr.
Golding Bird observes that Indigo, when given for Epilepsy,
has turned the urine blue; that Logwood also passes into it,
and causes it to give a dark precipitate with solutions containing
iron; and that during a course of Copaiba or Cubebs, a
resin may be precipitated from it on the addition of Nitric
Acid. If a medicine cannot be proved to pass into the blood
or secretions, we cannot so certainly affirm that it does not
act through the nerves. But the experiments of Tiedemann
and Gmelin, and since then of Wöhler, have definitively settled
this point. The former two have found the great majority
of mineral, and many vegetable substances, in the blood
of animals to which they had been administered.
Thus, from these four considerations, we are strictly justified
in concluding that a medicine must pass from the stomach
into the blood before its action can be manifested. This action
cannot then be conducted from the surface of the stomach
through the agency of the nerves. Some experiments made
by Dr. Garrod and others on the action of animal charcoal as
an antidote, furnish again an additional confirmation of this
fact. He finds that if a sufficient quantity of this absorbing
agent be introduced into the stomach before time has been
allowed for the passage of a medicine through the mucous
membrane, then even such powerful nerve-medicines as Morphia
and Strychnia, in very large doses, are prevented from
taking effect. Yet before the contact of the charcoal they
would have had time to act through the nerves, had they been
capable of any such action.
In the fifth Proposition the rule here laid down will have
to be further extended. It will be shown that medicines,
having already passed into the blood, must travel along in it
so far as to reach the part of the system on which they act.
Before concluding this question, a few remarks must be
made on a subject which will be again referred to in the discussion
of the Fourth Proposition.
The proper and peculiar action of a medicine, by which I
mean that action on the system which is immediately recognised
as distinct from that of any other agent, cannot be
exerted on distant parts from the stomach-surface, but requires
the passage of the medicine into the circulation. But can any
other action on distant parts be produced by the remedy while
in the stomach? This is a different question, and must be
answered in the affirmative. Suppose a Cantharides plaster
be applied to the surface of the chest in a case of Pericarditis,
so as to redden or blister the skin, absorption of the fluid in
the pericardium may follow this application. But any other
irritant would have done this. It is not the proper or peculiar
action of Cantharides, but an operation of the nervous
system which follows the local change. Such agents are said
to act by Counter-irritation or Revulsion, because it appears
that, as a consequence of their action, the attention of the
nervous system may be drawn off from a morbid process going
on at some other part of the body. But it is only a consequence,
and not a direct operation. Such an effect is no more
the action of Cantharides than the healthy functions following
recovery from sickness can be ascribed to the remedy
which has cured the latter.
Now some few medicines have a marked local action on the
mucous surface of the stomach and intestines. (Vide Prop.
IV.) These, and these only, may, without passing into the
blood, produce on distant parts an action of this kind by
counter-irritation. Thus the operation of an irritant emetic
may be followed by the arrest of some incipient inflammation,
e.g. Ophthalmia. This revulsive action, when carried to an
extreme, so powerfully impresses the nervous system, that
it puts a stop to all other actions, and produces Syncope or
Death. This extreme action is called Shock. Powerful corrosive
poisons may effect this by a sudden destruction of the
mucous surface, operating like a surgical injury. But such
actions, not being the proper and characteristic operations of
medicines, but rather attributable to a change in the relations
of the nervous system, following a local impression, are not to
be considered as exceptions to the above rule, that medicines
cannot from the surface of the stomach or intestines propagate
their influence to remote parts.
It has already been shown of medicines in general, that it
is necessary for them to pass away from the mucous surface
into the circulation. Mention has been made of their discovery
in the blood by chemical means; and as we proceed it
will be shown more particularly of different sets of medicines
that each of them has been found in that fluid. Now, to gain
entrance there, the medicine must first pass through the soft
mucous membrane lining the stomach and intestine. This
passage is performed by a process to which the names of Absorption
and Endosmosis have been applied. Immediately
outside this membrane, and between the tubes and cells which
are formed by its involution, is a close net-work of very small
veins, having thin and delicate walls. Now the same forces,
whatever they be, which conduct the medicinal solution through
the mucous membrane, cause it to pass on through the fine
walls of these vessels. The two membranes, lying in such
juxtaposition, are to all intents the same as one. Thus the
medicine passes into the blood, and this is the only direct way
by which it can gain entrance into it. These small veins, or
capillaries, lead at length to the Mesenteric veins, which pour
into the Portal vein, by which the blood proceeding from them
is conducted into the Liver. The process of Absorption is the
only mode by which remedies can thus enter the blood; we
have now to consider what it is, and to show in what manner
and by what agents different medicines are fitted to undergo it.
The subject of this Proposition divides itself naturally into
three parts. We shall have to consider—1. What is the nature,
and what the function, of the gastric and intestinal secretions.
2. The laws of this process of Endosmotic absorption,
and how they are fulfilled in this case; and, 3. The mode
in which the great majority of medicines are reduced to a state
of solution, which is necessary before they can be absorbed.
The process of stomach-digestion has been cleared up of late
years by the decisive experiments of Spallanzani and Réaumur,
of Tiedemann and Gmelin, and of Dr. Beaumont of Canada.
Immediately that a substance touches the mucous surface
of the stomach it causes the copious outpouring of a thin fluid,
which is secreted by a glandular apparatus. This gastric juice
is highly acid, and contains besides a peculiar nitrogenous substance
called Pepsin. Dr. Prout thought that the reaction
was due to free Hydrochloric acid. But it seems more likely
that it is due to Lactic acid. Such at least is the opinion entertained
both by Liebig and Lehmann. Now the result of
the action of this fluid is to dissolve down the solid materials
of the food, or other substances presented to it, reducing them
to a thin watery pulp. This pulp is then mainly absorbed;
and that which is not taken up through the coat of the stomach
is absorbed in the earlier portion of the intestinal canal. I
shall have to treat of Aliments as one of the orders of Restorative
Hæmatics.
We are now concerned with medicines in general. The
same juice is poured out to receive them. Such as are dissolved
by it are immediately absorbed. Some other matters
may be rendered soluble by the agency of the Bile and Pancreatic
juice which are poured out into the middle of the Duodenum.
The former is an alkaline fluid, containing carbonate
of Soda. The Pancreatic juice is also said to be alkaline.
That the stomach is absorbent may be proved by the experiment
of placing a ligature round the intestine of a dog, just
below the pylorus. It is then found that soluble substances
placed in the stomach pass rapidly from it into the circulation.
It is probable that all substances which are easily dissolved
pass through the coats of the stomach. That the surface of
the intestines is absorbent may be proved by the disappearance
of enemata thrown into them. Liebig states that a solution
of common salt, in the proportion of one part to eighty of
water, disappeared so completely in the rectum that an evacuation
one hour afterwards was found to contain no more
than the usual proportion of salt. (Animal Chemistry, p. 77.)
On the mucous surface of the small intestines are a number
of small projections, called Villi. Within these are the origins
of the Lacteals, a peculiar set of Lymphatic vessels, which are
engaged in the absorption of chyle. This chyle is a thick
fluid which is formed by the meeting of the Bile and Pancreatic
juice with that part of the digested food which passes into the
Duodenum. It is generally white, from the presence of fat.
Now these lacteal vessels are no doubt absorbent, but are they
ever engaged in the absorption of medicinal solutions? It
seems that they are not in ordinary cases at all concerned in
this; for three chief reasons. In the first place it appears
from the researches of Bernard and others that the lacteal
system is a special arrangement for the absorption of fatty
substances, and that other matters, such as albuminous compounds,
pass generally into the veins, and thence to the liver.
Besides, it seems that these lacteal absorbents are only in
action during the digestion of food, when the epithelium on
the surface of each villus becomes loosened, in order to allow
to the chyle an easier access to the lacteal within it.[21] So
that it is likely that a small portion of a fluid or soluble substance
would be insufficient to rouse them to action. And, inthe third place, direct experiments of a decisive kind have
been made on this point. Magendie has found that the ligature
of the lacteal trunks does not prevent the occurrence of
poisoning from agents introduced into the bowels. And
Tiedemann and Gmelin have carefully sought in the chyle for
a number of different medicines administered to animals in
their food, and have been unable to detect any of them there.
So that, with the exception perhaps of fats and fixed oils, we
may reasonably conclude that no medicinal substances pass
into the system through the lacteals, but that all are absorbed
by the veins or capillary vessels.[22]
It seems probable that the Bile and Pancreatic juice may
be engaged in reducing to a soluble state certain medicines
that are insoluble in the Gastric secretion, and may thus
procure the absorption of these substances by the veins of the
intestinal canal.
Having briefly considered the secretions which meet the
medicine on its first entrance into the system, we are next to
inquire into the manner in which this medicine gains admission
into the blood. In the first place, it must be in a fluid state,
or it cannot be absorbed at all. It will be most convenient
to consider afterwards how different remedies are to be reduced
to this condition.
Now the force or process by which fluids are enabled to pass
and repass through an animal membrane, has been named by
Dutrochet Endosmose and Exosmose, according as the current
tends inwards or outwards.
There are fluids on both sides of the membrane. The circumstances
which determine their passage are mainly five.
1. The densities of the liquids: other things being equal, the
lighter of the two tends to pass through to the heavier, more
than the heavier to the lighter. 2. Their attraction for the
intervening membrane.—That one passes through most which
has the greatest affinity for the membrane. 3. The affinity of
the fluids for each other.—A fluid passes through more rapidly
when it is readily taken up and dissolved by that on the opposite
side. By virtue of the last two laws, but contrary to the
first, water passes through to alcohol more rapidly than alcohol
to water. 4. The motion of the fluid on one side promotes the
passage through of that on the other, because it is carried off
as fast as it permeates the membrane. This also will cause
endosmosis in defiance of the first law. This may be proved
by a simple experiment. Let a large vein, cleanly dissected,
be attached at one end to the stopcock of a vessel containing
pure water. Let it then pass through a basin containing a
strong solution of Ferrocyanide of Potassium, and let the other
end hang over a jar filled with a solution of the Sesquichloride
of Iron. If the cock be now turned, and water be allowed to
pass through the vein into the vessel beyond, the solution of
Iron will quickly acquire the tint of Prussian blue; for the
heavy solution in the central vessel has passed through to the
simple water of the vein, mainly by virtue of the motion of the
latter. It will be seen directly that this is a matter of considerable
importance. 5. The last law is, that any pressure
on the fluid on one side of the membrane has a powerful influence
in determining the passage of the current from that
side. (Vide Liebig's Animal Chemistry, p. 72; Liebig on the
Motion of the Juices; and the Lectures of Professor Matteucci
of Pisa.)
The mucous membrane and the coat of the capillary vessel
beyond it are probably subject to about the same physical
conditions of absorption as those which are thus found by experiment
to regulate the passage of fluids through dead animal
membranes.
As to the first condition, it is probable that the aliment or
medicine which is digested, however solid and dense, may be
diluted down by the gastric juice until the solution is of less
specific gravity than the serum of the blood. With the second
law we are not so much concerned, as the medicine after solution
has generally no repulsion for the animal membrane. So
also with the third, as the serum of the blood mixes readily
with all watery fluids. The fourth, viz. the condition of
motion, is of great importance; for by it the motion of the
contents of the capillary vessels will tend powerfully to determine
the passage through of the liquid on the other side.
Fifthly, the influence of pressure on endosmosis is one which
is certainly exerted in the case of the stomach and intestines,
which are muscular, and during the process of digestion contract
on their contents with considerable force. This contraction,
together with the circulation of the blood in the capillaries,
would doubtless be sufficient to determine the passage of the
digested matters inwards, even in opposition to the first law.[23]
Under the first proposition I have shown that the majority
of medicines are absorbed into the system. It is now seen
where and how they are absorbed. But it still remains to be
seen what particular substances or classes of medicaments are
thus taken into the blood, and whether while so passing they
undergo any modifications.
The following, then, are the chief classes which I believe
to undergo solution and absorption in the intestinal canal.
They comprise the great majority of all substances used either
as food or medicine:—
1. Mineral substances soluble in water.
2. Mineral substances soluble in acids.
3. Mineral substances soluble in alkalies.
4. Vegetable products soluble in water.
5. Animal and vegetable substances rendered soluble by the gastric juice.
6. Fatty and resinous substances soluble in alkali.
1. All soluble mineral substances—acids, alkalies, salts, and
soluble compounds of the earths and metals—are absorbed in
the stomach and intestines. The conditions and the process
of absorption have been already stated. When solid they are
first dissolved, when in a dense solution diluted down by the
gastric fluid before they are absorbed. Thin watery liquids
are quickly taken up. Motion on one side, and pressure on
the other, hasten the process. I am not inclined to make any
exception to this rule. This leads me to make some remarks
on the Endosmotic theory of the action of saline purgatives.
M. Poisseuille found that the serum of the blood would pass
through an animal membrane to a solution of Sulphate of Soda
of greater specific gravity. He thus concluded that an ordinary
saline purgative of greater specific gravity than serum
(1.028) acted by causing the passage of this serum outwards
into the intestine, producing a watery evacuation. The theory
was taken up by Liebig and Matteucci, and by Laveran and
Millon. Dr. Pereira and Dr. Golding Bird have drawn some
practical inferences from it.
It is said that when a saline is absorbed it produces diuresis,
and no purging; that when it purges it is not absorbed; that
when given to act on the kidneys, the solution should be so
diluted as to contain less than five per cent. of the solid; and
when administered as a purgative, the specific gravity should
be considerably above 1.028. Now I do not deny that a weak
solution is more likely to pass off by the kidneys, and a dense
one by the bowels; but I consider this due to the fact, that
the kidneys are the proper emunctories of water, and of such
matters as are soluble in it. But I believe that these solutions
are equally absorbed, both heavy and weak, and that the
purging or diuretic effect depends mainly on the quantity of
the salt, as the kidneys will not eliminate beyond a certain
amount of it. I must allege, to support this view of the
question, firstly, some arguments à priori; and secondly,
some experiments which I have made to satisfy myself. To
consider first the former. Analogy is certainly against this
theory. Other purgatives from the vegetable kingdom produce
their effect when injected into the blood, and are yet often
powerfully hydragogue. What effect on the process of endosmosis
can be exerted by Castor or Croton oils, or by calcined
Magnesia? On turning to what we know of the theory of
digestive endosmosis, we find that the solid parts of the food
are diluted down so as to be absorbed, and that the influence
of pressure is to be taken into calculation. It was laid down
by the great Boerhaave that a necessary requisite for the formation
and absorption of chyle was the contractile force of the
viscera. (Van Sweiten's Comment, vol. i. p. 290.) This, in
fact, would press the fluid into the absorbent vessels, even if
against the other endosmotic forces. Further, a fundamental
principle was insisted on by Dutrochet—that even when the
liquids on the two sides varied in density, they would both
pass through to each other, though in different proportions.
The ultimate result of this would be, that a heavy saline
solution would be diluted down to the specific gravity of the
serum, and would then pass through. This point I have illustrated
in my first experiment. Thus it seems that my view is
favoured by these physical laws. But even if it were not so,
I should not be inclined to admit that all the endosmotic processes
in the living body were regulated by merely physical
tendencies. This cannot be the case with some of the secretions.
The bile is of higher specific gravity than the serum of
blood. Urine in health is lower, but in diabetes often much
higher. The production of these secretions, differing in density
from the serum of blood, would be inconsistent with the first
law of endosmosis. Lastly, we find that in many known cases
the theory which I am contesting does not hold good. Seidlitz
water and sea-water are both known to be purgative. In both
the specific gravity is below that of the serum of blood.
The first, according to Bergmann, has a density of 1.006.
It contains in each pint 192.8 grains of solid matter. Out of
this, 180 grains consist of Sulphate of Magnesia.
Sea-water has a specific gravity of 1.026, and its solid contents
are about 3.5 per cent. But Dr. G. Bird says that less
than five per cent. of saline matter constitutes a liquid diuretic.
These, then, are strong reasons against this idea considered
merely as a theory. But it can readily be put to the proof.
With this purpose I have made the following experiments.
As far as they are concerned, they seem to show that salines
are in all cases absorbed, and that whether they are subsequently
excreted through the kidneys or by the bowels depends
more on the quantity administered than on the degree of dilution
of the dose.
Exp. 1.—A sufficient quantity of white sugar was dissolved in four
ounces of water to raise its specific gravity to 1.028, that of the serum
of the blood. Two drachms of sulphate of magnesia were dissolved
in another ounce of water, so that the solution measured nine fluid
drachms, and had a density of 1.060. This heavier solution was introduced
into an open wide tube, closed completely below by a clean
piece of bladder. It was introduced into a small vessel containing the
solution of sugar, and arranged so that the height of the two liquids
should correspond. After three days, the inner solution measured two
drachms more, and the specific gravity had sunk to 1.050. The outer
solution, after making up exactly the loss by evaporation, was found to
have risen in density to 1.040. On adding a small quantity each
of the solutions of phosphate of soda and carbonate of ammonia, a
copious precipitate took place, indicating the presence of magnesia.
Thus it appeared that the fluids passed both ways, some of the heavy
solution of magnesia finding its way through to the lighter solution of
sugar. The tendency of this process was evidently to an equalization
of their densities, both by endosmose one way and by exosmose the
other. Thus, apparently, would it be with a saline purgative, and
with the serum of the blood.
Exp. 2.—Three drachms of Sulphate of Magnesia (a very mild purgative
dose) were dissolved in ten ounces of water, and thus administered
to a healthy young man. It produced, after some time, slight purging,
and some diuresis. The urine, when tested, contained only a very
little more than the usual quantity of magnesia. The quantity in the
dose was less than five per cent. of the solution, and thus, according to
the endosmotic theory, should have produced no purging.
Exp. 3.—Six drachms of the same salt were given in eighteen ounces
of water to the same patient. After a few hours, it caused very copious
and long-continued watery purging. The urine did not seem to be
increased, and contained no excess of magnesia. It seemed, that in
spite of the dilution, the quantity of the salt was so large, that it could
not pass off by the kidneys, and so was eliminated from the blood by
the bowels, in the same way as other purgative medicines. (Vide
Chap. IV.)
Exp. 4.—This trial was the reverse of the last. Two scruples of
Acetate of Potash were dissolved in three drachms of water, and thus
administered. The solution then contained about twenty per cent. of
the salt. According to the endosmotic theory, it should have caused
only slight purging, on account of its density. It did not do so, but
produced diuresis. The dose was so small, that after absorption it was
easily eliminated by the kidneys.
These experiments are in favour of my views, and seem, as
far as they go, to cast discredit on the theory of Poisseuille.
It will be very easy to multiply them, so as to place the fact
beyond a doubt.[24]
This point being so far settled, and there being no
physical reason why any other soluble mineral substance
should not be absorbed—it being, moreover, proved, by
repeated experiments, that they all pass into the blood, we
therefore proceed to the second class of bodies capable of
absorption.
2. Mineral substances soluble in acids.—It is apparent
that if any insoluble substance will admit of easy solution in
the fluids of the stomach and intestines, it may be brought
to the condition of a soluble one and thus absorbed. Now
the gastric juice is acid. This secretion has been variously
ascribed to free hydrochloric, acetic, phosphoric, and lactic
acids; also to an acid phosphate or lactate of magnesia.
There seems to be most reason to conclude that it is lactic
acid, which would be easily formed out of the constituents of
the food.[25]
But we have now only to regard the gastric juice as containing
a free acid. This would reduce to solution the carbonates
and oxides of all the metals; less perfectly when
anhydrous, more easily when in the hydrated form. In this
manner are absorbed the oxides of Iron and Silver, the carbonates
of Lime and Magnesia, and other medicines of the
same kind. They would be slightly modified, being absorbed
in combination with the (lactic) acid of the stomach. In this
they would differ somewhat from the substances already soluble,
which would probably be absorbed unchanged, unless
we except the alkalies and their carbonates, which might be
similarly decomposed. Even these, if given in solution, would
probably be absorbed faster than the gastric acid could be
secreted to neutralize them.
Other insoluble substances, such as calomel and metallic
sulphurets, would be more or less dissolved by the action of
this acid. But as a great part would necessarily escape its
influence, being propelled onwards by the muscular contraction
of the stomach, it follows that insoluble substances of
this kind are much less active as medicines than similar compounds
introduced in a soluble state. It is also likely that
a certain quantity would be sufficient to exhaust for a time
the acid gastric secretion.
We now pass on to a third class of mineral products, which,
though insoluble both in water and in acid, yet, being soluble
in alkalies, appear to be in this way prepared by absorption.
3. Mineral bodies insoluble in water and in acid, but
soluble in alkalies.—These remain unaffected by the action of
the gastric juice, but on passing on as far as the centre of the
duodenum, they meet with two alkaline fluids. These are
the bile and the pancreatic juice. We know that some such
insoluble bodies pass into the blood. It will be shown in the
proof of the next Proposition, that they cannot do so without
being first dissolved. Therefore, there must be in the intestinal
canal something capable of thus dissolving them. For
this purpose these two alkaline secretions are well adapted.
As an example of such mineral bodies, of which there are not
many, I may adduce sulphur. It unquestionably passes into
the blood, and is found there in combination with alkalies, as
a sulphuret or sulphate. It has been detected in the urine of
those who were taking it, by Dr. Ronalds and others. It is
possible that iodine, bromine, and some of the hydrated metallic
oxides; may enter the blood in the same way.
4. Vegetable substances soluble in water.—These would be
absorbed with more or less readiness according to their degree
of solubility. They would probably be taken up in great part
by the stomach. Some vegetable matters—as Lignine, or
woody fibre, and Resins—are insoluble in water. Starch even
is comparatively insoluble, and thus comes under another division,
being probably one of those vegetable substances which are
rendered soluble by the aid of the pepsin of the gastric juice.
These soluble vegetable matters are of several kinds. Cane-sugar
and grape-sugar are readily soluble. So also are the
various vegetable acids. There is another class of bodies which
is highly important in a medical point of view. These are the
natural salts of the vegetable alkaloids, of which are constituted
so many of the active principles of plants. In pharmaceutical
operations we are enabled, by the judicious employment of
different menstrua, to extract from the crude and inert mass
these vegetable active principles, and thus to obtain in a concentrated
form the medicinal power for which each plant is
esteemed. This process is also performed in the stomach.
By digestion and concoction, with or without the aid of acid,
it is enabled to dissolve out these soluble and potent matters
from the ligneous and bulky tissues which surround them.
For though the alkaloids themselves are in general almost
insoluble in water, yet their natural salts which occur in the
vegetable kingdom are mostly very soluble. The most important
of these salts are as follow. In Cinchona bark, the
Kinates of Quina and Cinchonia. In Opium, the Bimeconates
of Morphia and Codeia. In Nux Vomica, the Igasaurate of
Strychnia. In Aconite, the Aconitate of Aconitina. In Colchicum
and Sabadilla, the Supergallates of Colchicia and
Veratria. There are some neutral soluble substances, not
partaking of the nature of Alkalies. Thus we find in Ipecacuanha
and Ionidium, Emetine; in Tea and Coffee, Caffeine;
in Willow-bark, Salicine; and the soluble active principles of
Senna, Aloes, and Gentian, are probably of the same nature.
Many other alkaloids are known. Atropia in Belladonna,
Daturia in Stramonium, and Hyoscyamia in Hyoscyamus,
occur in combination with Malic acid. Conia in Hemlock,
and Nicotia in Tobacco, are peculiar volatile alkalies containing
no Oxygen: thus in two respects they resemble Ammonia.
They too are soluble in water.
Alcoholic and Ethereal fluids may be enumerated here as
soluble products of the vegetable kingdom. Alcohol mixes
with water to any extent; and one part of Ether is soluble in
ten parts of water. Nitric Ether and Chloroform are also
sufficiently soluble. So is Creosote, 1.25 parts of which dissolve
in 100 of water. But this may be absorbed in another
way, as will be seen presently. Volatile Oils and Turpentine
come also under this head. They are all slightly soluble in
water. The former, when given in small doses, are probably
absorbed in this way. Turpentine, when given in large doses,
may perhaps, by undergoing a change, come under the head
of vegetable substances dissolved by alkalies. Camphor may
be included here: one part is soluble in 1000 parts of water.
The soluble gummy matters of plants, when added to the
substances enumerated above, constitute an aggregate which
is called the watery extractive of a vegetable product: i.e.
that part which is capable of being dissolved out of it by pure
water.
But there are other active parts of vegetables, such as oily
and resinous matters, and some neutral acrid principles, which,
before they can be dissolved by water, require the aid of an
alkali. These will be considered separately.
We now arrive at a fifth class of matters which are taken
up by absorption.
5. Animal and vegetable products dissolved by the gastric
juice.—The most important of these are the nitrogenous and
nutritive constituents of the flesh of animals and of the parts
of vegetables. Albumen, Glutine, Fibrine, and Caseine, are
connected together as compounds of Proteine. Animal Fibrine,
and the analogous Glutine of vegetables, are quite insoluble
in water. Albumen and Caseine, though soluble,
are immediately precipitated by acids. This is known to be
at first effected by the gastric juice on their entry into the
stomach. But the action of the gastric juice which contains
an acid, and a peculiar nitrogenous material called Pepsin,
—together with the temperature of the body, which is about
100°,—causes at length the gradual solution of these previously
insoluble matters. This is found to take place out of the body
when the above conditions are imitated with an artificial gastric
fluid. The result of the process is a viscid fluid, which is
then absorbed. The hard Gelatine of gristle and bone is not
soluble in water at this temperature, but is readily soluble in
the acid gastric juice. The Pepsine seems to be an important
agent in this process, for an acid by itself is found to produce
an imperfect solution. The nitrogenous matters thus digested
and absorbed constitute that portion of the food which is of
most use in the nutriment of the system; for the starchy
compounds cannot be appropriated to the more solid tissues,
although in some cases they may be converted into fat, as in
herbivorous animals. (Liebig's Animal Chemistry, p. 113.)
Starch itself is one of this class. Tiedemann and Gmelin
found that by the action of the gastric juice it was slowly converted
into Dextrine, which afterwards changed into grape
sugar. Both of these are very soluble. From the researches
of Bouchardat and others, it appears that other fluids, as the
Saliva, the secretion of Brunner's glands, and the Pancreatic
juice, possess also this power of converting starch into a more
soluble compound. So that if any of it escape the action of
the stomach-secretion, it is probably reduced to solution and
absorbed in the small intestine.
This change of starch is the first of a series of transformations,
now ascertained, the ultimate result of which is its combustion
and resolution into carbonic acid. Thus the nitrogenous
compounds are called the nutritive, and the starchy
materials the calorifacient elements of the food. Considered
as medicines, these substances belong to the division of Aliments.
6. We have already considered some few mineral substances
which are absorbed by the aid of the free alkali contained in
the Biliary and Pancreatic secretions.[26] The sixth kind of
absorbed matters consists of some vegetable and animal products
which can only be rendered soluble by a similar agency.
Fats and oils, resinous matters, and some principles resembling
resins, come under this head. Fats and fixed oils
consist of acids, as Stearic, Margaric, and Oleic, insoluble in
water, in combination with a base, Glycerine, which, when
isolated, is soluble. With a free alkali such a fat forms a
soluble salt, called a soap, and the base Glycerine is set free.
In Man the Bile and Pancreatic juice are discharged together
into the middle of the Duodenum. The fatty matters of the
food are not absorbed before they meet with these secretions.
But, after they have mixed with them, a milky fluid, called
chyle, is formed, which is then taken up by the lacteal absorbents.
It passes thence into the Thoracic duct, meeting there
with an albuminous lymph, and is discharged at length into
the general circulation at the junction of the left jugular and
subclavian veins.
M. Bernard, in some papers laid lately before the French
Academy, states, as the result of his experiments, that the
function of the Pancreatic juice is to reduce the fat to the
condition of a white emulsion. He states that no milky chyle
is formed when the Pancreatic ducts are tied in dogs. He
considers it absolutely necessary that saccharine and albuminous
matters should be absorbed by the capillaries of the
Portal veins, and then pass through the liver; and believes
that the sole function of the lacteals is to take up fat thus
emulsified. His experiments and inferences have received
the high sanction of M. Magendie.
M. Frerichs has since affirmed that, whatever be the function
of the Pancreatic juice, the Bile, by virtue of the alkali
which it contains, is an indispensable agent in the absorption
of fats. But M. Bernard has also found that the Pancreatic
juice is always alkaline in health.
Whatever be the particular function of the Bile, it may
reasonably be concluded that the alkali contained in one or
both of these fluids is engaged in the saponification and solution
of the emulsified fats. If it were not for this, this alkali
would seem without an object; and further, it is contrary to
all we know of the process of absorption to suppose that oil
could pass through to a watery fluid without the intervention
of an alkali to reduce it to the soluble state.
Thus it would seem likely that by means of the Pancreatic
juice, with or without the aid of the Bile, fatty matters are
first emulsified, in order to undergo an increase of surface,
and then again saponified before they can be absorbed by the
lacteal villi.
The principal fixed oils which are used in medicine are
Castor, Olive, Almond, Croton, and Cod oils. It is certainly
to be regarded as a very beautiful arrangement in the animal
economy, that those substances which are not acted upon by
an acid fluid should be subsequently subjected to the action of
a free alkali, so that by the successive action of these solvents,
together with the peculiar process of stomach digestion, the
great majority of substances taken into the system are dissolved
and rendered fit for absorption.
There seem to be other vegetable substances which are rendered
soluble by means of alkali in the way already described.
Resins form an important class of remedial agents, in which
are comprised many Diuretics, Diaphoretics, and Purgatives.
They consist chemically of peculiar acids, which, though themselves
insoluble in water, combine with alkalies to form salts
which are soluble. They are certainly in most cases absorbed.
They have been found in the blood, and detected when passing
out in the urine. From this last they may be precipitated by
an acid, indicating that they are held in solution by an alkali.
In large doses they may not be absorbed, but by irritating the
surface of the intestinal canal, may act externally as Cathartics,
and be expelled by the peristaltic action which they excite.
But in small doses they enter the circulation in solution, and
affect remote organs. The only way in which they can be
dissolved is by means of the alkali of the two intestinal fluids.
Among resinous medicines I may mention Catechu, Kino,
Benzoin, Storax, Peru and Tolu, Copaiba, Guaiacum, the fetid
resins, etc. Many purgative drugs, as Jalap, Scammony, and
Gamboge, owe their efficacy to resin.
There are moreover certain neutral acrid principles, similar
in their nature to resins, which are soluble only in alkalies,
and thus come under this head. Such are Cantharidin,
Piperin, Pyrethrin, Colocynthin, Elaterin, and Capsicin, obtained
from Cantharides, Pepper, Pyrethrum, Colocynth,
Elaterium, and Capsicum. But it should be observed that
some of these are soluble in Acetic acid; and if, as some have
supposed, this acid exist in the gastric juice, then they might
be dissolved in the stomach.
We may add here some medicines which were enumerated
also in a former division. Creosote, not very soluble in water,
is easily dissolved in a free alkali. This substance also, like
the last, is soluble in Acetic acid.
Some volatile oils, especially Turpentine, display a marked
tendency to oxidize into resins; and being themselves very
sparingly soluble in water, may perhaps be dissolved after
having undergone this change. Thus Turpentine changes into
common Resin, which consists of two isomeric acids, Pinic
and Sylvic.
Turpentine = C20H16
Pinic Acid = C20H15O2
and,
C20H16 + 3O = C20H15O2 + HO.
or, Oil of Turpentine, with the addition of three atoms of
Oxygen, produces Pinic acid, i.e. Resin, and an atom of water.
Now Turpentine, when given in large quantities, irritates
the surface of the intestinal canal in man, and is not absorbed.
But in the horse very large doses are found to pass through
the system into the urine. It is not likely that a large quantity
should enter in solution in water. It seems more probable
that it may first in some way become oxidized, and then dissolved
as a resin. The action of turpentine resembles that of
some other substances which contain resin, as Copaiba and
Balsam of Peru.
The resins thus dissolved would pass, like other solutions,
through the mucous membrane of the intestines into the Portal
capillaries.
But of the fats and fixed oils it cannot be said to be proved
that they are absorbed in a state of solution, although such a
conclusion is almost forced upon us by a consideration of the
laws of endosmosis. They do not pass into the veins, but are
taken up by the lacteal absorbents. They are capable of solution,
and are thus not in that sense an exception to the rule of
Prop. II. But in another sense they are an exception to it;
for they do not pass directly into the veins, but through the
lacteal system. It seems that the sole purpose of these lacteal
vessels is to absorb fats. Thus it appears that all soluble substances,
whether in the food or given as medicine, and in
whatever manner rendered soluble, whether by acid, by alkali,
or by stomach digestion, are absorbed in the stomach and intestines.
All of them, with the exception of fatty matters,
pass directly into the blood, traversing the mesenteric and
Portal veins, to reach the liver. From this organ they pass
on into the heart through the Vena cava inferior. I have shown
also that they are mostly absorbed without material change.
Supposing the stomach acid to be lactic, it would be too weak
to displace mineral acids. It would, however, decompose a
few insoluble matters, and combine with alkalies and their
carbonates, forming salts which in the blood would again
change into carbonates. (Vide Prop. VI.)
It may at first sight be objected to this proposition, that
fatty matters may probably enter the lacteals in an undissolved
state. But this is not proved; and besides, whether dissolved
or not, we know that they are soluble in one at least of the
intestinal juices—viz. the Bile. So that they do not come
under the above definition.
We have just seen that many medicines which are given in
the insoluble form are capable of being dissolved in the fluids
of the intestinal canal. This so much reduces the list of perfectly
insoluble medicines, that it is difficult to find any that
come under such a definition. But Charcoal, the simple metals,
woody fibre, and Nitrate of Bismuth, will serve as examples.
Sulphate of Lead is often quoted as perfectly insoluble; but
this is not the case. It is soluble in a solution of acetate of
ammonia. This salt is contained in the perspiration. Thus
the sulphate, when substituted for the carbonate in some lead
works at Paris, proved fatal to the foreman, who died of colic.
M. Flandin found that it poisoned a dog when rubbed into the
skin as ointment. Even some metals may possibly be brought
within the influence of weak acids when in a fine state of subdivision,
as Mercury in blue-pill. Gold in a very fine powder
has been used successfully in syphilis.
Thus the list of insoluble substances is still further reduced.
But there is no doubt that many substances which are slightly
soluble in the intestinal fluids may in great part escape this
solution, and pass out with the fæces just as they went in.
To assert that the particles of an insoluble substance cannot
pass through the homogeneous wall of the capillary or absorbent
vessels, is merely to state what follows from an absolute
physical law, and is generally admitted by physiologists.
But even this fundamental datum has been lately attacked.
Professor Œsterlen of Dorpat has been induced to affirm
the possibility of the absorption of insoluble substances, from
some experiments which he has made. Finely-powdered charcoal
was administered to rabbits for some days. They were
then killed, and globules of charcoal, measuring from 1/6000 to
1/3000 of an inch, were found in the blood of the Portal circulation.
(Zeitschrift für Rationelle Medizin, 1847.) To obtain
these results the microscope was used, a far less certain
test in such matters than chemical analysis. Œsterlen reasonably
concludes that, if charcoal can so pass, so also can
any other insoluble substance. The necessity of solution
could then at once be done away with, and the blood continually
liable to admixture with all kinds of heterogeneous and
crude materials. Œsterlen asserts further that he has found
minute globules of mercury under the skin after rubbing in
mercurial ointment. (Journal für Praktische Chem., No. IX.
1850.) Now, if these things were true, there could be no
need to suppose the solution of insoluble active medicines, for
they would be enabled without difficulty to pass through in
an undissolved state.
To test for myself the accuracy of such statements, I have
made some experiments, the object of which is to discover if
some of the most insoluble of our known remedies, which
are yet known to obtain entry somehow into the blood, could
do so while yet in the insoluble state. They are as follow:—
Exp. 1.—Ten grains of calomel were given to a large dog. It was
killed after three hours, allowing this time for digestion. A considerable
quantity of blood was collected from the Portal vein, and submitted
to analysis to determine whether it contained any compound of Mercury
in an insoluble form. The blood was dried and pulverized. The
result was boiled for some time in water, and the insoluble part collected.
It was dissolved in a small quantity of aqua regia, and the
clear acid solution placed in a test tube. A slip of zinc foil was folded
round a narrow plate made of gold foil, and introduced into the solution.
A galvanic current being thus set up, the minutest quantity of
mercury, if present, would have been deposited on the gold, so as to
tarnish it. But this did not take place, and when at last the zinc was
completely dissolved, the gold remained as bright as before. Thus there
was no Calomel, or compound of mercury, present in the insoluble
form.
Exp. 2.—Ten grains of strong mercurial ointment (containing half
its weight of metallic mercury, with some oxide) were given to another
dog. He was killed after the same time, and the Portal blood analyzed
carefully in the same way, but here also no mercurial compound was
present in the insoluble form.
Exp. 3.—To a third dog five grains of Oxide of Silver were administered.
After three hours he was killed. The Portal blood was
dried in a water-bath, and reduced to powder. This was boiled for
some time in water, which was separated by filtration. Aqua regia was
then boiled on the insoluble part. This would convert any silver into
chloride. The acid was evaporated off as much as possible, and the
solid remainder heated in a small porcelain crucible to dull redness.
The result was powdered, and digested in liquor ammoniæ. It was filtered,
and excess of nitric acid was added. There was not any precipitate.
Had chloride of silver been present, it would have been dissolved
by the ammonia, and precipitated by the acid. Thus no insoluble
silver compound was contained in the blood analyzed.
Exp. 4.—Ten grains of sulphur were administered in the same way
to a fourth dog. On killing it and opening the body, the thoracic duct
was found to be full. A considerable quantity of chyle was collected
from it. Now, as it is asserted by some, that fat passes undissolved into
the chyle, and as I believe that sulphur is digested in the neighbourhood
of the bile duct, this chyle was chosen for analysis in preference to
blood, as more likely to contain any insoluble sulphur. Besides, the
blood would be less satisfactory, on account of the large quantity of
albumen and fibrine contained in it, both of them also containing sulphur.
The insoluble part of the chyle was obtained in the same manner
as with the blood. It was then boiled in a small quantity of a weak
solution of caustic potash. By this any free sulphur would be converted
into a soluble sulphate of Potassium. The solution was filtered, and a
few drops of a solution of the Nitro-prusside of Potassium added. (This
is a salt lately discovered by Dr. Playfair. It is a delicate test for soluble
sulphurets, with which it strikes a deep purple colour.) No change
was produced. Therefore no insoluble sulphur was present in the chyle.
The results of these experiments are thus in direct opposition
to those of M. Œsterlen, and support a view of the
question which seems even à priori more philosophical and
reasonable than that which he has adopted. I believe that no
insoluble medicine can in any way gain entry into the blood
without first undergoing solution in some way or another.
A. Irritant Emetics.
B. Stomach Anæsthetics.
C. Irritant Cathartics.
It has already been shown, during the consideration of the
first proposition, that medicines which act on distant parts
of the body must be, and are, absorbed before they can so act.
This necessity for absorption has been shown to extend even
to medicines which act most rapidly on the nervous system.
If any medicines could produce a distant effect by a mere
contact with the coats of the stomach, such a power would
be ascribed to those stimulants and sedatives which, from
the suddenness of their action, are called diffusible. Such
are Hydrocyanic Acid and Ammonia. Their rapidity of
action is to be ascribed to their volatility, whereby they spread
over a large surface, and are almost suddenly absorbed and
transmitted through the blood. But Hydrocyanic Acid may
be absorbed from any surface. It is poisonous when inhaled
into the lungs. It rapidly causes death when dropped into
the eye of an animal. So also the results of the inhalation
of ammoniacal gas are the same as of the ingestion of its
solution. I believe that the latter, on account of its diffusibility
and rapid absorption, escapes neutralization by the
stomach acid, and passes into the blood as free Ammonia.
In the consideration of the first Proposition, I endeavoured
to point out that though the proper action of a medicine
could in no case be conducted, without absorption, from the
mucous surface to a distant part of the system, yet that a
remote action of another kind might occur as the result of a
change in the nervous system produced by a powerful local
impression. I stated that the term Counter-irritation was
employed to express this action, the nature of it being but ill
understood. A powerful impression on any surface of the
body, external or internal, seems to be capable of arresting
and diverting, as it were, the attention of the system, and
thus, for a time, of checking a morbid process.
Frictions and Sinapisms act on the skin externally on this
principle. So do Blisters and Issues; but they are not
simply counter-irritants, for they also drain away the serum of
the blood. It is not now within my province to consider such
an action on the skin, any further than for the purpose of
stating that similar local impressions on the mucous surface
of the stomach and intestines are capable of operating on the
same principle.
We have then to consider what are the local actions that
medicines are capable of producing on these surfaces.
And first, it must be laid down as a rule, that all medicines,
when given in excess, act as irritants on the stomach and intestines.
This is more especially the case with mineral salts,
with the bitter and astringent principles of vegetables, and
with acrid and resinous matters. By irritating the stomach
locally, they cause vomiting; by causing peristaltic action of
the bowels, purging. Some of them are actually employed
to produce these effects, and will be presently specified.
The corrosive and narcotico-acrid poisons may produce by
this local action a degree of irritation sufficient to cause
death. In the case of the first, some erosion of the mucous
surface may occur. By both kinds violent vomiting and
purging is apt to be produced, and succeeded by symptoms of
collapse. These last, however, are not therapeutic agents,
when in such doses.
Antidotes, employed to counteract these poisons, are remedies
which are given to act locally in extraordinary cases.
There are three chief kinds of them; Demulcents, to sheath
the irritated surface, and protect it from further injury; Emetics
and Purgatives, to get rid of the poison; and chemical
antidotes, to neutralize it or render it insoluble while in the
stomach. With this last object, acids are given in alkaline,
and alkalies in acid poisoning. The soluble salts of Lead
may be precipitated and rendered insoluble by sulphuric acid
or sulphates. Those of Mercury, Copper, and Zinc, by albumen.
Tannic acid precipitates the vegetable alkaloids. There
are some other special antidotes of the same kind.
Let us now consider the three kinds of remedial agents in
ordinary use, which are employed for the purpose of producing
a local effect on the mucous surfaces, before absorption, or
without absorption.
a. Irritant emetics.—Two kinds of medicines are employed
to produce Vomiting,—specific emetics, and irritant emetics.
The former act from the blood; the latter, by local irritation.
In the same way that irritation of the external surface of the
body will sometimes cause at the same time the direct contraction
of a neighbouring muscle, and the reflex contraction
of others at a distance, so does local irritation operate on the
surface of the stomach. On the one hand the muscle of the
stomach itself is caused to contract, so that, the pylorus being
at the same time forcibly closed, it tends to expel its contents
in the wrong direction. On the other hand, a large set of
distant muscles is thrown into sudden action. First, a quick
deep breath is taken by means of the inspiratory muscles.
Then the aperture of the glottis is spasmodically closed, so
that, the lungs being full, the diaphragm cannot be pushed
upwards. Then immediately the abdominal muscles contract,
and being unable to act on the diaphragm, they press on the
stomach, emptying it forcibly of its contents.
All this is by reflex action, and follows sympathetically
the contractions of the stomach, co-operating with it, and resulting,
like it, from irritation of the sensitive mucous surface.[27]
Such is the action of an irritant emetic.
Now, Tartar Emetic and Ipecacuanha do not act in this way.
When injected into the blood elsewhere, in sufficient quantity,
they are found to produce vomiting. They have also special
actions on the heart and lungs, which are not possessed by
merely irritant emetics. They seem to me to act specifically
on the Vagus Nerve, which is supplied to these organs as well
as to the stomach, and to cause vomiting by deranging its
functions. By this action on the Vagus while in the blood,
they excite, in a special way, the same reflex contractions
which are produced, in the case of an irritant emetic, by irritation
of the extremity of that nerve in the mucous membrane.
They are thus Neurotics, or nerve-medicines. They
are not gland-medicines; or, at least, there is no proof that
they are excreted by the stomach, and thus they do not come
under my definition of Eliminatives. All substances which
touch the surface of the stomach cause it to pour out its secretion.
Specific emetics cause nausea, even without vomiting, depressing
the action of the heart by their influence over the
Vagus nerve. Irritant emetics scarcely cause nausea, producing
only a feeling of discomfort, arising from the inverted
action of the stomach.
The Sulphates of Zinc and of Copper; common Salt, and
among vegetables, Mustard and Horse-radish, are used as irritant
emetics. They cause, by contact and irritation, a large
quantity of the gastric juice to be poured out. This, together
with the emetic, and any contents of the stomach, is rejected.
The process is not followed by much inconvenience.
Such emetics are chiefly used when we wish to unload the
stomach of any irritating or poisonous matters; but not when
our object is to cause nausea, depression of the heart's action,
or relaxation of the muscles. The violent action which they
produce may possibly act on remote parts on the principle of
counter-irritation. Thus emetics of various kinds are often
administered in the early stages of inflammatory disorders,
and have been known sometimes to cut them short. But
such an effect is much more likely to be produced by a specific
emetic, which adds to this counter-irritant action the production
of nausea, by which the force of the heart is powerfully
depressed, and the pulse reduced. Tartar Emetic, the
most powerful of these specific agents, must doubtless be
absorbed to a certain extent before it can produce its effect.
Thus the important difference between the modes of operation
of irritant and specific emetics is, that the former do
not produce vomiting when injected into the blood, but act
locally; whereas the latter act from the blood on the nerves.
(Vide Prop. VIII., Specific Sedatives.)
b. Stomach-Anæsthetics.—There is a class of medicines used
in Gastrodynia which seem to act locally on the sentient
nerves of the stomach, in the same way that Aconite acts on
the superficial nerves of the skin. Although the majority of
them are subsequently absorbed, yet, in order to exert this
particular action, it is not necessary that they should pass
beyond the substance of the stomach itself. They do not
seem to have any special or peculiar tendencies towards the
stomach nerves. But if introduced into the blood elsewhere,
they would not pass the nerves of the stomach in so concentrated
a form as when coming directly from the mouth, and
thus would not be so useful as stomach-anæsthetics. Thus this
action depends upon local contact, and is so far a local action.
Hydrocyanic acid, Creosote, and Nitrate (also called Tris-Nitrate)
of Bismuth, are the most useful of these medicines.
The first two are subsequently absorbed, and pass into the
blood. The third is a very insoluble salt. It acts also as an
astringent on the mucous surface of the intestine, and is probably
the only astringent which is not absorbed. Being insoluble,
its action is quite confined to the mucous surface.
It may be given safely in very large doses, (as ʒss, or even ʒj.)
and it is likely that its anæsthetic action may be in some
part mechanical in nature, and depend upon its affording a
mechanical sheath to the irritable and painful surface of the
stomach. Hydrocyanic acid and Creosote,—general sedatives,—act
locally as anodynes to the nerves of the stomach.
c. Irritant Cathartics.—As there are two kinds of emetics,
differing in their mode of operation, so also do there seem to
be two kinds of Cathartics. But the distinction between them
is not exactly the same. As with the Emetics, one kind
seem to act by topical irritation, exciting an outpouring of
the intestinal secretions, and causing an expulsion of the
contents by exciting peristaltic contraction. But Specific
Emetics, which act from the blood, seem to produce their
effect by influencing the nerve of the stomach; so that they
are Neurotic medicines. Specific Cathartics act differently.
They are truly Eliminatives. They exert no influence over
nerves, but they operate by passing out of the blood through
the intestinal glands. Like Specific Emetics, they must be
first absorbed. I will not now enter into the theory of Elimination,
which I shall have to consider afterwards, but I
wish merely to distinguish between local action on a surface,
and specific action on a gland, exerted from the blood. Many
substances used as purgatives are capable of absorption, and
are absorbed. But it seems that they are not fit to remain
in the blood; and after passing round in the circulation, they
are expelled by the depurative force at a point near to that
at which they previously entered by the laws of absorption,
namely, the mucous surface of the bowels. They are most
commonly expelled by the glands of this surface somewhere
in the lower or fæcal portion of the intestinal canal, which is
more engaged in secretion, but less active in absorption, than
the upper part. The increased secretion which they excite
causes peristaltic action, which expels both it and them, so
that they cannot again be absorbed.
Such a specific Cathartic would be capable of acting thus
if introduced into the system at any point. Castor Oil and
Croton Oil, whether received into the stomach, or injected
into the veins, or introduced into the system at any part,
equally produce purging. So also do Rhubarb, Aloes, and
Senna. The principles of these medicines have been detected
in the blood by Tiedemann, Gmelin, and others. Colocynth
and Elaterium have also been proved to act specifically.[28]
It is to be inferred from analogy that other resinous Cathartics,
as Jalap, Scammony, and Gamboge, must also act
from the blood. It has also been shown that both from actual
experiment, and from a consideration of the laws of the process
of absorption, we must conclude that saline Cathartics
are absorbed into the blood before they cause purging.
But we have now to do with Cathartics that act by topical
irritation. Which are they? I believe that the same resinous
Cathartics which have the power of acting specifically,
may have, especially when in large doses, a double action.
It has been shown that resins are difficult of absorption; and
whether they be absorbed or not, we know that they must
irritate the intestinal surface, from the violent griping which
often attends their operation. Thus Scammony does not act
so well, and does not gripe, when the bowels are lined with
mucus. Gamboge and Euphorbium are irritant in an extreme
degree, and are therefore too dangerous for general use. The
powder of Euphorbium resin has been used as an Errhine,
for, by irritating the mucous membrane of the nose, it increases
its secretion. This illustrates the operation of irritant
Cathartics. A great part of the fæces is secreted by
the mucous membrane of the bowel. This secretion a Cathartic
may increase by mere contact and irritation; or, being also
a specific agent, by absorption and elimination likewise.[29]
Some Cathartics employed as Vermifuges, as the hairs of
Mucuna pruriens, metallic Mercury, and Tin powder, cannot
be absorbed at all, and must act solely and altogether by irritation.
These Vermifuges, or Anthelmintics, are employed for a
strictly local purpose—that of killing and expelling intestinal
worms. Any powerful Cathartic may be used to expel them.
But such an agent should generally be conjoined with a medicine
that tends directly to kill the parasite; for after that it
will be more easily dislodged. For this purpose the root of
Male Fern, Kousso, and the bark of the root of Pomegranate,
have been used with advantage in the case of tape-worm.
Ascarides are situated low down in the intestine, and may be
dislodged by the use of an enema, as of Salt.
Turpentine is often very efficacious in cases of this kind, being
at once a poison to the worms and a powerful irritant cathartic.
I have already alluded to Nitrate of Bismuth, as seeming
to be an astringent to the mucous surface of the intestine,
although apparently incapable of absorption. It has been
used with advantage in diarrhœa, and is highly recommended
by Dr. Theophilus Thompson in the diarrhœa of Phthisis.
But all other astringents are absorbed; and when they
act on the mucous glands of the intestines, it is probably
from the blood.
It has been supposed by M. Poisseuille and others that the
action of Opium in confining the bowels is to be attributed
to a power of checking the process of endosmosis, said to be
possessed by a solution of Morphia. I shall afterwards state
my reasons for discrediting this explanation. (Vide Chap.
IV., Art. Opium.)
Thus we have concluded the list of substances which seem
to act locally on the mucous surface, without passing into the
blood.
Having previously endeavoured to explain the various modes
in which medicines are absorbed and pass into the blood, and
having now defined the action of some few before absorption,
the greater part of our investigation remains still to be accomplished.
The actions of medicines in the blood, and their
various and complicated operations in the cure of diseases,
have to be traced out, and, if possible, accounted for.
The remaining six Propositions concern the behaviour of
medicines after their passage into the blood. The first two
of them are comparatively unimportant. The Fifth is merely
an extension of the First Proposition,—in which the same
rule is applied to the blood which was there proved of a surface,—and
indeed follows in part from the latter. The Sixth
Proposition defines three kinds of changes which certain medicines
are liable to undergo during their stay in the system.
That there are two possible exceptions to this rule:
a. The production of sensation or pain at a distant point.
b. The production of muscular contraction at a distant
point.
We might already have concluded that, as a general rule,
it is impossible for medicines to exert their primary action on
a remote part by nervous or any other agency, but that they
must actually reach the part which they affect by means of
the circulation. The experiments, already quoted, of Magendie,
Blake, Ehbert, and others, show that even those medicines
and poisons which tend most powerfully to influence the
nervous centres, cannot act by nervous connexion, or without
being allowed to pass on in the blood. They must actually
reach the brain, before they can act upon it. The circulation
of the blood is sufficiently quick to allow of this.
The action of nerve-medicines when applied to a part, being
similar to that which follows their absorption, would alone
render it highly probable that in the latter case they reached
the part in the blood. Thus Morphia, Hydrocyanic Acid,
Chloroform, and Aconite, benumb the superficial nerves:
Belladonna dilates the pupil; and Strychnia augments muscular
irritability; whether locally applied, or administered
through the stomach.
Neurotic medicines have even been detected after death in
the parts and organs which they influence. Thus Alcohol has
been found in the brain, and Lead in the spinal cord and
muscles.
From these various facts we may conclude that however
near these remedies may be brought to that part of the nervous
system over which their power extends, whether it be
centre or periphery, they do not in general affect it, unless
they are allowed to reach it.
And what is proved of nerve-medicines holds good still
more obviously with medicines that act on the blood, and on
blood disorders. Nearly all of these have been found to exist
in the blood, and to pervade the whole mass of the circulation,
wherever at first introduced.
The glands of the body form a third case in which we require
proof of actual local access. This matter will be discussed
when we have to consider the subject of Eliminative medicines,
when I shall attempt to show that the majority of
those medicines actually pass through and are excreted by the
glands which they affect. When Mercury is chemically detected
in the secretions of the liver and bowels; Sulphur in
that of the skin; Turpentine and Copaiba in that of the kidneys;
it is evident that these substances must have reached
bodily the glandular organs to which their action is directed.
Astringents are medicines which from the very nature of
their action—apparently a chemical one—cannot operate at
all without touching the muscular fibre, which they cause to
become contracted.
But in laying down this rule of the necessity of local access
for the production of the primary[30] effect of a medicine, we
must be careful that we do not make it too absolute. In saying
that no action at all can be propagated by the agency of
the nervous system, we do not make proper allowance for the
vital properties of nerve-fibre. The vital nature of common
nerve-fibre is such that two actions can be conducted along
it;—an impulse producing sensation, or an impulse producing
muscular action, at a distant point. It is known that an
impression on the terminal extremity of a sensory nerve is
capable of producing either sensation or motion at a distance,
by what is called reflex nervous action. Though this impression
must pass through the brain or spinal cord, yet these
centres are not appreciably affected by it. Now it is possible,
though it does not often happen, that the action of a medicine
on the extremity of a nerve may cause this distant action,
without reaching the part at which it is manifested. It may
be positively affirmed that in no other case can the direct
action of a medicine be conducted along a nerve.
Having made allowance for the physiological characters of
nerve, we must also take notice of the vital properties of muscular
fibre. We sometimes find, especially in the case of unstriped
muscle, that when one part of a muscular organ is
caused to contract, a wave of contraction is propagated along
the fibres; and this action may even be extended to a neighbouring
muscle, either by contact or sympathy. In one or
two cases it seems that muscular contraction may occur in
this way as the result of the action of a medicine.
We will now consider separately the two exceptional cases.
a. A medicine may occasionally produce pain or sensation
at a distant part, without reaching that part. We often find
that a morbid action at one part of the body is capable of producing
pain or uneasiness at another distant part by a reflex
nervous action. We are familiar with instances of this among
the symptoms of disease. The pain in the knee which occurs in
disease of the hip-joint; in the left arm, in some cases of heart
disease; and in the right shoulder, in disorders of the liver;
are examples. Certain impressions on the surface of the stomach
may cause such a reflex pain. Swallowing a piece of
ice will sometimes produce pain over the brow; and it is likely
that the headache which follows over-eating, or a large dose
of a tonic medicine, may result in a similar way from mere
irritation of the stomach. Any irritant, as a solution of Iron,
Arsenic, or Zinc, will do the same. The action of a violent
purgative will cause headache while it lasts. Although we
cannot deny the possibility of other actions of the same kind,
yet there are so few medicines which, in ordinary and safe
doses, are capable of producing pain in any way, that it becomes
difficult or impossible to adduce a satisfactory example
of an agent which operates on distant parts in this manner
when in the blood.
b. A medicine may occasionally produce muscular contraction
at a distant part, without reaching that part. This may
be done in two ways; either by a reflex nervous action, or by
a propagation of the contraction from one muscle to another
in its neighbourhood. The first of these never results from
the action of a medicine while in the blood; but it may follow
an impression on a surface. Thus we have already seen
that the irritation of the mucous membrane of the stomach,
and probably of the filaments of the Vagus nerve distributed
in it, which precedes the act of vomiting, may cause the contraction
of the muscles of the abdomen.
The propagation of contraction from one muscular organ
to another appears to take place in the case of violent purgatives,
particularly some, as Aloes and Savine, which act on
the lowest portion of the large intestine, exciting it to a peristaltic
contraction,—whose action may thus be extended to
the contiguous Uterus in the female, causing it also to contract.
This renders the employment of such medicines dangerous
in cases of pregnancy, as tending to produce abortion.
In other cases these agents may be useful; for by the irritation
and congestion which follows this action on the Uterus,
they may cause the appearance of the menstrual secretion
when deficient or retained. This also is the result of an
action on a surface.
Now, though in such cases the action of a medicine seems
to be continued from the part where it is situated to a distant
point, there are certainly no authenticated examples of such
an action by a remedy in the blood. Yet it would not be
reasonable to deny the bare possibility of such a thing. But
such instances are at all events rare, and, being cases of the
manifestation of their vital properties by nerve and muscle,
rather than of the proper action of a medicine, must not be
considered to invalidate the above proposition, which, as a
general rule, is of considerable importance.
a. Of Combination.
b. Of Reconstruction.
c. Of Decomposition.
Before advancing to the consideration of the modes in
which medicines operate in the cure of disease, it is of importance
to mention that some of them are liable to undergo
changes in the animal organism, because in particular cases
these changes may materially affect their action, and in all
cases they have some bearing upon it. With a view to this
point I have divided these changes, somewhat arbitrarily, into
three kinds,—of which the first does not hinder the effect of
a medicine—the second may alter it slightly—and the third
entirely changes or neutralizes it. Some of these change
have to be considered more at length in the progress of the
Essay, so that here I will only give an outline of them.
Changes of Combination.—The chief, and indeed almost the
only way of detecting changes in medicines, is by taking
notice of their effect upon the composition of the secretions.
Now in the blood we have a slight excess of alkali; in the
urine, an excess of acid. Acids and alkalies are often given as
medicines; and as it is not right that there should be much
excess of either in the blood, both are generally soon neutralized
in the system, and reduced to salts. This may sometimes
occur before absorption, but perhaps more often after
it. Now, it may seem strange for me to say that this neutralization
does not destroy their influence. But it evidently
does not; for in being neutralized they diminish in the blood,
and in the system generally, the quantity of basic or of acid
matter, and thus tend to alter the reaction of the secretions.
Though an acid may combine in the blood with Soda, or with
salts of Soda, yet by so doing it causes an excess of some
other acid, probably an animal acid, which, being set free,
acts on the secretion of urine much in the same way that the
first acid would have done. It is easier to render the urine
alkaline than to make it acid, for two reasons; first, as I shall
show hereafter, an acid may pass out through other glands
besides the kidneys; and secondly, an alkali is not so easily
neutralized, either before or after absorption, the blood being
already more or less alkaline.
A large quantity of acid would easily overcome the feeble
reaction of the blood, and thus, by remaining free, Sulphuric
and other acids are enabled to act as astringents on certain
of the glands.
Other changes of combination have already been shown to
take place during the process of absorption. Alkalies and
their carbonates are more or less neutralized by the stomach
acid. Substances soluble in alkalies are probably absorbed in
such solution. Calomel, Chalk, Magnesia, and metallic oxides,
as well as other insoluble medicines, are taken up in the
soluble form, in which only they are capable of acting. But
we are now concerned with medicines in the blood. And here
I must protest against the idea that all chemical affinities
have free play in that liquid. If it were so, many of our
most valuable medicines would be decomposed and rendered
insoluble there. All the mineral salts would be precipitated
by the free Soda in that fluid. Acetate of lead would be immediately
decomposed by sulphates, and Nitrate of Silver
precipitated by chlorides. It is probable that the vital forces,
as well as the viscidity of the plasma, exert a retarding or
controlling power over such chemical tendencies.
Some substances are decomposed while passing out of the
body. Decomposing matters in the intestines and in the
saliva, cause the formation of Sulphuret of Iron, while chaly-beates
are taken, which blackens the fæces; and of Sulphuret
of Lead, when lead is taken for some time, producing the
well known blue line on the gums.
Changes of Reconstruction.—The elements of a body may
be disturbed in the system, and combined together anew,
without any material or apparent alteration of its properties.
Probably many changes of this kind occur, but only some
isolated instances have been verified. Thus Tannic acid, acquiring
Oxygen, changes into Gallic. Benzoic and Cinnamic
acids are converted into Hippuric acid, which passes out in
the urine. Turpentine changes into a volatile oil, which communicates
to the urine an odour of violets. Ferridcyanide of
Potassium changes in the system into Ferrocyanide. Some
of these changes will be afterwards considered more at
length.
Changes of decomposition.—By this I mean such a disarrangement
of elements as shall neutralize or reverse the
action of a medicine.
There is free Oxygen in the blood, and the most important
change to which all organic substances are liable there is
oxidation.
This probably occurs in many cases. It always takes place
with the starchy elements of the food, and with those parts
of the nitrogenous tissues that have done their work, and are
preparing to be excreted from the body.
By this oxidation Wöhler has proved that the alkaline
salts with vegetable acids are changed in the blood into alkaline
carbonates. From being first neutral, they become
now alkaline in their reaction, and affect the urine in the
same way as free alkalies.
(Vide Hæmatics, ord. Acida, Alkalia, Tonica, Solventia.)
We have now to treat of the actions of medicines in the
blood. These are recited in the four remaining Propositions.
The seventh treats of Hæmatics, acting primarily in the
blood.
The eighth treats of Neurotics, passing from the blood to
the nerves.
The ninth of Astringents, passing to muscular fibre.
The tenth and last treats of Eliminatives, which pass out
of the body through the glands.
1. That of these, some, called Restoratives, act by supplying,
or causing to be supplied, a material wanting, and
may remain in the blood.
2. That others, called Catalytics, act so as to counteract
a morbid material or process, and must pass out of the
body.
Supposing that a medicine has fairly passed into the blood,
and circulates round with it, there are now two ways in which
it may behave itself.
In the first place, it may have a tendency towards some
tissues or parts of the body, on which to exert its powers, as
the nerves, or the glands, or muscular fibre, and may use the
blood only as a vehicle by which most readily and easily to
attain to these. Such are Neurotics, Astringents, and Eliminatives.
They may not affect the blood, but they must
pass through it.
But there is another and still more important class of
medicines, whose action is particularly directed towards the
blood itself. The blood, after their action, is different from
what it was before. It may be a change for the better or for
the worse; but there certainly is a change. Medical authors,
with few exceptions, have been very backward to acknowledge
the existence of medicines of this description. But
even those who would fain have classed all medicines as
stimulants or sedatives, differing only in the kind or degree
of their action on the nervous system, have in many cases
been obliged to confess that there is a set of remedies which
they call "Alteratives," whose action, though slower, is more
certain and more durable than that of the former. It is
allowed that they alter the condition of the blood. To suppose
that they do so by first influencing the nerves, is to
adopt a circuitous and uncalled-for explanation. It is proved
that they pass into the blood. It is known that when actually
applied to nerves, they do not affect them. From these
considerations merely, without further evidence, it would seem
tolerably clear that they act by influencing the blood itself,
simply and solely. But this it will be my business to prove
more at length directly.
Such medicines, then, I have designated Hæmatics, a simple
and expressive term which has been used by others before me.
It is obviously necessary that a medicine of this class should
be absorbed.
Now some of them tend in the end to act on the nerves
or on the glands, not merely indirectly, but by bodily contact.
But, whatever their subsequent action, they exert a primary
and apparent influence on the blood itself. A little reflection
will convince us that these remedies are more efficient than
any others that can be selected out of the armory of physic.
It is easy, and satisfactory for the time, to allay nervous
excitement by employing a sedative, or by using a stimulant
to communicate to the system a temporary strength. It is
easy to knock down an inflammation, or to evacuate morbid
humours, by stirring up the glands with a powerful eliminative.
But these are all at the best but temporary measures.
Unless the exigency be also of a temporary character, the
disorder may soon return with unabated violence; again is
the patient bowed down by its strong hand; again is the fatal
termination seen looming in the distance but too distinctly.
Then has the physician to call to his aid more potent means,
remedies of more permanent and certain efficacy. The disease
is in the blood—ever circulating, breeding, and destroying.
It is there that it must be met; let the physician strike boldly
and warily there, if he would effect a cure.
These medicines, then, act in the blood. How they do so,
and in what way they prove of use in the cure of disease, I
shall next have to show, while attempting to prove the proposition
in which I have briefly stated this mode of operation.
Hæmatics are very numerous, and very important: I shall
thus devote some space to their consideration. But I must
first lay down a broad distinction between the two divisions
of Hæmatic medicines. The diseases in which they are used
appear all to originate in the blood, however they may manifest
themselves.
Now some of these diseases originate in a want of some
principle or constituent of the blood, which want causes an
aberration of the vital functions.
Thus, in anæmia, there is a deficiency of the Hæmatosin
of the blood corpuscles. In simple debility a want of a similar
nature probably exists. In rheumatic fever and other disorders
an excess of acid is formed and eliminated, possibly from
a want of the alkali by which it should be neutralized. In
common inflammatory fever there is an abnormal oxidation of
the Proteinaceous compounds, possibly arising, as we shall see
hereafter, from a failure of some principles which are the
proper food of the oxygen. In diseases causing urinary deposits
there is a want of those principles which should naturally
retain them in solution. In typhoid fever there is said
to be an excess of basic matter, and a deficiency of acid, in the
blood. In pulmonary phthisis there is a deficiency of fat in
the system. In the latter stage of malignant cholera there
is an absence of watery particles in the blood. Some suppose
that in scurvy there is a want of the salts of Potash in
the blood.
These diseases, then, in some of which the want is proved,
in others partly hypothetical, may be treated by medicines
which supply the deficient matter, and thus restore a right
state of things. They may supply it to the blood directly, or
else cause it to be generated there. The former of these modes
of restoration seems to be the most frequent, and may possibly,
when we shall know more of such matters, be found to occur
in all cases. This division of Hæmatics I have named Restoratives
(Restaurantia.) Their action, as we shall see, is in some
cases apparent, in others more obscure. They restore the
blood directly to its proper condition, if there is only a deficiency,
but they do not in general seem to have the power of
counteracting any morbid or active material that may exist in
the blood. Nor do they, except in large doses, exert themselves
any peculiar action on that fluid. In these respects
they differ from the other division of Hæmatics. They also
differ in another important character. Each Restorative has
in healthy blood a substance analogous to, or identical with
itself: it replaces this when deficient.
Not so with other Hæmatics. There is in general nothing
in the blood corresponding to them—or if there be in some
cases, they are not introduced with the intention of supplying
its wants. Thus Restoratives may remain in the system, and
are intended so to do; but these may not remain. They must
pass out. In so doing they come under the head of Eliminatives,
or that of Astringents. This is their secondary action,
distinct from their primary and most important operation.
What then is the curative action of these remedies?
A large class of diseases depends on the presence in the
blood of a morbid material, or, what amounts to the same
thing, on the constant working of a morbid process in that
fluid. Some of these, as the eruptive fevers, will run a certain
course, and then come to an end. These we cannot
generally stop, but can only alleviate. But others, more in
number, and more commonly met with, tend naturally to run
on for an indefinite period, unless by any means we can arrest
their progress. Some depend on a contagious virus, communicable
from one person to another, as Syphilis. Some, as
Ague, are dependent on atmospheric or terrestrial influences.
Others are due to some derangement of the secondary assimilative
processes, as Scrofula, Scurvy, Gout, and Rheumatism.
Others again, to causes that are ill understood, as convulsive
disorders and skin diseases. Lastly, some may be caused in
many different ways, as common inflammatory fever.
Now the object in the treatment of such diseases is to
obtain in each case some remedy, that shall be able to counteract
this process, something that shall destroy the morbid
influence at work, and thus restore health. Medicines that
are used with this intention form the second division of Hæmatics,
which I have named Catalytics (Catalytica,) from a
Greek verb signifying to destroy or to unbind.
Now though I have a probable hypothesis to advance as to
the action of some of these, I would not have this considered
as more than hypothetical. I would not speak positively of
the action of any one of them, any more than to say that each
of them tends to neutralize one or more particular morbid
poisons.
Some have tried to give a general explanation of their action,
and have talked of it as if it were easily understood by their
known properties. I am not of their opinion; and when I
speak of Catalytics, I shall give my reasons for disagreeing
with them. Now each Catalytic has peculiarities and affinities
that distinguish it from all others. I have not thought that I
could arrange them more truthfully than by subdividing them
according to diseases which they tend to counteract. How
inadequately is the action of Mercury and of Iodine expressed
by calling them special stimulants, alteratives, or absorbents!
Is it not better and more correct to say at once that Mercury
is useful in checking inflammation in general, and in counteracting
the poison of Syphilis in particular? and that
Iodine is effective in secondary forms of the latter disorder,
as well as in Scrofula?
These medicines, then, are specifics, in so far as they are
particularly useful in certain disorders, and in those excel
other remedies; but they are not, in the vulgar acceptation
of that term, the only medicines which can be employed in
such a disease, nor is their use to be restricted to it alone.
I have already said that a Catalytic tends of itself to work
out a peculiar process in the blood. For this reason their
administration in health generally does harm. They have
nothing in the blood corresponding to them; or if so, they
are not introduced to supply its want. Thus they must eventually
pass out of the body. Before doing so, some may act
on the nerves. While so passing out, they may, as I have
said, act either as Astringents or Eliminatives on the glands.
Under these heads their secondary action will be subsequently
considered.
Being thus foreign to the blood, Catalytics do not remain
there to supply a want; but just long enough to counteract
a morbid action, and are then excreted.
Such is the difference between Restorative and Catalytic
medicines. Although so far as this their action is sufficiently
distinct, yet some care is required in separating the remedies
in one division from those in the other. Sometimes both
kinds are used in the same disorder. For whenever the action
of a morbid poison causes any derangement in the proportion
of the normal constituents of the blood, a Restorative
may become of use to supply this defect. Thus a cancerous
or scrofulous condition may cause a deficiency in the red
colouring matter of the blood, which may be supplied by
Iron. When, as in Gout and Rheumatism, there is an excess
of acid in the system, partly due to an absence of that
basic matter which should be present to neutralize it, this
may be restored by an alkaline remedy. In both of these
cases a Restorative may be used in a disease which depends
on a morbid agency. But other remedies, Catalytic in their
action, are of more direct use in such disorders. They counteract
the original poison, and striking at the root of the evil,
instead of correcting the consequences, they are more likely
to eradicate the disease.
Some medicines come under both heads, acting in different
ways in different cases. Thus Potash may be a Restorative
in Rheumatism, but a Catalytic in Scrofula.
The operation of some particular agents is rather obscure.
I shall have to show how it seems to me that the vegetable
acids may act as Restoratives in fevers; and also to explain
why, of those medicines which are used in Intermittents, I
have placed Quina among Restoratives, and Arsenic with
Catalytics.
It may be remarked that the fact that Catalytic medicines
produce of themselves distinct actions in the blood has proved
a stumbling-block to the disciples of M. Hahnemann. For
in some few cases their action may, to a certain extent, simulate
the disease which they tend to cure, and has thus been
confounded with it by this imaginative observer. This partial
resemblance is probably due to the fact that both disease
and remedy produce a series of changes in the same set of
particles in the blood. If it were not so, the remedy could
not meet the disease. It would be out of its province, as not
acting at all in the same sphere. But that the actions are
essentially different is sufficiently proved by the fact that
they counteract each other. The remedy, moreover, is often
of equal efficacy in other different disorders. It has been
shown in Chapter II., that with regard to Eliminative medicines,
the Homœopathic theory is founded on a misapprehension
of facts.
It must not be inferred, from what has been said on the
importance of blood-medicines, that I am disposed to agree
with those who would account for all diseases by some fault
in the humours of the body. For though we know that many
cases of convulsive disorder, as of Hysteria, Chorea, and
Epilepsy, may be reasonably accounted for by supposing the
existence of a wrong in the blood, which has affected the
nervous system,—yet there are doubtless many nervous affections
which are primarily independent of the blood, which
can only be treated by Neurotic medicines, and even then
often without benefit.
Thus far I have chiefly dealt in assertions on the subject
of Hæmatic medicines, but I am now about to attempt a thing
which is more difficult, that is, positive proof.
I shall treat separately of Restoratives and Catalytics; each
division will be divided into certain distinct orders of medicines;
and of each of these orders in turn I shall attempt to
prove what is laid down concisely in Proposition VII. To
simplify this proof, that part of the Proposition which relates
to Restoratives will be divided first into a number of minor
propositions, which, taken together, imply the original one.
Each must be shortly proved applicable to each order of
Restoratives. The same will be subsequently done with
Catalytics. Having sustained the original proposition to my
own satisfaction, I shall, in some cases, venture to offer an
additional hypothesis—only as hypothetical—on the action of
particular medicines.
Let us now proceed to the consideration of the first division
of Hæmatic medicines.
The general name given to the medicines in this division
is founded upon a fact relative to their action, which will be
acknowledged of most that I have here included—namely,
that they restore to the blood certain materials in which it is
deficient.[31]
I will divide them into six orders, which are all distinct
and characteristic in their mode of action.
| Restaurantia. |
|
| Ord. 1. Alimenta. |
| Ord. 2. Acida. |
| Ord. 3. Alkalia. |
| Ord. 4. Tonica. |
| Ord. 5. Chalybeata. |
| Ord. 6. Solventia. |
On reverting to Proposition VII., which treats of the action
of the first class of medicines, it will be seen that what
has been there stated with respect to the action of Restoratives
resolves itself into the following simple affirmations or
minor propositions.
m. p. 1.—That they act in the blood, and that their effect is permanent.
m. p. 2.—That there are naturally in the blood substances which resemble or coincide with them.
m. p. 3.—That they are not of necessity excreted, but may remain in the blood.
m. p. 4.—That they are of use when a disease depends on the want of one or more materials in the blood.
It will be seen that the first minor proposition affirms them
to be Hæmatic medicines, according to the definition given
before. The second is required; for if there were not a necessity
in the blood for substances like them, they could supply
nothing. The third also is necessary, for if they were
excreted in all cases, it is evident that their Restorative action
could not be lasting. An exception must be made in the case
of those that are used to supply something which is necessary
in order that a secretion may be properly elaborated. Medicines
of the Sixth Order are particularly used with this intent;
as also some acids and alkalies. But these are not repugnant
to the blood, like Catalytics. In the fourth place it
is affirmed that being thus fitted for the blood, and allowed to
remain in it, they tend to cure a disease which depends on
the want of a substance similar in nature to themselves.
After giving a brief account of each of the orders of Restoratives,
it will be my object to prove that these affirmations
are severally applicable to each of them.
Ord. I. Aliments.
An article of food is the simplest form, and in fact the
type, of all medicines of this division. Out of the materials
of the food the whole blood is constantly elaborated, and all
the tissues are constructed.
Aliments were divided by Dr. Prout into four kinds:—(1)
Aqueous; (2) Albuminous; (3) Saccharine; (4) Oleaginous.
These kinds differ much in chemical conformation. The
second kind alone contain Nitrogen. The last two are both
called carbonaceous; but those of the fourth kind contain
more Carbon than those of the third. The following will
serve to illustrate the differences in the chemical composition
of these groups.
1. Water = H O
2. Proteine = C40H31N5O12
3. Starch = C10H10 O10
4. Stearic Acid = C68H68O7
Water is useful in dissolving the other elements, and reducing
them to a state of solution which is fitted for the formation
of blood, and of the other fluids of the body. We
have already seen in what way these various matters are
dissolved and absorbed in the primæ viæ, and how they pass
into the circulation; that Proteinaceous and Saccharine matters
pass into the capillaries of the Portal vein, and thence
onwards through the liver; and that fatty matters are reduced
to a kind of emulsion by the intestinal juices, and pass
through the lacteals into the thoracic duct, by which they are
conducted into the circulation at large.
What then are the chief uses for which these matters are required
in the system, and what great functions do they fulfil?
The nitrogenous Aliments are needed particularly to supply
the growth and waste of the muscular and nervous tissues,
which both contain Nitrogen; as also do all the parts of the
body, excepting Fat. This waste is continually going on. It
depends upon the fact that, after having lasted a certain time,
the particles of all these tissues are gradually displaced, oxidized,
and conveyed away out of the blood into the urine and
other secretions. In the urine these waste matters are found
as Urea, Uric acid, and Kreatine.
The starchy and saccharine parts of the food are destined
to pass through a series of changes, which ends also in their
being burnt and oxidized, maintaining the animal heat, and
forming Carbonic acid. Starch passes first into grape-sugar,
by taking into itself two atoms of water, becoming C12H12O12.
The Ptyaline of Saliva, Pepsin of the gastric juice, and some
similar principle in the Pancreatic fluid, are all capable of
causing this first transformation. This sugar is more soluble
than Starch. When in the blood, it undergoes a further
change, the nature of which is not so clear. It is supposed
to be into Lactic acid (C6H5O5, HO7) whose equivalent number
is just half that of anhydrous grape-sugar, so that one
atom of the latter may become two of the former. This important
compound was found by Berzelius, in 1807, to exist
constantly in the juice of muscle, as well as in the urine and
sweat. (Annuaire, 1848, p. 347.) Liebig at first controverted
this, but in 1847 he assented to the statement of Berzelius,
which had already been further confirmed by the experiments
of M. Pelouze. Many modern chemists, among
whom may be mentioned Dr. Bence Jones,[32] consider that
Lactic acid, or some compound nearly resembling it, is formed
at this step of the process of changes connected with the
function of respiration. The acid next combines with free
Soda, existing in the blood; and this salt is oxidized into
Carbonate of Soda and water, just as a Tartrate or a Citrate
might be. (Vide page 127.) This has been ascertained by
Magnus and Dumas.
Fatty matters are used in the production and renovation
of the adipose tissues; and may also, like the last, be burnt
and oxidized to support the animal heat.
As a general rule, the diet of a man in health should contain
a due proportion of all four kinds of food; for each one
of them is essential, and has its proper function in the system.
The albuminous material cannot be dispensed with; and is
also the only food which will suffice by itself to sustain life.
The mode in which it can adapt itself to perform the office
of the other varieties of food was ill understood, until explained
by the researches of M. Bernard.
From some experiments detailed in a paper read before the
Académie Française in 1848, he concluded that the liver was
capable of actually producing sugar and fat out of Proteine
compounds. For he found sugar to exist in the substance of
the liver when none was to be detected in the blood of the
Portal vein which proceeds to it. His results have been
mainly confirmed by M. Lehmann. M. Bernard states further,
that the action of the liver is in some way essential to
the assimilation of saccharine matters; for he has found that
when sugar is injected into the veins beyond the liver, it passes
out unaltered in the urine.
Thus the process of assimilation, whether of albuminous or
of saccharine matters, is not so easy and so simple a thing as
might at first be imagined. The study of this process is of
great importance; and it appears to afford us a clue to the
causation of certain disorders of the blood, of which I shall
have to speak hereafter.
Upon the regulation of diet, one of the most important of
the duties that devolve upon the medical man, it is not my
purpose to make more than a few observations.
All kinds of food are less required by the system in inflammatory
and febrile disorders; and should then be administered
sparingly, or wholly denied, according to the severity of
the case. But in Typhus fever long abstinence would be
dangerous; the patient is in peril from extreme weakness and
inanition, and, being often totally unconscious of his natural
wants, requires to be carefully sustained by constant and
small increments of animal and farinaceous food.
Water may be given largely whenever we wish to increase
the amount of any of the fluid secretions; as the urine, to
render less likely the deposition of gravel; or the perspiration,
when it is desirable to promote it in fevers or other
disorders.
Albuminous food is always necessary in health, and is contained
not only in the flesh of animals, but in vegetable substances
in their natural condition. It is recommended to
restrict it in the management of gouty or plethoric patients.
On the other hand, animal is more easily digested than vegetable
food in many cases of dyspepsia.
In Diabetes mellitus, when a large quantity of sugar is
excreted in the urine, it is a common practice to confine the
patient to a diet of meat and gluten bread. This latter is a
tough horny material, prepared from flour from which the
starch has been separated by washing. It is thought that if
no starch be given, no sugar can be formed; but it is found
that, though both the amount of urine and the quantity of
sugar in it are diminished by this plan, yet the latter does not
wholly disappear. This may be easily accounted for, if we
admit that sugar may be formed from albumen. Water
should be given sparingly in this disease; for the more a
patient drinks, the more urine he passes, and all of the same
high specific gravity.
Fat may be given in Diabetes, for it is not proved that it
can be converted into sugar; but as the contrary seems to be
the case with albumen, and it being impossible to withhold
this, the cure of the patient by mere dieting may be considered
almost hopeless.
We have seen that Starchy and saccharine matters form an
important element of the food; and that, by combining in
the blood with the Oxygen absorbed in the respiratory process,
they are of use in maintaining the heat of the body. In
some constitutions there is a peculiar tendency to an abnormal
oxidation of these materials into Oxalic acid. It appears
likely that Cane-sugar is more liable to this change than
Grape-sugar, although it may occur with the latter. Thus
the patient is sometimes benefited by an injunction to abstain
entirely from this article of food.
Fatty matters need not be given where there is organic
disease of the Pancreas; as in that case they are not rightly
digested. This is a rare case. They are sometimes repugnant
to the stomach, from other causes.
The application of oily substances to the cure of Phthisis is
a matter of considerable importance. Of late years Cod-liver
oil has been used with more success than any other medicine,
both as a prophylactic, and as a curative agent in this disease.
When this remedy is considered separately in Chap. IV.,
mention will be made of several theories which have been propounded
to account for its mode of operation. Liebig's idea
that there is in Phthisis an excess of Oxygen in the system,
would, if sufficiently supported, serve to explain its action
when considered simply as oil. This Oxygen would consume
the Carbon and Hydrogen in the food, and prevent the accumulation
of fat. (Liebig's Animal Chemistry, part i. p. 126.)
A supply of oil might then serve to restore this fat, and
afford a sufficient pabulum to the devouring element.
Thus an attention to diet is of great importance in the cure
and alleviation of different diseases; for by this means we
are enabled, within a certain limit, to regulate and control
the composition of the blood, and through it the nutrition
of the body.
Thus are Aliments essentially Restorative, forming and
supplying the blood, and from it the several tissues, which are
destined to work and to endure, until, like all organic creations,
their turn is come to die. Then only are they excreted,
and in a different form from that in which they entered; at
that time, developing into tissues of high organization, they
now decompose and retrograde into simpler bodies; at first
fitted for life, they are now shaping for destruction. The
disease which collectively they are intended to cure is Hunger;
which is in fact a call from the blood for the renovation of its
failing constituents, a demand for fresh supply from the body,
which, because always changing, is always requiring nutriment.
Ord. II. Acids.
(Mineral:—Sulphuric, Hydrochloric, Nitric, and Phosphoric
Acids. Vegetable:—Acetic, Citric, Tartaric, and Malic
Acids.)
To this list may be added the super-salts of the alkalies,
which have an acid reaction.
Although the mineral differ from the vegetable acids in
their ultimate action, and are altogether more powerful than
them, yet in their proximate effects they are similar. They
are all soluble in water, and, when given as medicines, should
be so diluted that they can exert no corrosive action on the
mucous coat of the stomach and intestines.
Dr. Pereira lays it down as an axiom that though they all
act as acids in the alimentary canal, yet that they enter the
blood as salts. He considers that they combine with free
alkaline matters in the saliva, bile, and Pancreatic juice.
(Materia Medica, vol. i. p. 171.)
But this explanation seems to me to be calculated to communicate
an erroneous idea of their action. For supposing
first that they did thus combine with alkalies before entering
the blood, yet as more alkaline matter would then have to be
secreted to supply that which they had neutralized, they would
thus immediately increase the amount of acid in that fluid.
The action of acids in the blood is very different from that of
their salts. Sulphuric acid does not act like the sulphates
of Soda and Magnesia, nor is the action of Hydrochloric acid
the same as that of common salt. Again, we must remember
that the secretions mentioned are either neutral or barely
alkaline in their reaction, and that the acid medicine, on
passing into the stomach, would meet there with an active
absorbent surface, secreting an acid, and not an alkaline fluid.
So that it seems probable that the acid would enter the blood
as such.
Now the presence of the acid is not unnatural to the blood.
The mineral acids exist there in combination, and the vegetable
acids have an analogue in lactic acid.
The blood is alkaline; which is due either to the presence
of carbonate of Soda, or (according to Liebig) of an alkaline
phosphate of that base. So that the acid, on entering into
the blood, passes at once into combination with this alkali,
and the result of this is a general diminution of the amount
of basic matter in the system, and an increase in that of acid.
Thus a free acid may act as a Restorative in cases where there
is an excess of alkali in the blood. It may either remain in
the blood after entering into combination, or it may pass off
by the urine, supplying there the place of a natural acid, which
it leaves behind it in the system. It is on such a theory as
this that the action of mineral acids in typhoid and putrid
fevers has been explained. I do not mean to affirm positively
that there is in these cases an excess of alkali in the blood.
Although likely, it is not proved. The explanation is plausible.
Acids are used to correct a phosphatic deposit in the urine,
caused by an alkalinity of that secretion. The alkaline urine
may be secreted so, as has been observed in petechial fever by
Dr. Graves and Dr. Golding Bird, and in insanity by Dr.
Sutherland, and may also occur in diseases of the nervous
centres; or it may be caused by a decomposition taking place
in the bladder, as in chronic inflammation, or in the case of
retention of urine from any cause. In the former case the
acid may act as a corrective to the fluids before secretion; in
the latter case, after it. But it is not always easy to cause
acidity of the urine by any medicines. Mineral acids may
be excreted in other ways, and vegetable acids are liable to
decomposition in the system. (Vide page 125.)
The use of mineral acids in assisting a weak digestion
admits of a simple explanation. For whatever notion we
adopt as to the composition of the gastric juice, it is certain
that it contains an acid in excess. Now an acid medicine
would set free in the blood more of this acid which it is the
business of the stomach to furnish, and thus prove useful in
that kind of dyspepsia which depends on a failure of the
gastric secretion. Hydrochloric acid has been particularly
recommended by those who consider it to be the acid normally
secreted by the stomach.
When not wanted in the system, it seems probable that
acids pass in all cases out of the blood in the same condition
as they entered it. Thus vegetable acids act as diuretics;
and mineral, as astringents to the glands generally. The
latter, when given in excess, may prove hurtful by causing a
lithic deposit in the urine. The addition of a mineral acid to
healthy urine causes after some time a deposit of uric acid.
The action of acids on the urine is neither so constant nor
so certain as that of alkalies. In attempting to correct abnormal
conditions of that secretion, it must be remembered
that its reaction is liable to great variations in health. The
whole amount passed during a day should be examined together.
Dr. Bence Jones states that the urine is most alkaline
just after meals, and most acid when a sufficient time
has elapsed for the completion of the digestive process.
(Animal Chemistry, p. 51.)
I shall have afterwards to consider the action of the mineral
acids as Astringents; and I must now add a few words
on that use of the vegetable acids which has gained for them
the title of Refrigerants.
In febrile cases of all kinds it is often found that diluent
drinks containing the free vegetable acids, or solutions of their
salts with alkalies, act beneficially in lowering the pulse, and
in moderating the progress of the disorder. These should both
be distinguished from mineral saline drinks; for mineral salts,
from their known effects on the blood, would seem to belong
simply to my division of Catalytics. But the effect of these
vegetable acids seems to be to restore the blood to a more
natural condition, and this independently of the action of the
diluent with which they are administered. Now of this effect
there is no certain explanation, but a theory, which may or
may not be true, may be ventured to account for it. Should
it prove correct, it would seem that in such cases the free
vegetable acid acts as a Restorative; and that the alkaline salt
of this acid has at first the same action, but adds to it afterwards
a Catalytic operation. Let us then attempt to clear
up this matter.
It has long been considered probable, but may now be said
to have been proved by the researches of M. Becquerel, that
in febrile disorders and inflammations there is excreted in the
urine an excess of Urea and of Urate of Ammonia, substances
which are formed by the oxidation of the Nitrogenous tissues.
This extra-oxidation probably arises from a deficiency of that
matter which is the proper food of oxygen in the system.
This, as we have seen, being the step between grape-sugar
and Carbonic acid, must either be Lactic acid, or something
similar to it. It must be remembered that no food is usually
taken in fever; this would at length quite cut off the usual
source of this lactic acid, which is the starch and sugar of
the food, and render it necessary that the animal tissues should
continue to undergo oxidation, to maintain the animal heat.
Now if we compare the commonly received formula of Proteine
with those of Lactic acid and Tartaric acid, it will at once
be seen, as was pointed out some time ago by Dr. Murray,
that the latter contain more Oxygen, in proportion to their Carbon
and Hydrogen, than is found in Proteine, or Albumen.
Proteine = C40H31N5O12.
Lactic acid = C6H6O6.
Tartaric acid = C8H4O10 + 2 HO.
Thus, while for 40 equivalents of Carbon, Proteine contains
only 12 of Oxygen; Lactic acid contains 40, and Tartaric
50, of that element. So it seems that Albuminous matters,
containing less Oxygen, would require much more Oxygen
for their combustion; this would produce more heat, augment
the number of respirations, and keep up the fever. And though
it has been proved by Wöhler that free vegetable acids pass
out in the urine without having undergone oxidation, yet
the condition of fever would probably be an exceptional case.
Lactic acid, the natural fuel, being deficient, the alkali with
which it should combine must be present in some excess; so
it seems likely that a free vegetable acid would combine at
once with this alkali as the Lactic acid would have done, and
thus be burnt or oxidized instead of the latter. Its action
would then be simply Restorative. Requiring less Oxygen
than the Proteine would need to transform it into Carbonic
acid, it would thus diminish the number of the respirations,
the frequency of the pulse, the temperature of the body,—and
in this way allay the fever. It would be strongly confirmatory
of this idea if it were proved that the amount of Urea and
Urates in the urine is actually diminished by the use of acid
drinks and fruits in febrile cases. This hypothesis can only
be admitted on the supposition that fever constitutes an
exception to the general rule that the vegetable acids pass
through the blood without undergoing change.
Now, the salts of these acids, with alkalies, which are often
administered in the form of effervescing draughts, might exert
the same refrigerant action. But there would be this difference:
the alkali of the blood would not be required, the acid
being already combined with an alkali. M. Wöhler has
found that these vegetable-acid salts always undergo oxidation
in the system, being converted into carbonates or bicarbonates,
and thus reacting on the secretions as alkalies. And
so in the same way it seems that the natural lactate of soda is
formed into a carbonate, the carbonic acid being afterwards
freed from the base, to be excreted by the lungs. But by this
natural process the quantity of alkali in the blood would not
be increased, nor would it be augmented by the action of a
free vegetable acid. But the change undergone by a salt of
this acid would continually add to the alkaline matter already
in the system. Now, alkalies have a Catalytic action on
the blood, which may prove useful in some sthenic fevers;
and therefore these salts have a double action, and are not
simply Restorative. (Vide Alkalies; Antiphlogistics; Antiscorbutics.)
Rheumatism and Gout differ considerably from other fevers,
both in their nature, and in the remedies which they require.
They are produced by special morbid poisons or agencies,
which we are enabled to counteract by certain Catalytic medicines.
There is in both of them an excess of free acid
formed in the system. Remedies which are apparently opposed
in nature have proved useful in these complaints. On
the Restorative plan, alkalies are the remedies required; for
they neutralize the acid. But in spite of this excess of acid,
some of the free vegetable acids have been used with advantage,
particularly in rheumatic cases. We shall have hereafter
to consider how far this operation resembles the common
refrigerant action of these remedies just now considered.
(Vide Antiarthritics.) Some obscurity rests upon the subject
of the use of Citric acid in scurvy; but as it seems to partake
rather of the nature of a Catalytic than of a Restorative action,
I have placed Antiscorbutics in the second division.
Now, though there are possibly some exceptions, yet in
most cases Acids act as simple Restoratives; but Alkalies certainly
operate as Catalytics in some disorders, and have thus
to be included in both divisions of Hæmatic medicines.
Ord. III. Alkalies.
(Potash, Soda, Ammonia, Lime, Magnesia;—their Carbonates,
and neutral Acetates, Citrates, and Tartrates.)
We have to consider the alkalies now as Restoratives—treating
of those cases only in which they are used to restore
a wanting material to the blood or fluids of the body.
That they pass into the blood, is proved by their solubility,
and their appearance in the secretions; and that they are
natural to it we know, because they are all found in it.
Wöhler has demonstrated the curious fact that the neutral
salts of the alkalies with vegetable acids undergo oxidation
in the blood, being transformed into carbonates. (I have
just said that it seems likely that certain conditions of the
system may determine this oxidation, even in the case of the
free acids.) Thus it may be easily shown how the neutral
(bibasic) tartrate of potash may, with the addition of ten
atoms of oxygen, produce two equivalents of bicarbonate of
potash, together with four of carbonic acid and four of water.
2 KO, C8H4O10 + 10 O=2 KO + 8 CO2 + 4 HO.
_________
=2(KO, 2 CO2) + (4 CO2 + 4 HO.)
Again, one equivalent of the neutral acetate of potash, with
eight of Oxygen, will make one equivalent of the bicarbonate,
two of free carbonic acid, and three of water.
KO, C4H3O3 + 8 O=KO + 4 CO2 + 3 HO.
________
=KO, 2 CO2 + (2 CO2 + 3 HO.)
This carbonate, easily decomposed by any acid, is equivalent
to a free alkali. Thus these salts fulfil a double function.
They may supply the respiratory process, as has already been
explained. They also act on the blood, and on the secretions,
as alkalies.
Alkalies are used wherever there is an excess of acid in the
system, whatever that acid may be. Alkali should naturally
be present to neutralize it, for it is unnatural to have a large
excess of acid in the secretions, or any excess in the blood.
We thus administer alkalies on the restorative principle.
They are not always excreted; but whether excreted or not,
they tend to render the secretions neutral and alkaline by increasing
the quantity of basic matter in the system. Alkalies
being more stable than acids, and being more invariably secreted
by the kidneys, it is more easy to render the urine
alkaline than to make it acid. Alkalies are thus of use in a
tendency to lithic acid deposit. The bicarbonates are probably
the best for this purpose, for they may be given in large
doses, being less irritating. The celebrated Vichy water contains
bicarbonate of soda. Lime-water has been used as a
solvent for stone. These all act by first diminishing the acid
of the blood, and subsequently influencing the secretion of
the urine, which secretion, acting as a counterpoise to the
condition of the blood, may be generally taken as an index
to it.
Dr. Pereira recommends alkalies in cases of dyspepsia and
pyrosis, when there is an excess of acid secreted by the stomach.
He further thinks it likely that they may aid in the
digestion of fatty substances when there is a deficiency of bile.
This is quite hypothetical, and depends upon a theory which
has been shaken by M. Bernard. The same eminent authority
states that Ammonia invariably enters the blood as a salt, and
thus can exert no peculiar action beyond the coats of the stomach.
I shall state my reasons for doubting this when I
consider Ammonia separately in Chapter IV. Ammonia will
be again enumerated as a stimulant—Potash as a catalytic—and
lastly, all the alkalies as diuretics.
The alkalies are useful in gout and rheumatism in diminishing
the acidity both of the blood and of the secretions.
It is often advantageous to apply an alkaline wash locally
around an affected joint, in the fluids about which the morbid
process seems especially to have fixed itself. If we may receive
a certain theoretical explanation of these two kindred
diseases, still more light will be thrown on the advantage attending
the employment of alkaline restoratives. To this I
shall recur when I consider the Catalytics which are used to
counteract these same disorders, not, as here, by restoring a
wanting material, but apparently by determining the process
in a different direction, and thus checking it altogether.
The action of Catalytics is more obscure than that of Restoratives,
but there is generally a broad line between them.
The most difficult case is that of the medicines used in ague
and other periodic diseases; of these, for certain reasons that
I shall state, I have grouped Quina and tonics among Restoratives,
placing Arsenic among Catalytic medicines.
It seems to me that Cinchona bears the same relation to
Arsenic in the treatment of ague, as Alkalies to Colchicum in
gout; the former, in each case, supplying a needful material,
the latter neutralizing a morbid process.
Thus, when air has been rendered impure by breathing, we
may render it again respirable by adding fresh oxygen; but
still more certainly, by neutralizing the carbonic acid.
Ord. IV. Tonics.
Under this term I intend to include only the bitter principles
of vegetables. The chief medicines of this order are
as follow:
Alkaloids and neutral principles.—Quina, Cinchonia, Bebeerine,
Narcotine, Salicine, etc.
Bitter drugs.—Cinchona, Quassia, Cusparia, Gentian, Calumba,
Chiretta, Centaurium, Menyanthes, Rhubarb, Hops,
Elm and Willow barks, Tansy, Wormwood, Chamomile, Cascarilla.
The power by virtue of which these medicines are enabled
to act as Tonics, is due, in each case, to a vegetable alkaloid
or neutral principle, having a bitter taste. All of those mentioned
above, with the exception of Salicine, contain Nitrogen.
The uses of Tonics are of a twofold nature. Firstly,
they are of use in simple debility and in atonic dyspepsia.
Here they give an appetite, increase the muscular strength
and powers of digestion, and improve the general health.
In the second place, they have all, more or less, a curative
power in Ague and other periodic disorders, caused by Marsh
miasm. Many explanations have been given of this curious
and double action of vegetable bitters; and some erroneous
theories have been assumed, and false analogies attempted, in
the classification of these remedies. The subject is certainly
a difficult one, and there are, at starting, several questions
which require a distinct consideration and reply. Upon the
answers given to them it must depend whether they should
rightly be grouped with blood-medicines or with nerve-medicines;
and, if the former, with Restoratives or with Catalytics.
Do these medicines act primarily in the blood, or on the
nerves? Is their action of a permanent character? Are
there any substances in the blood which resemble them?
May they remain in the blood, or are they always excreted?
If acting in the blood, are they wont to effect a cure by supplying
to it a material wanting, or by counteracting in it a
morbid process?
These questions require each a satisfactory reply, before it
can be proved that I have done rightly in classing Tonics
among Restorative medicines; for they coincide with the
minor propositions in which I have defined the action of such
remedial agents.
Quina may be taken as the type of the whole order. It is
the most powerful; and the others all more or less resemble
it. Perhaps Cusparia bark comes nearest to the Cinchona
alkaloids in its anti-periodic action. It is worthy of remark,
that some common bitters which owe their efficacy, not to
alkaloids, but to neutral principles, as Quassia, Calumba, and
Gentian, possess the least control over periodic affections.
There can be no doubt that these active principles are all
absorbed, and pass into the blood. They may easily be dissolved
out of the vegetable which contains them, if not by
simple water, at all events by such an acid liquid as we find
in the stomach. We possess positive proof of absorption in
the case of Quina, which has been detected by Tiedemann
and Gmelin in the blood of a patient to whom it was administered.
Having them now in the blood, we arrive at the first question.
Do Quina and other vegetable Tonics act on the blood
or on the nerves? This has been answered at once by many
writers, as if it were a thing of great simplicity. But it does
not seem to be so. Tonics, as we know, have the power of
communicating health and strength in debility produced by
various causes, and also of arresting the progress of intermittent
fever. Do they effect these things by bettering the
condition of the blood, and, from it, that of the system at
large, or do they at once, and in the first place, influence the
nervous system? This is an important question, and it has
been variously answered.
Dr. Pereira, in his classification of medicines, ranks them
among Cinetics (κινεω, to move,) which are defined to be medicines
exerting a power over the motor system of nerves,
and through them on the muscles. But in a subsequent
account of Quina, he states that its action is quite inexplicable,
and that its use in Ague must be ranked with some other
special and ill-understood actions, as that of Mercury in
Syphilis, or of Arsenic in Lepra.
Dr. Neligan, (in his work On Medicines,) lays it down that
Tonics act as stimulants when given to a healthy man. Dr.
Pereira, on the contrary, states what is more consonant with
general experience, i.e. that a moderate dose of a tonic has
little or no effect on a man in perfect health. Dr. Neligan
admits that their action is permanent, and produced slowly;
he also declines any explanation of the action of Quina and
others in Ague, calling them specifics.
Some other authors have been still more decided in classing
Tonics with nerve-medicines. Dr. Guy, (in his edition of Dr.
Hooper's Physician's Vade Mecum,) considers that Stimulants
and Tonics should rightly be classed together, for that
Stimulants act as Tonics to the weak, and Tonics as Stimulants
to the strong.
It should be observed, that the irritant action on the
stomach of a large dose of a bitter medicine appears to
have been the chief foundation of this frequent opinion of
the stimulant action of tonics. The irritable stomachs of
nervous persons are more easily affected in this way. Some
too are met with who bear Tonics worse than others, on account
of an idiosyncrasy or peculiarity of constitution. But
this irritation, and the headache and febrile symptoms which
succeed to it, do not surely constitute the proper action of a
tonic medicine, which is found to operate most favourably
when given in too small a dose to produce any thing like a
stimulant effect. Nor do I think it proved that any true
stimulants are capable of communicating a permanent tone to
the system, or to any part of it.
Dr. Ballard also, (in Ballard and Garrod's Materia Medica,)
states that Tonics acts first upon the nerves, and through
them on the muscular system. He opposes them to Sedatives,
and ranks them with stimulants; quoting Strychnia as an example
of a stimulant which gives tone to the muscular system.
But, in the first place, this alkaloid is quite exceptional among
stimulants; and further, the comparison with Tonics seems
unnatural, inasmuch as the action of Strychnia is more or
less immediate, not slow and permanent, and it evidently influences
the spinal system of nerves in the first place.
The results of large doses of Quina, in producing determination
of blood to the head, ringing in the ears, and vomiting,
seem to me to mark its action as an irritant poison, and not
to be characteristic of Tonic medicines. (Vide p. 91.)
The action of Tonics has been more correctly defined by
another able authority. "Tonics," says Dr. A. Billing, "are
substances which neither immediately nor sensibly call forth
actions, like stimulants, nor repress them, like sedatives, but
give power to the nervous system to generate or secrete the
nervous influence by which the whole frame is strengthened."
This definition I would accept in a modified sense, considering
that no permanent alteration in the nervous system can
be produced without a primary impression on the blood. Dr.
Billing further considers, that the supposed stimulant action
of Tonics in some cases should either be attributed to the
operation of the disease, or of some other medicine administered
along with them; and that though in large doses they
may sometimes produce a quick pulse with headache, and in
other instances depression with nausea, yet that these effects
should be ascribed merely to their irritating action on the
stomach.
On the whole, it seems to me that those authors who, in
defining the action of Tonics, have commenced by saying that
they act on the nervous system, have started with a mistaken
notion; and I am more of the opinion of Dr. A. T. Thomson,
who classes them as medicines which act on the muscular and
sanguiferous systems.
I consider, then, that Quina is not in the first instance a
Neurotic medicine; and for the following reasons. The action
of other nerve-medicines is distinguished by the following
signs. It is quick, and very rapidly follows the administration
of a substance. It is transient, and does not endure. It
requires no particular state, but takes place in health: thus
Alcohol stimulates and intoxicates both healthy and sickly,
and Digitalis would subdue a Hercules. Most Neurotics are
capable of acting without entry into the blood at large; mere
contact with the nerves, as when they are applied externally,
being sufficient for their action on those nerves. Again,
Neurotics are chiefly used in cases in which the nervous system
is unusually excited or depressed, and are of no permanent
efficacy in diseases depending on blood-disorder. The
action of Hæmatics is of an opposite kind.
Now is the primary action of Tonics distinguished by the
above signs? Are they quick and sudden in action? Is their
effect transitory? Is it evidenced in health as well as in disease?
Do they act on the superficial nerves, when applied to
them? In each case the answer must be a negative. In all
of these particulars the operation of vegetable bitters differs
from that of Neurotics, and coincides with that of Hæmatic
medicines.
It appears that their action on the nervous and muscular
systems is secondary. They could hardly in either case effect
any permanent improvement without first acting on the blood,
if we may argue from known analogies. For Neurotics and
Astringents, which operate directly on these two systems, are
alike transitory in the results of their action.
Another demonstration is required, before the presumption
thus established can approach to a certainty.
We require proof to show that the disorders in which
Tonics are used are blood-diseases. This does not seem to
be difficult.
The condition of Debility, whatever its proximate cause,
seems always to be traceable in the first place to a want in
the blood, which interferes with the due exercise of their
functions by the nerves and other organs, by impairing their
nutrition. It follows fevers, and accompanies chronic diseases,
in both of which cases the blood has been exhausted by
continual waste and excretion, without the maintenance of a
proper supply. In cancerous, scrofulous, scorbutic, and dyspeptic
habits, the blood may be deteriorated by a fault in the
assimilative processes. When in these instances there is
marked Anæmia, iron may be of most service; but when the
blood is poor without any apparent deficiency of red colouring
matter, then are bitter Tonics needed to improve its condition,
and form a valuable adjunct to the special remedies that the
case may require. They ought not, as a general rule, to be
administered in high fever, or when the pulse is hard, the
tongue coated, or the stomach irritable. A loss of appetite,
a nervous headache, a soft compressible pulse, a quivering
tongue, a flabby condition of the muscles, with general inertia
and indisposition to exertion, are indications for their employment.
In some cases emetics and antimonials, in others
mild purgatives, are of use in preparing the system for their
reception.
It seems then that Debility is to be attributed generally to
the state of the blood; and is to be cured by improving it.
By so doing we may communicate tone to the muscular system,
improve the appetite, and increase the nervous force.
Ague, or Intermittent fever, is also a blood-disease. If it
were only from the analogy of other fevers, we might infer
this. But there are more particular proofs. This disorder
is caused by the exposure of the system to a certain peculiar
poison or miasm, which is generated in the ground in certain
places, and subject to known laws. The result of the influence
of this miasm is a process in the blood which has been
compared to fermentation, and which produces regularly recurring
paroxysms of a peculiar kind. There is apparently
some disturbance in the great calorifacient process, in which
the blood is concerned, and not the nerves. Each fit commences
with shivering; there is then a hot stage; and finally
sweating. The attack then goes off, seemingly as if the
poison that caused it were eliminated in the perspiration.
But it is not all gone. After working in the blood for a definite
period, most commonly two days, it again breaks out,
and the same train of symptoms recurs. Thus this strange
disorder, both in its origin and in its progress, appears to be
seated in the blood. So also are its results evidenced there.
Continual Ague deteriorates that fluid, causing general anæmia,
and producing more or less enlargement of the spleen,
which could only be brought about by some faulty condition
of the circulation.
Against these proofs it has been urged that the nervous
system has certainly an influence over this disorder, for that
a sudden alarm has been known to arrest it. But this may
occur also with other blood-diseases, and it does not prove
that the nervous system is at all connected with their origin.
It can hardly be supposed that Goitre or Scrofula is ever
caused by a derangement of the nerves. And yet Baron
Alibert relates an authentic case of a French lady who had a
large goitre, which for a long time resisted all treatment, but
which nevertheless disappeared entirely during the brief Reign
of Terror in the French Revolution. In addition to these
arguments it may be urged that Ague is often, if not always,
connected with deranged hepatic functions, a fact that again
points out that disease as a blood-disorder.
Seeing then that the medicines of this order of Tonics differ
in each particular of their action from those remedies which
influence the nerves directly, and that the diseases in which
they act beneficially are essentially blood-diseases, there are
sufficient grounds for concluding them to be Hæmatics, or
blood-medicines.
We have now to consider the remaining minor propositions,
which treat of their action as Restoratives; to ascertain
whether they have been rightly allotted to this division.
Are there in healthy blood any substances which resemble
them? This will appear to be a question of no small difficulty,
when it is considered how little information we have
actually obtained respecting the chemical composition of the
vital fluid. It is nevertheless desirable that we should inquire
into it to the best of our ability.
During the last few years, many propositions, intended
to throw a light upon physiological science, have emanated
from the fertile pen of M. Liebig of Giessen, who is rightly
and universally ranked among the most illustrious of modern
chemists. There are two which especially bear upon the present
subject. In his first work on Organic Chemistry (p. 182,)
he argued, that whereas the alkaloids Quina and Morphia resembled
the brain substance in their chemical constitution,
they were therefore enabled to exert a direct control over that
organ by influencing its nutrition. But it is impossible to
accept this explanation. The composition of the brain has
been since more accurately investigated, and it has been shown
to consist mainly of a mixture of albumen and fat. Now
there is no reason why these substances should have a special
affinity for albumen and fat in the brain, any more than for
the same elements in other parts of the body. There is also
no analogy at all between Quina and Morphia as medicines
beyond their resemblance in chemical constitution. The
theory seems to be altogether groundless.
Another, and a more important suggestion has been made
by the same chemist. He has pointed out a chemical analogy
between certain vegetable compounds and a substance which
exists in the bile. He has shown that for the most part the
elements of the bile re-enter the blood after passing into the
intestine, scarcely more than the colouring matter being finally
excreted with the fæces. He has found that if an enema of
bile be injected into the rectum, it becomes absorbed there,
and does not afterwards pass out into the urine.[33] (Animal
Chemistry, p. 77.) What the exact function of the bile may
be, is as yet undecided. Its most important constituents
are, a non-saponifiable fat, Cholesterine; a neutral substance,
Taurine; and an acid called Choleic, in combination with
Soda,—which latter is present in excess. Bile is bitter to the
taste; and ox-gall, or the bile of an ox, has been found, when
administered as a medicine, to have an action which resembles
that of Tonics. It appears that both the bitterness and the
tonic action reside in the Taurine.
M. Liebig has pointed out an important chemical resemblance
between this Taurine and the vegetable alkaloids. Of
these he has singled out Caffeine, the peculiar principle of
Tea and Coffee, as most analogous to the biliary product.
From the analysis of these two substances he has deduced
the following formulæ.
Taurine = C4H7NO10.
Caffeine = C8HN2O2.
Then he shows that an atom of Caffeine, if added to 9 of
water and 9 of oxygen, will form two atoms of Taurine. (Organic
Chemistry, 1842, p. 180.)
It should be remarked that a different formula for Taurine
has been arrived at by M. Lehmann and others, who assert
that it contains Sulphur. Choleic acid, and other constituents
of this complicated fluid, certainly contain sulphur. But even
if Sulphur be combined with Taurine, it is not clear that it
enters with it into the blood. And the above formula for
Taurine has been confirmed by the analysis of M. Löwig.[34]
It seems to be sufficiently correct for our purpose.
With the supposed function of Caffeine as a creator of bile,
however probable or interesting, we are not now immediately
concerned. We are engaged in inquiring whether there is
naturally in the blood any substance which resembles the
tonic alkaloids. Liebig has shown that this element of the
bile is intended for re-absorption into the circulation. And
without theorizing at all on the subject, it may readily be
demonstrated that, with the existence in the blood of such a
material as Taurine, we cannot say that we have not in that
fluid an analogue to substances like Quina. Taurine is soluble
in water, and crystallizable; is chemically analogous to
the tonic bitter principles; and contains the same four elements
as Quina. If necessary, this similarity could be exchanged
for identity, and Quina could be formed into Taurine
in the blood.
If there be one change in the blood to which, more than
to any other, the substances which enter it are liable, it is
certainly the process of oxidation. Free oxygen is continually
entering the blood through the air-cells of the lungs.
The formula for Quina is C20H12NO2. Adding to this
45 atoms of oxygen, we could make out of it one atom of
Taurine, together with 16 of Carbonic acid, and 3 of water.
C20H12NO2 + 45 O = C4H7NO10 + 16 CO2 + 5 HO.
Thus it is conceivable that this and similar alkaloids may at
the same time supply an important material to the blood,
and serve as fuel to support the animal heat, by combining
with oxygen and giving off Carbonic acid. I would not, of
course, affirm that this actually does occur; but if it were to
take place, we might gain, in this oxidation of Quina, some
clue to the production of that quickening of the pulse and increase
of the general temperature, which are affirmed by some
to follow the ingestion of the alkaloid, even in small doses.
But it is now sufficient for us if we have ascertained that
there is naturally in the system, and in the blood, a substance
which resembles Quina. We may be allowed to infer that
the presence of the latter substance in that fluid would not
be unnatural to it.
Having dismissed the second of the minor propositions
which relate to Tonics as Restorative medicines, we pass on
to the third. Are Quina and the vegetable bitters necessarily
excreted from the blood?
It is not easy to answer this question with certainty, because
it would be difficult to detect small quantities of this
alkaloid in any of the secretions. But all that is known on
the subject is in favour of a negative answer. A number of
careful and elaborate experiments on the passage of medicines
into the urine have been made by M. Wöhler, and in the
long list of substances detected by him in that secretion,
Quina is not mentioned. Neither has it been found in any
other of the secretions. The same may be said of all the
Tonic principles. There is no proof that they are necessarily
excreted, but there is every reason to suppose that they may
remain for a while in the blood.
Let us then consider the last question. Can Quina, or
substances like it, improve the condition of the blood when
deficient in any of its natural materials. We know that it is
capable of curing simple debility, ague, and remittent fevers.
It appears that it has also been successfully used of late by
Dr. R. Dundas, in large doses, in the treatment of typhoid or
continued fever. Supposing it to be proved that this agent
operates in the blood, does it remedy a disease by supplying
something wanting, or by counteracting something present
in that fluid? In fine, is it a Restorative or a Catalytic
medicine?
The probabilities which have been established, that it is not
unnatural to the blood, and is not always excreted from it, are
in favour à priori of its being Restorative. Catalytics are
generally unnatural to the blood, and are excreted because
they cannot remain in it. Besides, a Catalytic has generally
some peculiar action on the blood in health; but a Restorative,
in moderate doses, none,—only evidencing its operation
when supplying a previous want. In this also Quina and its
congeners agree with Restoratives and differ from Catalytic
medicines.
Arsenic is of use in Ague; and Arsenic is decidedly a Catalytic
in all these particulars. In other respects, too, it differs
widely from Quina. The latter is employed in debility, which
depends evidently on some want in the system, and not on any
morbid agent. Arsenic, on the contrary, is of use in Lepra,
which, like other skin diseases, must be caused by some morbid
agency, though we know not what precisely. But some
diseases may be cured in two ways; either by the supply of
something, or by the neutralization of something else. Perhaps
Ague is one of these.
And it is not repugnant to what we know of Ague to suppose
that there is in it a want of some natural material,
which would have, when present, the effect of checking the
operation of the morbid agent. The fact of having had Ague
once does not, as in the case of the Eruptive fevers, protect a
man from the disorder thenceforward. So in this sense all
persons may be said to be liable to Ague, and none protected
from its assault. But it is not the case with Ague as it is
with Syphilis and Small Pox, which diseases most persons inevitably
catch who are exposed to the virus for the first time
in their lives. For, of a number of persons exposed to the
same malarious influence, only a part take the disorder; some
escape. It is generally found that those are most likely to
take it who have been previously debilitated by any cause;
so that we must suppose that the rest have in their blood
some material which serves to prevent the working in it of
the Ague-poison, which apparently must enter it. It is not
unlikely then that Ague may be cured by supplying the want
of this material.
Coupling with this consideration those facts which have
been previously stated, we may reasonably conclude that
Tonics are Restorative, and not Catalytic in their action;
that they supply, or cause to be supplied, a material wanting
in the blood. How this material is enabled to resist the
morbid influence of the miasm—whether it is by an antiseptic
property, such as has been attributed to Quina—I cannot
determine.
Having now done my best to establish the Proposition, as
applicable to Tonic medicines, I may venture to bring forward
a speculation concerning their action, which I would
not wish to rate higher than it is worth, and still less endeavour
to demonstrate as a fact.
I have already made use of Taurine, one of the principles
of the Bile, for the purpose of showing that among the
natural constituents of the blood there is a substance which
chemically resembles a tonic alkaloid, like Quina. This
similarity admits of a further and more direct application.
It is ascertained that many, if not all, of the diseases in
which Quina and its kindred medicines are found to be of
use, are connected with a derangement of the secretory
functions of the liver. One of these diseases is the debility
which is consequent upon Typhoid and other fevers. In
these fevers the function of the liver is always more or less
interfered with, though more obviously in some cases than
in others. In strumous habits, in which generally bark is of
signal service,—and was very strongly recommended by Cullen,
Fordyce, and others,—there is very commonly a peculiar
degeneration of the liver, which has been ably described
by Dr. G. Budd. This state is distinct from the fatty enlargement
common in Phthisis, in the early stage of which
disease Quinine is also very serviceable.
Quinine is often beneficial in Gout, in which the liver is
always more or less deranged.
Turning to periodic diseases, we find that impaired hepatic
functions are the rule, and the absence of such disorder the
exception. This will be at once admitted in the case of Dysentery,
and of the Remittent and Yellow fevers of the tropics.
It is also true of Ague. It seems even likely that the enlarged
spleen may be partly caused by an obstruction to the circulation
in the liver. This affection of the spleen is not uncommon
in other liver diseases.
In Typhus fever both the spleen is disorganized and the
liver deranged. It is observed in tropical countries that severe
forms of remittent not unfrequently pass into continued fever,
which seems to point to some analogy between the two. Ague
even may pass into Typhoid fever. And I have already referred
to the fact that Quina has of late been strongly recommended
in the treatment of continued fevers in general.
Dr. Watson states that in New Zealand the biliary functions
suffer so much in the intermittent which occurs there,
that it is known among the inhabitants by the name of the
"Gall-fever." (Lectures on the Practice of Medicine, vol.
i. p. 793.)
Let us now place in conjunction with these facts the similarity
which has been pointed out between the bitter vegetable
principles, and one of the chief constituents of the re-absorbed
bile. Quina and others resemble Taurine; they tend to cure
certain diseases; and these diseases depend on deranged hepatic
functions. Does not this suggest the possibility that they may
be of service by actually forming the Taurine, or by supplying
its place in the blood? It is possible that such bodies as Quina
and Cinchonia may be able to fulfil the functions of Taurine in
the blood by remaining as they are, without even changing
into it.
It is just possible that the presence in the blood of this
bile-product, the supply of which has been cut off by the
hepatic disease, might have prevented the continual action of
the Ague-poison.
There is another fact which gives additional probability to
such an idea. Another remedy of a different kind has been
used in all the diseases in which Quina is admissible, proving
in some cases superior, and in other instances second only to
it in its beneficial action. This is Mercury; used in remittent
and yellow fevers; of the first importance in dysentery;
employed by Dr. Baillie in Ague, and pronounced by him to be
in some cases superior even to Quina. In small doses it is
frequently of use in cases of debility and scrofula. And
Mercury is a Cholagogue; i.e. an agent which is known to
have the effect of promoting the secretory function of the
liver. Thus we may conceive that Mercury, not given in excess,
or to salivation, may operate in a different way to produce
the same end as Quina. One explanation would suffice
for both.
If this connexion between Tonics and the Bile were actually
established, then we should be enabled to explain a matter
which would otherwise seem difficult to understand,—how it is
that small doses of Mercury may sometimes act as Tonics,
though we know that the ultimate action of this medicine,
like that of other Catalytics, is to deteriorate the blood.
Even in scrofulous and enfeebled cases, small doses of blue
pill or of Calomel are often signally useful; and not prejudicial,
as is sometimes stated by those who confound their
application with that of Mercury given in salivating doses.
Under such a course, when judiciously enforced, we may see
the dilated pupil contract to its normal size, and the pale
enervated countenance become rosy and lively; and feel the
weak compressible pulse to become hard and firm. Perhaps
Mercury in such a case may be indirectly tonic, by restoring
to the blood the natural tonic principle of the bile.
It will be conceded that it is a great merit in a theory,
when it succeeds in explaining at the same time a number of
different things in a plausible way. It seems that this hypothesis
of the connexion of Tonics with Taurine, or some such
element of the Bile, is capable of so doing. I am very far
from asserting that it is proved, or from supposing that it is
at all likely to be so in the present state of our knowledge of
the subject; but I think that if not evidently true, it appears
at least reasonable. And it may be observed, that even
should this idea be completely overthrown, which is neither
impossible nor unlikely, there would still seem to be left
ample evidence to prove that Quina and other vegetable bitters
act on the blood on the restorative principle,—though in
what exact way is uncertain.
Ord. V. Chalybeates.
(Protoxide, Sesquioxide, and Sesquichloride of Iron. Salts of
Iron:—viz., the Carbonate; Protosulphate; Persulphate;
Phosphate; Pernitrate; Peracetate; Ammonio-citrate;
Potassio-tartrate. Vinum Ferri. Chalybeate Waters.)
Most of these substances are readily soluble in water.
Steel wine contains a Tartrate. The insoluble oxides are
doubtless dissolved by the aid of the acid of the stomach;
and we find that both are most active when given in the form
of hydrate, which is most easily soluble in such a menstruum.
Thus Chalybeates are capable of being absorbed; and they
no doubt are absorbed. They have been detected in the
blood, and discovered in the secretions of urine and milk.
Being in the blood, they act by an influence which they
exert upon it; for they are wanting in all the characters
which distinguish nerve-medicines. They are never sudden
in their action, and the effect which they produce is lasting.
Iron is found naturally in the blood; and the substance in
which it is found is that which constitutes the colouring material
of the red corpuscles. This is called Hæmatosin. It
has been asserted by some that the red colour of Hæmatosin
does not depend upon the iron which it contains. But however
improbable this may be, it matters not here whether it
be proved so or not; for it is sufficient that it is ascertained
that Iron is essential to the chemical constitution of this red
matter. Without Iron, Hæmatosin could not exist, any more
than Albumen could continue to be Albumen, when deprived
of nitrogen.
According to the analysis of Mulder,
Hæmatosin = C44H22O5N3Fe.
It is a very peculiar body, and apparently an essential and
most important constituent of the blood; for when it is deficient,
as evidenced by the paleness of the tissues in Anæmia,
the whole system suffers materially, and great and general
debility is produced.
The result of the administration of an Iron medicine is
the restoration of this wanting colouring matter. For if the
blood be analyzed before and after its employment, it is found
to have undergone a remarkable change, most particularly in
the quantity of Hæmatosin which it contains. A case in
illustration of this is given by M. Simon, of Berlin. (Anim.
Chem., vol. i. pp. 310, 313. Syd. Society.) The solid constituents
of the blood, in a case of Chlorosis, had increased,
under the use of iron, from 128.5 to 193.5 in 1000 parts;
the Globuline from 30 to 90; and the Hæmatosin from 1.48
to 4.59, in the same amount. It is probable that the increase
in the Hæmatosin is the first change; that this then improves
the condition of the blood corpuscles, increases their number,
and through them betters the condition of the blood, and of
the system generally.
In a case which came under my own observation, the blood
of an anæmic girl was found, before the use of Iron, to contain
only 50 parts of globules in 1000, instead of 120, the
normal average. The Ammonio-citrate of Iron was prescribed,
in five-grain doses, three times a day. After it had
been continued for a month, the blood was again analyzed,
and the amount of corpuscles found to have increased to 76
parts. After another month, they had reached to upwards
of 100 in 1000 parts of blood. In the mean time the appearance
of the patient had improved immensely.
Chalybeates have thus a most immediate and obvious effect
in restoring to the blood this wanting Hæmatosin. As the
exact chemical condition of the Iron in Hæmatosin has not
been discovered, so also the precise changes which Chalybeate
medicines have to undergo before they can supply this deficient
material in a fit and proper form, are not known. All
the known soluble compounds of Iron, except the Ferrocyanide
and Ferridcyanide of Potassium, possess this Restorative
power. In most Chalybeates the Iron acts the part of
a base; but in some, as the Ammonio-citrate and Potassio-tartrate,
it exists in a peculiar condition, and cannot be precipitated
from their solutions by Ammonia. The water of
Chalybeate springs generally contains a Carbonate of Iron,
held in solution by an excess of Carbonic acid. The same
salt is contained in the compound Iron mixture and pill of
the Pharmacopœia, when these are rightly prepared.
When the Iron has entered the system, it is not necessarily
excreted again from it, because it is not unnatural to the
blood. To ascertain whether Iron given in small quantities
is excreted by the kidneys, I have tested the urine of a patient
who had been for some time taking thirty drops of the
Tincture of the Sesquichloride twice a day: but I was unable
to detect in it any trace of the metal.
But when given in large doses, Iron passes off by the urine
and by other secretions. Some portion may be excreted by
the mucous membrane of the intestines, and combine in the
cavity of the bowel with Sulphuretted Hydrogen. The resulting
Sulphuret communicates to the fæces a characteristic
black colour. The cause of this colour was ill understood;
until pointed out by Berzelius.
When the salts of Iron pass through the glands, they generally
prove to be more or less astringent. The Chloride and
Sulphate are most so; and they will thus be mentioned again
under the head of Astringent medicines. The tincture of the
Sesquichloride has obtained the reputation of being diuretic.
But this constitutes no exception to the rule of its being
astringent; for this diuretic power is owing to a peculiar
ether, formed with the spirit by an excess of hydrochloric
acid used in the preparation of the tincture.
I believe Iron to be simply and solely a Restorative remedy.
By improving the condition of the blood, it appears similar in
action to Tonics; but it is not a true Tonic, for neither in debility
nor in Ague is it of any service, unless there is at the
same time Anæmia. In some cases, even of Anæmia, Iron
will not effect a cure. This must be because the appropriative
power of the system is so weakened and degenerated, that
it is incapable of consigning even this needful substance to
its proper destination.
Anæmia is the one disease in which Iron is of use. Purgative
medicines form a valuable adjunct to the treatment in
most cases. Dr. G. Owen Rees has suggested that they may
be of use by removing some of the water of the blood, so that
the corpuscles, being then shrivelled by exosmosis of their
contents, may be in a fitter condition to absorb the "ferriferous
chyle." And yet, if so, the drinking of a single glass
of water would probably be sufficient to swell out the corpuscles
again, and thus put a stop to the process. It is just possible
that a Cathartic may be serviceable by purging away
from the blood some effete matters, as Sulphuretted Hydrogen,
formed by the continual decomposition of the tissues,
which would have hindered the operation of the Chalybeate
in the blood, by decomposing it.
The use of Iron may, I think, be summed up by saying that
it cures Anæmia. In this way it may benefit, and sometimes
cure, other disorders, in which Anæmia is apt to be a prominent
symptom. Such are Amenorrhœa, Scrofula, Cancer,
chronic Ague, Hysteria, Chorea, and Bright's disease of the
kidney. But it seems that it can never be used advantageously
in these disorders, when they are unattended with
Anæmia; nor even then is it to be preferred to the other
remedies specially appropriate in each case, but ought rather
to be conjoined with them. Cancer, and granular kidney
disease, may perhaps be alleviated, but are seldom cured. In
Chorea, Arsenic or Quinine may be used, with or without
Iron. Aloetic purgatives may be advantageously conjoined
with Chalybeates in Amenorrhœa and Hysteria. Their use
may be accompanied by cold affusions, or by some antispasmodic
stimulant. In Scrofula the Iodide of Iron affords us
a valuable double remedy. In chronic cases of Ague, when
accompanied with Anæmia, as is often the case, Iron may be
prescribed with advantage.
In general Anæmia, an occasional purge, a generous diet,
with good air and exercise should be combined, if possible,
with the Chalybeate treatment.
Ord. VI. Solvents.
(Antilithics.
The mineral Alkalies, their Carbonates, and neutral salts
with vegetable acids. Biborate and Phosphate of Soda.
Benzoic and Cinnamic acids.
Antiphosphatics.
Mineral and vegetable acids. Sour fruits.)
Of all the fluid secretions, the secretion of Urine is perhaps
the only important one which cannot cease to be fluid without
immediate damage to the system. The deposit of solid matter
from this secretion is dangerous, because tending to the
formation of a solid calculus in the kidney or the bladder, in
neither case easily extracted, and acting like a foreign body
in these sensitive organs. This urine, naturally clear and
limpid, contains in it several substances which are by their
nature insoluble, but are held in solution by certain other
materials. But in some morbid states these latter materials
may be wanting, or else the insoluble bodies may be secreted
in such quantity that the solvent material is unable to hold
them in solution. In such instances, these parts of the urine
may either be separated by the kidneys from the blood in a
solid state, or may be deposited from the urine after excretion
or on cooling. They then fall down in a crystalline or
finely divided state, and constitute Urinary Deposits.
Solvents are medicines which are employed to hold these
insoluble substances in solution, where there is not enough of
the natural solvent material in the system. They are medicines
which tend, after being absorbed, to pass out of the
blood into the urine. Although we are ill-informed as to the
nature of the ordinary urinary solvents, yet it is evident that
they must be present, because substances which are by their
nature insoluble occur in healthy urine. And it is also evident
that these medicines are able to supply their place; for,
after one is given in a case of urinary deposit, this latter disappears,
at the same time that the solvent remedy may be
detected chemically in the urine.
In this, the last order of Restorative Hæmatics, a number
of apparently dissimilar medicines are grouped together, all
of which agree in this point of their action.
The deposits in which solvents are appropriate are termed
respectively Lithic and Phosphatic. Among the first are comprehended
Uric acid (also called Lithic,) Urate of Ammonia,
and the more rarely occurring Urate of Soda. In the second
set are comprised the Triple Phosphate of Ammonia and
Magnesia, and the Phosphate of Lime. These deposits are
each known by their peculiar form under the microscope.[35]
They may easily be separated from the urine, when in any
amount, and tested chemically. The Lithic deposits, (i.e.
Uric acid and Urate of Ammonia,) are entirely dispelled by a
red heat, and are soluble in alkalies. The Phosphatic deposits
leave an earthy residue when heated, and are soluble in acids.
When thus held in solution, the former are precipitated by an
acid, the latter by an alkali, because by such a reagent that
solvent is neutralized in each case.
Now the circumstances which may cause these deposits are
mainly of four kinds. (1.) A wrong in the diet. (2.) An
error in the normal reaction of the blood, causing these matters
to be deposited, without being themselves in excess. (3.)
The suppression of another secretion. (4.) A fault of some
process of assimilation or secretion, causing an absolute excess
of these constituents of the urine.
Urinary sediments may be caused by slight variations in
diet. Excessive indulgence in animal food or in wine may
cause an over-secretion of Lithic acid. Sour drinks may cause
a similar deposit, by rendering the urine acid; and sweet
fruits, containing vegetable salts of the alkalies, may produce
a phosphatic sediment, by rendering it alkaline. Such cases
may be remedied by an attention to diet.
Again, deposits may be caused by an excess of acid or
of alkali in the blood, which excess is excreted by the kidneys,
and causes a lithic or phosphatic gravel, without an excess
of Lithates or of Phosphates in the urine. Whatever be
the condition of Uric acid in urine, it is certain that it is
held in solution by some matter of an alkaline nature.[36]
When this alkaline matter is neutralized by an acid, the
Uric acid precipitates. This may perhaps be caused in Rheumatic
fever by an excess of Lactic acid. The Phosphates are
held in solution by Phosphoric acid, or by that matter which
gives to healthy urine its slight acid reaction.[37] An excess of
alkali in the blood, which may probably occur in Typhoid
and low fevers, will cause their precipitation. Or the alkali
may be formed in the bladder by the decomposition of the
urine. This may occur in inflammation of the bladder; or in
retention of urine caused by paraplegic paralysis.
In such cases there is no absolute excess of the deposited
matter; but it is in relative excess, for the substance which
should properly dissolve it is neutralized by a reagent of an
opposite nature. Acids and alkalies have already been mentioned
as efficacious in these instances; the former in phosphatic,
the latter in lithic deposits. They directly neutralize
the disturbing cause; the alkali, or the acid. They are not
in such cases truly solvents; they do not themselves hold in
solution the insoluble material, but they set free something
else that shall be capable of doing so. (Vide Acids; Alkalies.)
A suppression of the secretion of the skin causes a lithic
deposit in some cases, as in a common "cold." For the perspiration
contains a free acid, probably lactic or butyric; and
when it is suppressed, the secretion of this acid is thrown
upon the kidneys, and the urine is rendered more acid than
naturally. The obvious indication in the treatment is to restore
the function of the skin, as by warm baths, diaphoretics,
etc.
It is in the case of urinary deposits produced in the fourth
way that true solvents are appropriate.
From some morbid condition of the system, it happens that
these insoluble constituents of the urine are secreted in absolute
excess,—in a larger quantity than in health. Now the
system labours to excrete them in solution, even when in excess;
and often succeeds in doing so. But frequently this
cannot be done, it being impossible for a sufficient quantity
of the solvent material to be formed out of the blood. There
is then a deposit in the urine.
We have seen that when such matters are deposited because
in relative excess, the only fit mode of treatment consists in
the administration of an acid or an alkali, which shall neutralize
the morbid reaction of the blood. Such a case is rare;
but these cases of absolute excess are much more common.
There are two ways in which we may treat them; we may
adopt either curative or palliative remedies. We may aim at
the cause of the disease, which is generally in the blood. An
absolute excess of Lithates may be caused by dyspepsia, or by
a gouty disorder. This is most surely controlled by a Catalytic
medicine. (Vide Antiarthritics.) An absolute excess of
Phosphates may be caused by an organic derangement of the
nervous centres, when it is very difficult to cure; or it may
simply be due to great nervous excitement, hard study, or
melancholia. Such cases should be distinguished from a mere
alkaline condition of the urine, without absolute excess of
Phosphates, and may often be cured by attention to the
disturbed nervous functions.
Such a curative course of treatment aims at the primary
cause of the deposit; but when we are unsuccessful in our
attempt to control this, or when the excess of solid matter is
so great as to be positively dangerous, we are then driven to
have recourse to palliative remedies. These are Solvents;
medicines which pass into the blood, combine there with the
peccant matters, pass out with them into the urinary secretion,
and hold them there securely in solution. Such an agent
may often be advantageously combined with the Catalytic
remedy, which tends to cure the systemic disorder. It is a
blood-medicine. Its action is so far permanent, that it effects
its object definitely, dissolving and carrying away a certain
portion of insoluble matter. But as it also passes out itself,
it requires to be frequently repeated, because the deposit continues
to be formed, and requires each time a fresh portion of
solvent. It obviously acts on the Restorative principle. The
deposit should be excreted in a dissolved state, but is not.
The remedy therefore supplies a want.
Water is the simplest and most efficacious of all solvents,
and should in all cases of gravel be very freely administered.
Bouchardat has remarked that great water-drinkers are never
afflicted with stone. All the urinary deposits are, to some
extent, soluble in water, although comparatively insoluble.
Whenever the urine is of higher specific gravity than it should
be in health, more water should be drunk. The average specific
gravity of healthy urine is about 1.018.[38]
Acids and Alkalies are most important as solvents. They
do not now act indirectly, as in the case before mentioned, but
directly dissolve the insoluble matter. Acids dissolve a phosphatic,
and Alkalies or their carbonates a lithic deposit, in
the body, as well as out of it. Although the natural solvent
may be neither an acid nor an alkali, but something else different
in nature from these, yet any thing that will rightly dissolve
the deposit will be fit to supply its place. Any of the
free Acids may serve to dissolve a precipitated phosphate.
Hydrochloric is perhaps the best of the mineral acids, although
Phosphoric has been recommended on theoretical
grounds. Sulphuric is the least efficacious because it does not
always pass out in the urine. (Vide Chap. IV.) Sour fruits,
as Currants or green Gooseberries, may be useful in phosphatic
cases; but ripe fruits have an opposite tendency.
Acidulous drinks may be recommended, as Cider, Perry, and
Rhenish wines. Of the free alkalies used to dissolve a lithic
sediment, Potash is preferable to Soda, because it forms a
more soluble compound with Uric acid. The Bicarbonates of
the fixed alkalies are best, because least irritant. Bicarbonate
of Soda is contained in Vichy water. The soluble Bicarbonate
of Magnesia may be given with advantage. The Carbonate of
Lithia has been recommended by Mr. A. Ure; but it is comparatively
insoluble. The neutral vegetable salts of the alkalies,
and sweet fruits which contain them, are equivalent to
the Carbonates, because converted into them in the system,
as has already been shown. They may be pleasantly administered
in the form of effervescing draughts, in the formation
of which the Carbonic acid of an alkaline carbonate is displaced
by Citric or Tartaric acid.
The danger which attends the continual use of acids, or of
alkalies, particularly of the latter, is that their long employment
may engender a condition of an opposite nature to that
which they were intended to alleviate. An acid may at length
cause a lithic deposit in the urine; or, still more frequently,
an alkali may produce a phosphatic sediment. Their administration
should therefore be conducted with caution.
There are some other remedies which may be advantageously
employed as solvents for Uric acid and Urates, whose
use is not attended with this danger, and whose efficacy is a
proof that the occurrence of a deposit in the urine is not a
mere question of the preponderance of acid or of alkali in
that secretion. The most important of these is the common
Phosphate of Soda, first recommended by Liebig,
who discovered that Uric acid was soluble in a solution of
that salt.
If forty grains of dry Phosphate of Soda, seven grains of
Uric acid, and fifteen of Hippuric acid, be dissolved in a pint
of hot water, and to this solution two per cent. of Urea be
added, a kind of artificial urine will be formed.
Biborate of Soda, or Borax, has also the power of dissolving
Uric acid, and has been recommended in the treatment of
lithic deposits by Bouchardat and Binswanger.
Mr. A. Ure has strongly recommended Benzoic acid in
these cases. It passes out in the urine as Hippuric acid. (Vide
Prop. VI.) The amount of the deposit appears to decrease
under the use of this remedy, but whether the formation of
the Uric acid in the blood is prevented, as supposed by Mr.
Ure, or whether it is not simply held in solution by means of
the Hippuric acid, is not clear. Dr. Golding Bird recommends
also Cinnamic acid, which is contained in Cinnamon
water, and in the balsams of Peru and Tolu. It resembles
Benzoic, and undergoes the same change into Hippuric acid.
The salts of these acids possess a similar power.
Diuretics in general are useful in all cases of urinary deposit,
for they increase the quantity of the fluid part of the
urine. It is observed by Dr. Prout that healthy urine is the
best solvent that we are able to supply.
When solvent remedies are employed for the purposes above
mentioned, they not unfrequently fail altogether; and, as has
been already observed, they require, even when successful, to
be perpetually administered, or else the deposit will recur.
For the solvent passes out along with each successive quantity
of the Lithic or Phosphatic matter that is formed and excreted.
A radical cure of such deposits can only be effected by a
medicine that shall counteract the morbid process by which
they are continually produced. This cannot be done by a
Restorative, but requires a Catalytic medicine. Such remedies
we must presently consider. (Vide Antiarthritics.)
Thus are concluded the six orders of restorative medicines;
all of which are seen to agree together in some common characters.
When a disease depends on a want of some material in the
system, then it admits of being cured by a restorative, which,
in the theory of its action, is the simplest of all known medicines.
And when a morbid process results in a diminution of
the amount in the blood of some necessary constituent, then
also may a Restorative be of use in alleviating the consequences
of such a disorder; or may even effect a cure, when
the morbid process has ceased, and left only its results behind
it.
But when the materies morbi is still working in the blood,
a radical cure can only be effected by a Catalytic medicine,
which shall be capable of meeting it there, and of counteracting
its noxious influence.
Some Restoratives are also included among Catalytics, from
a regard to a different phase of their action. The most important
of these are Alkalies, which are of use in general inflammation,
and also in Scrofulous and Scorbutic diseases,
acting in a way that is at present but obscurely explained.
When the modus operandi of a medicine is obscure, but
when it is apparent that it has the power of counteracting a
disease, I have preferred to place it among Catalytics, rather
than to include it with Restorative medicines. But there are
not many cases in which we are thus left in doubt.
The diseases curable by Catalytics are all evidently produced
by an active morbid agency. Those which are treated
by Restoratives are just as evidently remediable by the artificial
supply or substitution of some one or more of the elements
of the blood.
These constitute the second division of Hæmatic medicines.
The above name is applied to them on the assumption that
their operation in the blood results in the destruction or counteraction
of certain morbid agencies. (καταλυω.)
The differences in action between this and the preceding
division of blood-medicines have been stated at length in the
remarks on Hæmatics in general. On recurring to Prop.
VII., it will be seen that it is there stated—
"That others, (medicines of the first class,) called Catalytics,
act so as to counteract a morbid material or process,
and must pass out of the body."
The action of the remedies in this division, which are the
surest and most potent of all those that are employed in the
treatment of disease, is involved in a greater degree of doubt
and obscurity than that of any other class. Though there
may be in some cases a certain dim explanation which we
may catch hold of, and strive to fix or to render definite, yet
in many instances there is not even so much as this. How
can we, for example, by any of the common terms which are
made use of to designate the actions of Mercury, of Arsenic,
and of Iodine, express the peculiarity of their influence over
Syphilis, Lepra, and Scrofula, respectively? Does it not
seem better to confess our ignorance, and to say that all we
know for certain is that these remedies have the power of
antagonizing certain diseases?
Having done this, we may afterwards try, if we can, to
invent for this action a theoretical explanation. Our arguments
and theories will not affect the fact, nor will they lead
us into danger, if we have first laid down the truth, however
incomprehensible, as the only secure foundation, in such a
manner that it shall be incapable of being disturbed by the
flimsy superstructure. Some philosophers have erred in this;
that they have first, with much pains and labour, erected an
airy fabric on a basis of incontestable truth,—but subsequently,
relying too much on that which they have themselves
raised, they have commenced to pull up the blocks on which
it was founded, and have thus brought the whole speculation
tumbling to the ground in ruins.
Considering then that the action of Catalytic medicines in
each disorder is of a special and peculiar kind, which I think
will not be denied, I have grouped them in orders which are
named according to the several morbid states in which they
are employed.
| Catalytica. |
|
| Ord. 1. Antiphlogistica. |
| Ord. 2. Antisyphilitica. |
| Ord. 3. Antiscrofulosa. |
| Ord. 4. Antiarthritica. |
| Ord. 5. Antiscorbutica. |
| Ord. 6. Antiperiodica. |
| Ord. 7. Anticonvulsiva. |
| Ord. 8. Antisquamosa. |
The medicines of the first order are employed in inflammatory
disorders generally, and possess an influence over the
process of sthenic inflammation, however first produced. The
second order contains those that are used in the several forms
of Syphilis. The third, those that are employed in Scrofula.
The fourth, those that are found to be useful in the cure of
painful affections of the joints, as Gout and Rheumatism; and
also of Oxaluria, Lithiasis, Diabetes, and other disorders of
secondary assimilation. The fifth order contains those that
are useful in Scurvy. The sixth, those that are employed in
Ague, Remittents, and other periodic disorders, on the Catalytic
principle. The seventh, those used in convulsive disorders.
Lastly, the eighth, those that are capable of curing
Lepra, Psoriasis vulgaris, and some other skin diseases.
The action of these medicines being much more obscure
than that of Restoratives, I shall therefore have less to say
about them individually, and shall not go so much into particulars.
That part of Prop. VII. which refers to Catalytics,
may be divided into the following minor propositions:—
m. p. 1.—That they act in the blood, and that their effect is
permanent.
m. p. 2.—That each of itself tends to work out a peculiar operation in the blood.
m. p. 3.—That the diseases in which they are used depend on
certain morbid materials or actions in the blood.
m. p. 4.—That the result of the action of a Catalytic medicine is in some way to
neutralize or counteract some one or more of these morbid processes.
m. p. 5.—That these medicines are all unnatural to the blood,
and must at length pass out of the system.
It might seem at first as if the first, fourth and fifth of these
minor propositions would alone suffice to include the original
affirmation. But a medicine may act in the blood, and may
counteract a disorder; and yet it may counteract the disorder
in some other way than by acting in the blood. It is necessary
further to prove the disease to be a blood disease. And
the evidence of counteraction will be rendered stronger if we
can prove that the medicine employed is itself capable of setting
up in the blood some peculiar process—of causing in it
a change of some special kind. For, were it not to do so, we
could hardly understand how it could meet the requirements
of one case more than of another, or how it could at all arrest
an active process in that fluid over which it exerted itself no
particular influence. And this thing, which is laid down in
the second minor proposition, can, I think, be proved in the
great majority of instances.
The following is the arrangement of the subject which I
have thought it best to adopt. We will, in the first place,
consider some of the statements ventured by authors respecting
this kind of medicines: as a comparison of these should
aid us in the discovery of the truth. In the second place, it
will be convenient to enumerate the medicines contained in
the orders named above, and to proceed to prove the minor
propositions of Catalytics taken altogether. A considerable
amount of difficulty attaches to this consideration; and, as the
argument which applies to one order will apply to all, much
unnecessary repetition will be avoided by this plan. In the
third place I must conclude by making some remarks on each
of the orders in succession. To proceed now to the first of
these topics.
In referring to the opinions that have been advanced on the
action of this group of medicines, our task is rendered comparatively
easy by the fact that a great number of writers on
Materia Medica have failed to recognise them collectively. It
may seem strange to one who has reflected on the subject, but
it is nevertheless true, that the majority of authors have taken
no notice whatever of medicines acting in the blood, with the
exception of Acids and Alkalies, which are grouped by some
as chemical remedies. All other medicines have been generally
arranged under the two great and ill-defined heads of Nerve-medicines
and Eliminatives. I cannot find it possible, by either
of these terms, to give any idea of the real action of the many
important agents which I have included in this division.
It would seem that it has been generally supposed that medicines,—bodies
of active properties, and more or less peculiar
construction,—are able to enter and to pass through a fluid
which is still more complicated and changeable in nature than
themselves, yet that while so doing they produce no impression
upon it, but proceed passively to the solid tissues, or
quietly pass out of the body, without ever leaving behind
them any trace of their action.
Certain writers have made some amends by including in
their arrangements a class termed Alteratives. But even
then they have not unfrequently laid it down as a rule that
they produce, in the first place, an impression on the nervous
system, and that this has subsequently the effect of altering
the manifestations of vital force. How varied and peculiar in
nature must these nervous impressions be, to account for actions
which are often so widely different!
The medicines thus grouped as Alteratives correspond very
nearly with my division of Catalytics. The permanency of
their effects, and the fact that the disorders which they cure
are blood-disorders, will sufficiently stamp the character of
the operation of these remedies.
In many works, as in those of Dr. Duncan, of Dr. A. T.
Thomson, and more lately, of Drs. Ballard and Garrod, the
existence of a class of Alteratives or blood-medicines is not
even recognised or alluded to.
But in the learned classification of Dr. Pereira blood-medicines
hold an important place. All except Chalybeates are
grouped together in a sub-class, called Spanæmics, because
they tend to impoverish the blood. In addition to those
which I have named Catalytics, there are here the acids and
alkalies. It is true that all these medicines, after long use,
impoverish the blood, which, indeed, suffices to prove my first
point, viz,: that they act in the blood, and that their effect is
permanent. But Dr. Pereira has founded his classification on
the physiological action of medicines, and not on their therapeutical
uses, which form the basis of mine. Thus he takes
no notice of the questions of what their ultimate destination
may be, or what their primary modus operandi, whether they
have to remain in the blood, or to pass out of it, and whether
they can act by supplying a material to it, or by neutralizing
a material in it. The subsequent statements which Dr. Pereira
has chosen as the basis of his subdivisions, founded often on
therapeutical action, seem in certain cases to be somewhat
problematical. Thus he calls Acids "adipsa," or thirst-quenching,
which very imperfectly expresses their action.
Alkalies are grouped with Salts, Iodine, and Sulphur, under
the general title of "resolventia seu liquefacientia," i.e. resolvents,
or liquefacients, which involves an assumption that
some might be inclined to dispute. The title of Spanæmics,
applied to the whole, though unobjectionable in a classification
which is founded upon their ultimate action in health, would
be quite inappropriate in an arrangement like mine, which has
to do with their influence in the cure of diseases. For our
object in making use of such agents is not to impoverish the
blood, but to obtain such a manifestation of their power as
shall suffice to neutralize the noxious agent, and no more.
Dr. A. Billing (Principles of Medicine, 5th edit. pp. 70-75)
considers that Mercury, Arsenic, Colchicum, and all the medicines
which have been called Specifics, are not in fact so,
but that they are capable of subduing different kinds of inflammation
by causing contraction of the dilated capillary
vessels. This explanation has certainly the charm of simplicity,
but not, in my opinion, the merit of truth. Dr. Billing
supports his argument by instancing the number of remedies
that have been used in Syphilis, and considers that they
must all operate in a similar way, both in this and in other
disorders. Yet are all these medicines of use or advantage in
Ague, in Lepra, in Chorea, and in Scrofula? But why is it
not so, if all act in the same way? Their several actions
should exhibit no difference in kind, but only in degree. It
is the opinion of the same able authority that Mercury and
Iodine diminish morbid growths by starving them; that they
cut off the supply of blood by contracting the capillaries in
the same way as in other cases. But why then can we not
thus remove a fatty tumour, a true exostosis, or a malignant
growth? We are seldom able by such means to reduce the
size of a tumour, unless it depends on a blood-disorder, as
Syphilis or Scrofula. The wide distinctions and the shades
of difference which exist between the operations of these several
medicines are surely too many and too serious to allow us
to account for them all by one explanation.
But we may put aside general arguments, and appeal to
facts. In the first place, it is very far from being proved that
in all these disorders the capillary vessels are dilated. But
let us even admit that it is so proved, and we are not then
nearer to the establishment of the above hypothesis. For is
the action of any medicinal agent on the capillaries constant
in character?
Mr. Wharton Jones, in his Astley Cooper Prize Essay,
states that he has found the effects of medicinal solutions on
the capillaries in the web of a frog's foot to be very various.
For even a solution of Sulphate of Copper has been known to
cause dilatation, and one of Atropia to produce constriction;
though the former is an astringent; and the latter a paralyzer.
So that the vessels are not nearly so much under the influence
of such agencies as Dr. Billing would seem to imagine. In
these experiments the solutions were concentrated, and applied
directly. But in the cases in point we might have two
or three grains of Iodide of Potassium, one-tenth of a grain of
Arsenite of Potash, or one-twentieth of a grain of Bichloride of
Mercury, diluted down by about twenty pounds of blood, and
extended through many miles of capillary tubes! And if
simple contraction of the capillaries were required, surely
Astringents, which are known to effect this, should be the
most useful of all these medicines. But we do not find it to
be so. Further, this idea must include a virtual denial of the
causation of blood disorders by special morbid agencies.
Such are the grounds upon which is founded a denial of the
existence of specific medicines—i.e. of remedies which are of
particular or special use in one or more disorders. Is it reasonable
to deny that Mercury is of particular use in Syphilis?
that Iodide of Potassium exerts a special influence over secondary
forms of the same malady? that Iodine and Potash
are each peculiarly adapted to scrofulous cases? or that Colchicum
will often stop a fit of the Gout when other medicines
have failed to relieve it? If we cannot deny it, we must
admit such actions to be in some degree specific. To adopt
this term is to a certain extent to confess our ignorance, and
for this reason many have objected to it; but this we cannot
avoid. The word is, however, decidedly objectionable, when
it is misapplied to express the idea of some particular medicine
being the only one that can be used in a certain disorder.
For this is an exaggeration of the truth that may lead to very
serious error.
Before now proceeding to the proof of the minor propositions
of Catalytics taken collectively, I must enumerate the
chief remedies which I intend to include in the eight separate
orders into which this division of blood-medicines has been
divided.
Ord. 1. Antiphlogistics.
Antimonials; Mercurials; Alkalies; Salines.
Ord. 2. Antisyphilitics.
Mercurials; Preparations of Gold; Iodide of Potassium;
Sarsaparilla (?).
Ord. 3. Antiscrofulitics.
Iodine; Bromine; Chlorine; Iodides and Bromides;
Potash.
Ord. 4. Antiarthritics.
Colchicum; Nitro-hydrochloric Acid; Lemon-juice.
Ord. 5. Antiscorbutics.
Citric Acid; Lemon-juice; Fresh Vegetables;
Salts of Potash (?).
Ord. 6. Antiperiodics.
Arsenious Acid; Arsenite of Potash; Alum;
Chloride of Sodium.
Ord. 7. Anticonvulsives.
Preparations of Arsenic, Silver, Zinc, Lead,
and Copper.
Ord. 8. Antisquamics.
Preparations of Arsenic; Sulphur; Pitch.
Under each head I have given the most important of those
medicines which I conceive to act on the Catalytic principle.
Other medicines may cure some of these disorders, or at least
alleviate them; either by acting as Restoratives, as in the case
of arthritic and of periodic disorders; or by influencing the
nervous system, which plan may be effectual in some convulsive
affections.
The prefix Anti- involves a principle. These medicines
produce certain actions which are contrary to diseased actions,
inasmuch as they neutralize them, and cannot subsist
with them. It is granted that in some cases the actions
may appear similar in some respects. But this merely shows
that they move, as it were, in the same sphere, for else one
of them could not meet the other. However the operation
of a medicine may sometimes seem to resemble that of a
disease, it is always in effect contrary to it. The similarity is
of a kind which does not concern us. An acid and an alkali
are so far similar, that they may both produce heat when
mixed with water, and both prove corrosive and destructive to
organized tissues; but they are practically contrary, and when
brought together they neutralize each other. Let us now
proceed to the minor propositions.
Catalytic medicines act in the blood, and their effect is permanent.
This is simply to affirm that they belong to the class
of Hæmatics, to which Restoratives also belong. Of all that
I have named, there are not any, except Colchicum and Antimony,
that possess in any degree the action of nerve-medicines—i.e.
that exert a sudden and transient influence over
the nervous system. I believe the sedative powers of these
medicines to be quite distinct from their Catalytic influence.
In the proof of the second minor proposition, I shall attempt
to show that each of these remedies has a peculiar action of
its own on the blood, even in health; which cannot be said of
Restorative medicines. Of all these Catalytics two things
are known. When they cure a disease, they do so definitely,
so that it does not in general tend to return; and when they
only alleviate it, the improvement effected is more or less permanent.
In the second place, they are found to produce,
after being long administered, a change for the worse in the
blood, a diminution in the amount of Fibrine and of the red
corpuscles. Thus they are blood-impoverishers, when given
in excess. These considerations alone, when combined with
the proof of absorption—i.e. that they all pass into the secretions,
and may be detected there—are conclusive as to the fact
of their being Hæmatic medicines. We pass on now to the
third proposition, which consists in the statement of a property
that is peculiar to Catalytic Hæmatics.
Each Catalytic tends of itself to work out a peculiar operation
in the blood.
This peculiar process, established by their presence in the
blood, forms part of the known history of each Catalytic
medicine. It will suffice to demonstrate this if I condense
into as few words as possible the facts that are known on this
subject, with respect to each of the orders of this division of
remedies.
Of Antiphlogistic medicines, some possess a power which
stamps them at once as likely to be useful in the treatment
of inflammatory disorders.
Alkalies are known to have the chemical property of holding
Fibrine in solution. By exerting this power in the blood,
it seems that they may prevent its abnormal deposition or
coagulation in inflammatory cases, and at length diminish it
in quantity. On this principle they were proposed and used
successfully by Mascagni in acute inflammations. Their
efficacy in retarding the formation of crude deposits in scrofulous
and tubercular diseases may possibly be assigned to
the same operation. Potash has been extolled by Dr.
Theophilus Thompson as a powerful preservative for those
who are predisposed to phthisical disease. Alkalies in small
doses, and in cases requiring them, may be Restoratives.
Salines have been shown by Mr. Gulliver to have the effect
of keeping the blood-corpuscles apart from one another. This
may partly explain their action; for in inflammatory blood
the corpuscles display a peculiar and abnormal tendency to
aggregate together in rows. Salines also are solvents of
Fibrine.
The immediate action of Mercury in checking inflammation
is often very apparent in the case of Iritis. This medicine
in some way diminishes the plasticity of the Fibrine of
the blood; and probably promotes absorption by preventing
in this way a further deposit of lymph. If the blood be
analyzed after the continued use of Mercury, it is found to
contain less Fibrine than in health. It has also a peculiar
action of its own in the blood, for it sometimes produces
various eruptions, particularly Eczema, as well as a state
called Mercurial fever.
Antimony has various and marked medicinal properties:
in large doses Neurotic; in all cases Eliminative. But we
are now concerned merely with an agency in the blood. It
has certainly some action of this kind. When rubbed on the
skin it produces a pustular eruption; and M. Lepelletier gives
a case in which it did this when administered only internally.
Magendie found that when given to dogs it produced engorgement,
and often inflammation of the lungs. Antimony
seems to exert a blood-influence over inflammation somewhat
similar to that of Mercury; but it further adds to this a
powerful sedative effect. Antimony generally arrests inflammation
by reducing the pulse; but Mercury reduces the pulse
by arresting inflammation.
Thus do Antiphlogistics exert that operation in the blood
which is essential to Catalytic medicines. The divisions of
Hæmatics differ in this: Restoratives act by being in the blood;
Catalytics by working in the blood. All we have to prove of
the latter just now is to establish this part of their action.
Antisyphilitics have also this action. Mention has already
been made of the hæmatic effects of Mercurials. The action
of the compounds of Gold is similar, though these are not
now often employed. But as far back as the commencement
of the eighteenth century the administration of Gold in syphilis
was strongly recommended by Dr. A. Pitcairn. He
employed the pure metal in a fine state of division. He also
made use of a mercurial which resembled our modern blue-pill,
but must have been considerably less potent, for it was
given in drachm doses.
Iodide of Potassium may be said to combine the actions of
Iodine and of Potash. This medicine is very active in causing
the absorption of syphilitic nodes. Its use is sometimes followed
by a slight cutaneous eruption.
Sarsaparilla is supposed by many to exert an alterative
action in the blood; but this is not very clear, nor is its
utility often very decided.
Antiscrofulitics form the third order. Iodine and its compounds
have certainly an action on the blood. When given
in excess, or for a long time, they may cause a train of symptoms
to which the collective name of Iodism has been applied.
The most prominent are—coryza, itching, watering of the
eyes, fever, and great constitutional depression. It powerfully
promotes absorption in certain cases. Its special actions
will be subsequently described in the remarks made on
the second and third orders of Catalytic medicines.
Potash has been already considered. Bromine and free
Chlorine are very analogous to Iodine in their operation.
Antiarthritics exert an influence on the blood. This is
least apparent in the case of Colchicum, which is a somewhat
mysterious remedy. But it has been said by some to increase
the amount of Urea in the urine; by others, to promote the
excretion of Uric acid. (Vide Antiarthritics, and Chap. IV.)
Nitro-hydrochloric acid contains Chlorine, which is an oxidizing
agent, and probably exerts in the blood an action of
this kind. It is clear that it is capable of retarding the
formation in the system, and deposit in the urine, of lithic
acid and oxalate of lime; though its modus operandi is not
determined with certainty. This question is of some theoretical
importance, and will soon be considered at some
length.
Among Antiscorbutics, Potash and its salts have been already
shown to affect the blood. Their efficacy in scurvy is,
however, a disputed point. That of Lemon-juice is established.
It contains Citric acid and Potash; the former in
great excess. Now either of these by itself would, in cases
requiring it, and given in small doses, act as a Restorative.
In large doses, Citric acid would disturb the reaction of the
secretions, and Potash would impoverish the blood. When
both together, the Citrate of Potash would undergo oxidation,
and thus exert an operation in the blood of a refrigerant
kind. Similar materials occur in most fresh vegetables.
Antiperiodics are medicines which are used in the cure of
Ague, and of other periodic diseases, on the Catalytic principle.
Tonics are used in the same diseases on the Restorative
plan; but their utility extends also to other cases on
the same grounds. Arsenic is the most potent of Antiperiodics.
The Terchloride, and the Arsenite of Potash, are
the preparations most frequently employed. Arsenic produces
an evident action in the blood. When given in slight excess,
it is apt to bring on œdema of the face, and redness of the
conjunctivæ. Besides causing various nervous disorders when
in large doses, its continued use may bring on a cutaneous
eruption, described by Mr. Hunt as a kind of pityriasis, together
with a failure of appetite, general depression, a quick
small pulse, hurried respiration, and sometimes swelling of the
feet. Any kind of eruption would alone constitute sufficient
proof of an operation in the blood.
The metallic salts used as Anticonvulsives are all capable,
when taken for some time, of causing a deterioration of the
blood. This is most apparent in the case of Lead, which,
besides a number of nervous symptoms, tends to bring on a
kind of jaundice, with general wasting of the body. Chronic
poisoning by Zinc and Copper resembles that by Lead. The
symptoms of what is called "Zincal intoxication" were
recently described to the French Academy by M. Landouzy
of Rheims, as occurring constantly among the zinc-workers.
There was sometimes an œdema like that produced by
Arsenic.
The production of all the known nervous disorders by the
presence in the blood of different metallic medicines, gives
a strong additional probability to the belief that these disorders,
when occurring spontaneously, are in many cases due
to the presence in the blood of some unknown poison.
Among Antisquamics, the last Catalytic order, we meet
with Arsenic again. Common Pitch is of almost equal utility
in Lepra. It has some action in the blood, due to some one
of its bituminous principles; but this action is not well made
out, or understood. Sulphur, besides its use externally in
Scabies, is administered internally with advantage both in
this and some other skin diseases. It effects changes in the
blood, inasmuch as it is found to combine there both with
hydrogen and oxygen, and to carry them out of the system
as sulphuretted hydrogen and sulphuric acid. Dr. Pereira
and others ascribe to Sulphur a resolvent and liquefacient
action.
Thus it is sufficiently shown that all of these medicines work
out a certain process or operation in the blood, and affect the
condition of that fluid. But I am very far from believing
that this known operation is in all cases the one by which
they neutralize morbid poisons. This action is probably of
a much more inscrutable character.
Before proceeding further, I may here take the opportunity
of insisting again on the differences between Catalytic and
Restorative medicines. Catalytics will even in health work
out their peculiar process in the blood. Restoratives exercise
in that case no particular influence. The latter may remain
in the blood; their office is supply or substitution. Catalytics
may not remain beyond a certain time; their office is counteraction.
The system then labours to excrete them. Before
passing out of the body, one or two, as Colchicum, may act
on the nerves. In the moment of excretion, the majority act
as Eliminatives. But some, as the metals used as Anticonvulsives,
are astringent, and diminish secretion generally.
Mercury, Antimony, and Iodine, are among the most important
Eliminatives known. They act on all glands, but on
some more than on others. Antimony is also a special sedative
to the Vagus nerve, and as such exerts an important influence,
which enables it sometimes to cut short the process
of inflammation by depressing the action of the heart.
We now arrive at the third minor proposition.
The diseases in which these medicines are employed are
active blood-diseases.
This consideration need not detain us long, for in most
cases the correctness of the statement is universally admitted.
Inflammation may be produced by a variety of blood-poisons,
in each of which instances it partakes of a special
character. Thus there are the syphilitic, scrofulous, and
rheumatic inflammations. Simple inflammation may be
caused by the injury of any part or organ, external or internal.
It commences in the capillary vessels, and, if extensive,
affects the blood generally, and produces fever. The
blood then contains an excess of Fibrine, causing it, on
coagulation, to exhibit the "buffy coat." There are also
found in this, according to Mulder, some peculiar hyperoxides
of Proteine. The colourless corpuscles are in excess; and
among the red corpuscles is observed a peculiar tendency
to arrange themselves together in rows. This is doubtless
in some way connected with the morbid process going on in
the blood.
Syphilis is evidently traceable to a special poison. This is
recognised by the fact of its communication from one person
to another. In the system of the infected person, if left alone
and uncontrolled, it breeds and increases in quantity, works
out all the mischief that it is capable of effecting, and may
again be propagated to others, either by inoculation into the
blood, or by an equally direct transmission to a tainted offspring.
Scrofula is also a blood-disease. All its manifestations are
explainable on such a supposition. It is transmissible from
parent to child; and it holds good as a general rule that
hereditary diseases are seated in the blood. It is unaffected
by any of those medicines that act only on the nerves. It
produces a deterioration of the blood.
Arthritic disorders are always accompanied by a change in
the blood. In Diabetes grape-sugar is present there in large
quantities, and has to be excreted by the kidneys. Similarly,
in Oxaluria, oxalic acid is found there; in Lithiasis, lithic
acid in excess. In Rheumatic fever there are profuse sweats,
in which the natural acid of the perspiration is enormously
increased in quantity. It is stated by Berzelius to be lactic
acid. Either this, or some other acid like it, must be formed
in excess in the blood. In Gout we have sometimes a deposit
of urate of soda in the cellular tissue opposite the small joints.
The same salt has been occasionally found in the urine in
Gout. Lastly it has been detected in the blood in that disorder
by Dr. Garrod, and since him, by Dr. Bence Jones.
(Animal Chemistry, p. 29.) Thus, in all these disorders there
is a wrong in the blood.
Scorbutic diseases, i.e., Scurvy and Purpura, are characterized
by a general poorness of the blood, with a special deficiency
in the amount of Fibrine and of salts. There is a
general tendency to hæmorrhage and ulceration all over the
body. It has been observed that these diseases seldom occur
in persons who are accustomed to a natural and mixed diet.
Periodic disorders are known to be attributable to the
entrance into the blood of a peculiar aerial poison. The mild
malaria of England excites a comparatively tractable ague;
that of the Maremma and of the Pontine Marshes, in Italy,
brings on very fatal fevers; while the remittents that are due
to the exhalations from the ground on the West coast of
Africa, and in the West Indian Islands, are of a still more
virulent nature. Accurate observations have shown that they
are all caused by the exposure of the system to this poison,
and by its working in the blood.
With Convulsive disorders there is more difficulty. Although
these diseases are manifested either by a derangement of the
nervous system in general, or by a disturbance of the functions
of the brain or spinal cord in particular, yet they are
very rarely accompanied with an appreciable nervous lesion.
When this is the case, as in the instance of Tetanus, which
may arise from a mere irritation of the end of a nerve, they
are extremely intractable, and are not at all under the influence
of those blood-medicines which are useful in other cases.
Epilepsy, too, may sometimes be due to a bony spicula or
tumour in the brain, or to the irritation produced by intestinal
worms in children; but these direct nervous causes of
such convulsive disorders are to be considered as the exception,
and not the rule. For they are more often connected
with a diseased condition of the blood.
Epilepsy and Hysteria are frequently inherited. This supplies
us with one argument. They are also apt to be brought
on by various depressing causes which affect the system in
general. The strumous diathesis, which originates in the
fluids, and not in the nervous system, is affirmed by Dr.
Cheyne and Dr. Watson to be a powerful predisposing cause
of Epilepsy. Hysteria, too, is very often associated with
Anæmia. Tetanus even depends very much on certain atmospheric
conditions. There are sometimes, as it were, epidemics
of Tetanus, in which the slightest abrasion will suffice to
bring it on among the people residing in a particular neighbourhood.
It is often rife in one district a long consecutive
time. Facts like this must certainly be regarded as pointing
to a condition of the blood as one, at least, of the causes
of this terrible disorder. This condition of the blood may
react upon the nerves, and maintain in them a particular
morbid state. Chorea seems also to depend primarily on
the state of the blood, and is indirectly curable by medicines
which, like Iron and Quinine, improve its condition. In a
weakly and strumous child it may be brought on by a sudden
fright which would not affect one of a good constitution.
We might conclude from these facts alone that the blood is
often the seat and origin of these diseases. But there is yet
a stronger reason to induce us to suppose that they are frequently
produced by some poison in the blood, which acts
on and disturbs the nervous organs without perceptibly altering
their physical construction. Many medicinal substances
present us with an artificial illustration of this action. Lead,
Copper, Mercury, and Arsenic, by their presence and operation
in the blood, are capable of causing severe and chronic
nervous disorders, particularly Paralysis and Epilepsy. Many
of the vegetable Neurotics, after their passage into the blood,
bring about transient nervous symptoms which are identical
with those of disease. Thus Opium produces coma; Belladonna,
delirium; Aconite and Hemlock, paralysis; Hydrocyanic
acid, convulsions; Indian hemp, catalepsy. When the
cause of these affections is removed, the symptoms disappear;
when the cause returns, the symptoms return. The same is
apparently the case with those unknown animal poisons that
operate so as to produce nervous symptoms, without a nervous
lesion.
These convulsive disorders may be treated in either or both
of two ways. We may attack the supposed cause in the blood
by employing one of these mineral Anticonvulsives; or we
may simply apply our remedies to the nervous system, the
more immediate seat of the morbid manifestations, and adopt
a palliative or defensive course.
Skin diseases are no doubt connected with some disorder
in the blood. We might almost presume this from the analogy
of the known blood-poisons, by nearly all of which an
eruption may be produced. The eruptive fevers, which run
a certain course, depend upon contagious poisons; but they
are not under the influence of Antisquamic remedies. These
are serviceable in a class of disorders, of each of which a
cutaneous eruption is the most apparent, or the only obvious
symptom. The true squamous disorders are Lepra vulgaris
and Psoriasis vulgaris. The causes of Impetigo, Porrigo, and
Scabies, are probably similar to those of the true squamæ, for
they are often curable by similar remedies. The actual eruption
of Porrigo is accompanied by a parasitic fungus, which
may sometimes be transmitted from one person to another;
and a small insect or Acarus which haunts the vesicles has
been alleged as the cause of Scabies; but it is not, after all,
quite clear whether these attendants may not be merely the
concomitants or the results of these two disorders. At all
events, Lepra and Psoriasis are true blood diseases, and are
often inherited. They are more obviously under the influence
of Antisquamics than the other skin diseases.
It has thus been shown that the diseases in which Catalytics
are used are each to be accounted for by a process in
the blood. The fourth minor proposition will not be so
difficult to establish as the last, although it is in fact the most
important of all.
The action of a Catalytic results in the neutralization or
counteraction of one or more of these morbid agencies.
This has already been sufficiently proved. It is established
by experience that these remedies severally counteract the
diseases named. They have been shown to have an action in
the blood; and the diseases have been proved to be blood-diseases.
Thus it is clear, that if the former counteract the
latter, and have no action on the nerves, they must do it by
some agency in that fluid, over the particles of which both
exert an influence. They are Catalytic Hæmatics; i.e.,
medicines which, by an operation in the blood, are enabled
to counteract disorders which depend upon active morbid
agencies. This is all that can be positively affirmed of their
mode of operation.
The fifth and last minor proposition relates to an important
difference between these and Restorative medicines.—The
latter may remain in the system, for if they did not do
so, they could restore nothing to the blood. But Catalytics
cannot restore any thing, for they are generally unnatural to
the blood. They must sooner or later be excreted.
Catalytics are unnatural to the blood, and must at length
pass out of the system.
Of the list of Catalytics, the only medicines that occur as
constituents of healthy blood, are Alkalies, Salts of the
alkalies and earths, Chlorine, and Sulphur. Of these, the
Alkalies, and possibly also the others, are not unnatural to
the blood when administered in small quantities, and may
remain in the system and act as Restoratives, when there is
a deficiency in the blood of similar materials. But even
these substances, when given in large quantity, as is the case
when they are used for Catalytic purposes, are unnatural to
the blood, and must be excreted from it. With respect to
the other Catalytics, they cannot any of them remain naturally
in the blood, under any circumstances. Their very
presence for awhile constitutes an artificial disease, and is
only to be tolerated or recommended because it may serve to
counteract a morbid action of a more serious and uncontrollable
character.
The kidneys generally constitute the channel by which
these Catalytics are removed from the blood. Most of them,
in passing out, act as diuretics. To this we must, perhaps,
except the salts of lead, zinc, and copper. Doubtless some
are excreted partially or entirely by the mucous membrane of
the bowels, but this we cannot so readily appreciate. The
circumstance that the astringents just mentioned are efficacious
in diarrhœa seems to point to their access to the intestinal
surface from the blood.
It has already been shown that these Catalytics are all soluble
in some way in the intestinal canal, and that they are
absorbed. (Vide Prop. I.; Prop. II.) All of them that can
be detected by chemical means, have actually been discovered
in the blood. But the system will not, if it can be avoided,
suffer them to remain there long. The glands are charged
with the office of purging the blood of all morbid materials;
and thus these substances pass out in the secretions; most
particularly, as I have just said, in the secretion of urine.
Every one of the medicines of this division, enumerated
above,—excepting Colchicum and Pitch, which are difficult to
recognise chemically,—have been detected in the urine by M.
Wöhler, M. Orfila, and others. The Alkalies and Acids are combined,
so as to form salts; the vegetable salts are decomposed;
Sulphur has changed into Sulphuric acid; and the
metallic bases are found to be variously combined; but all
the fixed inorganic materials remain essentially the same,
however altered in arrangement. Many of these medicines
have been likewise detected in the secretions of other glands.
This subject will be further discussed in the consideration of
Prop. X., and does not immediately concern us now.
Thus the minor propositions may be considered as proved;
and all that I have ventured to affirm of this group of medicines
is, that they counteract morbid agencies by an operation
in the blood.
Now the mode of counteraction is not defined, because it
is only in a few cases that we can even guess at it. In the
majority of instances it seems inexplicable. We know that
Syphilis is a poison in the blood. Mercury also is a poison
in the blood. But why does Mercury antagonize and annihilate
Syphilis? The case is the same with Scrofula and
Iodine; with Lepra and Arsenic. It is very humiliating to
be baffled when we have got thus far; when, led by the hand
of Science, we have been conducted almost to the end of this
interesting inquiry, to find that we are perfectly unable to
take the last step, and thus to conclude our adventure.
When there is no disease, a Catalytic medicine may work
out its own action in the blood, and produce a disease. But
when there is some previous disorder, the working of the Catalytic
may operate so as to counteract this already existing
action, being so far similar to it, that it acts in the same department,
and may thus occasionally produce by an accident
like results; but being, nevertheless, as we have seen, essentially
contrary to it, because it neutralizes it.
Such opposite relations are met with even among natural
diseases. Vaccination and Small Pox afford us an instance
of the mutual counteraction of morbid processes. These
poisons are alike in their operation. Dr. Fouquet, of Freiburg,
has tried the effects of re-vaccination in Syphilis, on
the inmates of a large military hospital, with great apparent
benefit, as it is said. These poisons are unlike in their results.
So are Ague and Phthisis; and persons who have
had Ague are said to be less liable to Phthisis than others.
Again, we find that one attack of an eruptive fever preserves
the system in some way from the renewed operation of the
same poison. In these morbid phenomena we find something
of a parallel to the curious operation of Catalytic medicines
in controlling blood-diseases; for I have shown that
these remedies themselves are artificial blood-diseases.
Such ideas lead us on into the uncertain regions of speculation.
The idea that diseased actions may possibly be accounted
for by supposing the existence of special fermentations in
the blood, is by no means a new one. Inscrutable as these
diseased actions themselves may be, yet, we are enabled to
recognise processes of a nature analogous to fermentation as
going on in that fluid in health. Of such a kind probably
are, the change of albumen into fibrine; the changes which
take place in the starchy matters of the food before they can
be oxidized into carbonic acid; and the changes that must
occur in nitrogenous substances before absorption, as well as
those that accompany afterwards the downward progress of
the same materials, from living tissue into Urea and Uric
acid, to be finally excreted from the system. It is a curious
fact that nearly every known product of organic fermentation
has been discovered in the human body in health or in disease.
Lactic, butyric, and acetic acids, have been frequently found
there. Dr. Heintz has lately added to these succinic acid,
discovered in a hydatid cyst of the liver.
The production of many disorders by the access of a known
morbid material, the working of that material on the particles
of the blood after a special fashion peculiar to itself alone,
and the gradual elimination of certain products, also peculiar
to this one operation, are circumstances in which diseases
bear an obvious analogy to processes of fermentation. The
same remark applies to the working of Catalytic medicines.
It is then just possible that one of these medicines might
produce in the blood a fermentation which should meet and
neutralize the morbid fermentation; or that it might simply
determine the latter in a different direction, and thus bring it
to a desirable end. Acting in health so as to produce a morbid
change, it might operate in disease by means of diverting
into a right direction a change that is already going on in a
wrong one.
But let us leave generalities, and descend more into particulars.
Are we in a position to be able to indicate the
actual nature of the changes which we thus assume to be
probable?
The term Fermentation is used to express a change or series
of changes of a special character, caused among the particles
of a compound body, by the presence of a certain other body
called a Ferment. There are two kinds of fermentation. In
one the ferment itself is undergoing change, and impresses a
similar change upon a substance which is analogous in nature
to itself.[39] The process caused by a contagious disorder would
probably be of this kind. Just as the changing yeast forms
and increases itself out of the fermenting dough, so does the
virus of such a disease renew and propagate itself out of the
particles of the blood.
The other kind of fermentation is simpler in action, but
more incomprehensible in character. It is produced by mere
contact, without any change in the ferment itself. Thus it is
known to chemists that spongy platinum causes the combination
of oxygen and hydrogen, and exerts generally a powerful
influence over the affinities of gases and liquids, without ever
itself undergoing any change. The influence of Emulsine, in
causing, by mere contact, the Amygdaline in the bitter
almond to resolve into Prussic acid and other compounds;
and that of Pepsin or of Ptyaline, in promoting the change
of Starch into Sugar, is of this kind.
Considering that Catalytic medicines are not by their nature
changing bodies, being mostly minerals, it is not likely that
they could cause that kind of fermentation which requires
that the ferment itself should be in a state of change. The
influence of contact is the one which they would be most calculated
to exert. I may remark that I have used the term
Catalytic without any reference or allusion to this sense, in
which it has been frequently employed, but merely as conveniently
expressive of undoing or destroying. I would not
wish, either in the terms or in the propositions which I have
adopted, to assume for granted any thing which is not proved,
still less an idea which is purely hypothetical.
But it is not very unlikely that some of these medicines
may act in a mode which is more or less analogous to an action
of fermentation of the kind just described. They might
then either cause change themselves, and by this means alter
and destroy a morbid process somewhat similar to that which
they themselves excite; or they might, by simple contact, be
able to resolve this process into a natural direction. We have
seen that when introduced into healthy blood, they invariably
tend to produce a change in it which is productive of
harm; but that when there is already an abnormal process
going on there, their influence will effect the subversion or
annihilation of this other process.
And there are certain physiological considerations that
render such an idea still more intelligible and plausible.
It is to be remembered that the blood, in which we suppose
such actions to go on, is not an ordinary chemical fluid, subject
to common laws, and influences, such as we may meet
with out of the body; but a very complicated mixture, which
is ever circulating and being maintained at a high temperature,
and contains a number of compound organic bodies, each
of which is liable to a series of varied metamorphoses.
It is not a very potent agency which is needed to disturb
the chain of conditions of one of those inconstant bodies which
is thus continually performing the circuit of the system.
I may briefly exemplify the series of changes, simple but
momentous, which an organic body is capable of undergoing,
if I instance the combination of elements which constitutes
Urea.
By bringing Ammoniacal gas in contact with the vapour of
Cyanic acid, we produce Cyanate of Ammonia, a poisonous
salt. This, when exposed for some time to the air, changes
into Urea, which is isomeric with it, but comparatively innocuous.
Urea, when heated, gives off Ammonia, and becomes
Cyanuric acid. On again heating this, hydrated Cyanic acid
sublimes. This, when brought in contact with water, becomes
Bicarbonate of Ammonia. Two equivalents of Cyanic
acid, uniting in one compound, produce Fulminic acid. This,
if combined with the oxide of Silver or of Mercury, forms a
compound which is caused by the slightest friction to explode
with terrific violence. If to the elements of this dangerous
acid be added those of two equivalents of Ammonia, we again
have Urea, a substance which is continually forming in the
body by the oxidation of some of the nitrogenous tissues.—Urea
with water changes lastly into Carbonate of Ammonia.
These several compounds, alike or identical in their ultimate
composition, are possessed of very different properties, whether
regarded as medicinal or as chemical agents.
A similar set of changes may be produced among the elements
of Uric acid, also an animal product.
Changes in some respect similar to these which are produced
by the Chemist are no doubt continually going on, or
capable of being set up by various influences, in the circulating
blood, which is at a heat fit for such processes; in which also
is a considerable quantity of free oxygen, as well as soda,
ammonia, and other elements, in a state fit for combination;
and to all these is superadded the agency of the vital principle,
the object and effect of which is continual alteration,
destruction and reproduction.
By supposing the establishment of a set of changes in the
blood, we may possibly gain some insight into the cause of
the powerful effects of some apparently insignificant medicines
belonging to this division of Hæmatics. Neurotic medicines
appear to act by their mere presence, contact and excitation.
This may not always be the case with Catalytics. Their
power cannot in all cases be clearly accounted for by a simple
and direct influence on the blood, the muscles, the nerves, or
any of the tissues. It seems sometimes as if it were on the
processes that their presence sets going, and on the products
thus generated, that their influence and power depend.
It may be observed that this idea of action by contact cannot
by any means be supposed to favour the very unreasonable
theory of the efficacy of infinitesimal doses of drugs. For
such medicines must of necessity be present in some amount,
or they cannot act at all. Their operation cannot be like that
of the putrefying yeast, or of the poisons of contagious fevers,
each of which can reproduce itself out of the elements of the
changing or fermenting body. For Antimony, Mercury, and
Iodine could never make themselves out of blood, which does
not contain them. Like the Emulsine in the production of
Hydrocyanic acid out of the material of the bitter almond,
they must be present in certain quantity, or they are quite
inoperative. Even a tenth of a grain would generally be
powerless, not to mention such irrational quantities as the
thousandth, millionth, or even decillionth of a grain. (Vide
page 54.) Experience—better even than theories and mathematics—is
entirely opposed to such chimerical fancies.
Having thus entered into a speculation concerning the
probable action in the blood of Catalytic remedies, I must
once more remark that this idea forms no part of the Proposition
in which I have defined their mode of operation. In
the present state of our information on the subject, we cannot
certainly say more than that these remedies, by some blood-action,
are able to antagonize and to annihilate certain disorders
in the blood.
The resolution of a disease thus effected may, in some few
instances, be partly explained by certain chemical considerations,
as will be particularly shown in the case of Antiarthritics.
It remains for me now to add some brief remarks on the
individual modus operandi of the substances included in each
of the eight orders of Catalytic medicines.
Some of these having been partly discussed above, in
arguing the Proposition, it will not be found necessary to
travel over again that portion of the ground which has already
been thus traversed.
Ord. I. Antiphlogistics.
The inflammatory process—the chief seat of which, however
it may first originate, is in the circulating blood—exerts
a powerful influence over the nervous system, and may, by
this influence, cause death. When fever is produced to any
extent, there must be danger.
We are enabled in two ways to control or to mitigate this
state of things. We may produce an action on the nervous
system, or we may direct our attention to the process in the
blood.
Of Neurotic medicines, which we shall have to consider
hereafter, there are some which may be made use of at the
commencement of the attack, and others which are appropriate
when the process is more advanced. Of the first kind
is Antimony, considered in its Neurotic action. Employing
it in large doses, we may produce a powerful effect upon the
nerves which supply the heart, and thus, by diminishing the
impulse upon the inflamed parts, or on the vascular system
generally, promote absorption and resolution. Blood-letting
produces the same action, but in an inverse mode. Antimony
diminishes the pressure on the vessels by weakening the force
of the heart; Blood-letting weakens the force of the heart by
diminishing the pressure on the vessels.
Such Neurotics as Opium are employed at a more advanced
stage, when the inflammation cannot be suddenly put a stop
to, and our object is to counteract the effects it has produced.
Besides relieving the pain and nervous irritation which are so
much to be dreaded, Opium may be employed to prevent a
blood-medicine from passing out through the bowels. Antimony
and bleeding are appropriate in sthenic cases. Opium
should not generally be employed in these instances, nor
should it be given in brain disorders, or in any case where
there appears to be a determination of blood to the head.
Certain medicines of the class of Eliminatives, and certain
Catalytic remedies belonging to the present order, are employed
to counteract the inflammatory process in the blood.
Of the former, the most important are Purgatives and Diaphoretics.
By diminishing the amount of the serum of the
blood, they not only tend to check effusions, but act indirectly
on the heart, in the same way as the medicines last spoken
of; and they probably also promote the passage of morbid or
of peccant materials out of the system through the glands.
Acid and saline drinks may act as Diaphoretics, besides
exerting each a peculiar influence in the fluids.
Of this Catalytic order, Antimony and Mercury are those
which tend most powerfully to check the general blood-process
of inflammation. The former is used in urgent and
acute cases to make a sudden and powerful impression, adding
to its Hæmatic action a sedative effect on the heart and circulation.
Mercury exerts no such immediate influence. Diminishing
the Fibrine of the blood, and having other operations
of a peculiar kind in this fluid, it powerfully promotes absorption
and counteracts effusion, in all inflammations. The blood-action
of these remedies, though not positively slow, is slow
when compared to an action on nerve. Thus when Antimony
is given in large doses, as is desirable in some highly sthenic
and dangerous attacks, its blood-action is lost in its immediate
Neurotic operation.
So that in Croup and Pneumonia, both rapid and fatal inflammations,
Antimony is far preferable to Mercury. But
in Pleurisy—where there is generally no immediate danger to
be dreaded, but a subsequent effusion, Mercury is best, being
in time to lessen or to prevent this result.
From the action of both on the blood, and one on the nerves,
these are very lowering remedies. In the employment of
Antimony in fevers and inflammations, the production of
nausea generally indicates that it has taken sufficient effect;
but it may sometimes be better to give such a dose as shall
cause vomiting, especially when a violent counter-irritant
action is to be desired. The increase in the quantity of saliva,
and slight soreness of the mouth, which result from its action,
will show when the administration of a Mercurial has gone
far enough. It is seldom advisable to cause copious salivation.
Alkalies dissolve the Fibrine of the blood, and appear by
this to lessen its deposition, and retard its formation. Thus,
when given in large doses, they operate as Antiphlogistics.
They have sometimes been employed with advantage in fevers
of the acute or sthenic kind. Exerting an influence over the
inflammatory process considered per se, Alkalies and Mercurials
are more particularly efficacious in some special varieties
of inflammation, because in such cases they further
counteract the morbid agency by which the process is excited
and kept up.
In the Typhoid and Eruptive Fevers, when the blood is
already sufficiently deteriorated, and it is not desirable that
we should reduce the vital powers beyond a certain point,
Salines, as Nitrate and Chlorate of Potash, supply us with a
set of valuable and sufficiently mild Antiphlogistic agents.
It seems that they both exercise a solvent power over Fibrine,
and keep asunder the corpuscles which tend to adhere together
in inflammatory blood. This latter action has been
observed by Mr. Gulliver. Salts are excreted, and act on
the skin, or the kidneys, or the bowels. They are not so
potent as Alkalies; for salts pass out of the body as they went
in; but Alkalies pass out into the secretions as salts, having
first combined with acid in the system, so that they must
leave behind them a certain excess of alkali in the blood, by
which their action is continued for some time. (Vide Alkalies;
Prop. VIII.; Antimony and Mercury in Chap. IV.)
Ord. II. Antisyphilitics.
These are medicines whose operation in the blood results
in the counteraction or neutralization of the syphilitic poison.
In primary forms of Syphilis, as the chancre, and early
eruptions,—as syphilitic Lichen, Roseola and Lepra,—also in
syphilitic Iritis, Mercury is the single and best remedy.
Its power is universally admitted, both by English and
Continental surgeons. It is often esteemed a specific.
Among others, Mr. Hunt, in a treatise on Syphilitic eruptions,
maintains that Syphilis has a tendency to go on without limit
if left alone, but that Mercury in sufficient doses possesses the
power of totally destroying the poison, and preventing its
transmission.
Mr. Carmichael was of opinion that Mercury was only applicable
in those cases which exhibited the true Hunterian
chancre, round, cup-like, and hard, followed by a leprous
eruption. But it is more in accordance with common experience
to say that the only contra-indications to the use of
Mercury in primary Syphilis are these—a scrofulous or very
debilitated state of the system; and a sloughing or irregular
appearance of the primary sore.
We may administer Mercury in two forms. It may be
given as Calomel or Blue pill, with or without Opium, and
continued until it affects the mouth. Or the Bichloride may
be administered in minute doses, and may prove efficacious
without producing salivation. It should be commenced as
early as possible; and in most cases the action of Mercury in
the blood, of whatever nature that action may be, will meet
and neutralize the advance of the syphilitic virus, preventing
its further manifestation in a secondary form. It is rarely
necessary to push its action beyond the first symptom of salivation;
for that will be evidence that the system is sufficiently
saturated with it. Beneficial as it often proves when administered
thus cautiously, yet, if given in excess, or to individuals
that are over-susceptible of its action, it is capable of
proving a poison every whit as noxious as the Syphilis which it
was intended to neutralize. The mercurial cachexy is quite
as deplorable, and quite as incurable as the Syphilitic cachexy.
The Terchloride of Gold may be used in Syphilis in the
same way as the Bichloride of Mercury; but it is much more
seldom employed. There seems to be a strong medicinal as
well as chemical similarity between these two metals and
their compounds. Even the insoluble metal itself was used
some time ago as an Antisyphilitic, apparently with success.
In 1715, Dr. A. Pitcairn recommended finely-powered Gold
as even more efficacious than Mercury in the treatment of
Syphilis.
In secondary forms of this disorder, as in Periostitis, ulceration
of the mouth and throat,—or in any of the late rashes,
as Rupia,—Iodide of Potassium is the best remedy. Its efficacy
in such cases was discovered by the late Dr. Williams.
It may sometimes fail to effect a cure; but this failure is often
due to the omission of Mercury in the treatment of the primary
disease. It would seem as if it were not so much the
real secondary syphilis, but a certain smouldering action of a
part of the poison which has escaped the operation of Mercury,
but has been modified by it, which is capable of being
met and controlled by Iodide of Potassium. In cases where
this remedy fails, I have found that a course of the Bichloride
of Mercury, combined with Sarsaparilla or some bitter tonic,
proves very beneficial.
But the action of the Iodide on a case of Periostitis, and
the rapid absorption that follows its exhibition, are sometimes
fully as remarkable as the influence of Mercury over the primary
disorder.
Sarsaparilla is a very doubtful member of this order. It
contains a soluble principle called Smilacine. It is thought
by some to purify the blood, and also to have a kind of specific
influence over it in old syphilitic cases. If it were so, we
should have from the vegetable kingdom a distinct analogue
to one of these mysterious mineral Catalytics. But it is so
rarely given without being combined with some more powerful
agent, that it is difficult to judge whether or not it may have
any striking virtues of its own.
The Antisyphilitics, particularly the insoluble compounds
of Mercury, are frequently employed as local applications to
sores and eruptions. When these have a syphilitic origin,
the mercurial doubtless combats the local manifestation in
the same way that it can counteract the general action in the
blood. In other cases the Mercury may pass into the blood
of the part, and, by exerting in its antiphlogistic operation,
the result of which is to diminish its plasticity, may thus promote
absorption. Mercurial ointment, if rubbed into the
skin, becomes in part absorbed, and may thus produce salivation.
Ord. III. Antiscrofulics.
These are medicines which have the power of counteracting
the poison of Scrofula in the blood. Common and pernicious
as is this disease, there are not many Catalytic remedies
which exert any marked control over it. When a strumous
condition is chronic, and has firmly established itself—when
it has descended through many generations of the same family,—it
is very intractable and difficult to cure. Palliative and
indirect remedies, aimed rather at the consequences than at
the source of the disorder, are often adopted with benefit.
Tonics, Chalybeates, Cod-liver oil, and cold bathing, are frequently
of use in improving the condition of the system, when
debilitated by the long continuance of strumous disorders.
But the most important and direct remedies for Scrofula are
to be found in Iodine and its compounds.
It is not to be wondered at that in many cases of deeply-rooted
blood-disease, complicated perhaps with anæmia,
structural change of organs, disordered assimilation, and
various nervous symptoms, all remedies alike should prove
useless. So that the experience of many practitioners, thus
frequently disappointed in their hopes of a cure, has led them
to question altogether the efficacy of Iodine in Scrofulous disorders.
But it is generally allowed that it is more beneficial
in such cases than any other medicine, and is the only remedy
which is universally applicable in Scrofula. If this be true,
it follows that it must have a special power over this blood-disease.
Burnt sponge, and the ashes of a seaweed, the Fucus vesiculosus,
both of which contain Iodine, have been used in Scrofula
from very early times. But it was not until the present century
that Iodine was discovered, and its efficacy in Scrofula,
particularly in the cure of Goitre, pointed out by Dr. Coindet
of Geneva. After this it came to be generally applied in all
Scrofulous cases, and was especially recommended by M.
Lugol in France, as a specific for such maladies.
When given for some time, Iodine has the effect of impoverishing
the blood, like Mercury and many other Catalytics,
diminishing in it the amount of Fibrine. All remedies which
do this favour absorption. This effect is obviously connected
with the alteration in the blood, and there is no reason to
suppose that any special stimulant action is exerted on the
absorbent vessels. Those Catalytics which favour absorption
are not all useful in the same cases, but some are most useful
in one disorder, some in another. Thus they must exert a
special action over morbid poisons; an action which is altogether
distinct from the influence over absorption, although
by this latter they may be able to cause the disappearance of
effused products, and of tumours produced in various ways.
In some rare cases Iodine has even been known to cause the
absorption of healthy glands, as the mammæ and testicles.
Iodine and Iodide of Potassium, when successful, do not
merely cause the disappearance of scrofulous tumours, but
further meet and neutralize the poison which is working in
the system, and effect a more or less permanent cure. This
could hardly be done by a remedy which had only the power
of promoting absorption.
It seems that some systems are able to bear with impunity
very large doses of Iodide of Potassium. I once met with a
medical man who denied its power altogether, because he
himself had frequently taken a scruple, and sometimes a
drachm at a time, without any effect. Other men are readily
affected by very small quantities, and quickly experience the
symptoms of Iodism. It is probable that in the former case
the medicine is very quickly eliminated by the kidneys; but
that in the latter it remains in the system for some time.
The Iodide of Iron is a most useful medicine for scrofulous
children, who commonly suffer under Anæmia, as it combines
a Chalybeate with an Antiscrofulic action.
Bromine and Chlorine resemble Iodine in their Antiscrofulic
effects. It is said that Scrofula and Consumption are
unknown among the workmen in bleaching factories, where
Chlorine is being constantly inhaled. Thus it has been
strongly recommended that diluted Chlorine should be constantly
inhaled by consumptive patients. It is probable
that part of the efficacy of sea-side air and sea-voyages in
scrofulous cases may be due to the free Chlorine which is
given off in small quantities from the salt water of the ocean.
The powers of Iodine and Bromine are shared by their compounds;
and probably Chlorine is no exception to this rule.
The bad consequences which follow the omission of common
salt from the food, are sufficient to show that this substance
has a beneficial action on the blood. Probably large doses
of this article of diet would be found advantageous in Scrofulous
disorders.
It is easy to recognise such an action as that of Iodine
in Scrofula, but it is almost impossible to invent a satisfactory
explanation for it.
Potash, free or carbonated, is another remedy of considerable
importance in Scrofulous diseases. It is possibly one
of those Catalytics which exert a simple chemical influence.
It may act by holding in solution fibrinous and fatty matters,
and preventing their abnormal deposit in a crude form in the
shape of tubercular matter. It may also be found useful in
cases of Syphilis, when aggravated by a previously existing
strumous tendency, and where a course of Mercury cannot
be safely prescribed.
Small doses of Mercury, as an alterative, are often efficacious
in scrofulous constitutions. They appear to act simply
by stimulating the torpid liver to a performance of its proper
function.[40] (Vide page 144.)
Potash has been used as a prophylactic against Consumption.
The efficacy of Cod Oil in this disease has been explained
by some as depending on the Iodine which it contains
in small quantities. I do not consider this explanation to be
the correct one. (Vide Cod Oil, in Chap. IV.)
Ord. IV. Antiarthritics.
In this order are included some blood-medicines which
exert a direct influence over certain disorders which depend
on some fault in the complicated processes of assimilation and
nutrition. The chief of these diseases are, Diabetes; Oxaluria;
Lithic deposit in the urine; and the true Arthritic disorders,
i.e., Gout and Rheumatism. Most of those blood diseases
which cannot be clearly traced to the introduction of a poison
from without may be arranged under this head, and appear
to be curable by the same set of remedial agents.
There are certain processes always going on in the blood,
whose continuance in the right direction is essential to health.
When one of these processes is disturbed, it does not generally
cease, but it goes on then in a wrong direction.
The natural processes result, on the one hand, in the preparation
of fit and proper nutriment out of the materials of
the digested food, for the growth and support of the several
tissues and functions; and, on the other hand, in the gradual
change and conduction out of the body of the products of the
waste of those tissues. But when any process goes on in a
wrong direction, it results in the formation of various products
different from those which are required, and which the
kidneys and other glands are at length called upon to excrete
from the system. The result is that the general health is
more or less seriously impaired.
There is also another way in which these diseases are not
unfrequently caused. A natural process may stop at a certain
point, and go no further. The material formed at that
stage remains as it is. It is not wanted; it is morbid; and
it also is excreted from the body. It is possible that these
errors in the assimilative processes may sometimes arise in
the first instance from a deficiency in the blood of some substance
whose influence was necessary to the proper conduct or
control of the natural series of changes. Some of these conducting
materials may be formed by the liver; for it is found
that these disorders are very commonly connected with an impairment
of the function of that organ. Thus Mercury, which
restores the secretion of the liver, is often useful in Arthritic
disorders; as also is Quinine, which has already been shown to
have a peculiar relation to liver diseases.
But these disorders, however they may first originate, consist
in an active morbid process of one kind or another; and
the surest way of counteracting this process, or of diverting it
into a right direction, is by the employment of one of the
Catalytic medicines contained in this order. Some stages of
these diseases are attended with a want in the blood of some
of its ordinary constituents; which condition may be relieved
by the supply of a Restorative remedy.
Thus in this group of disorders three kinds of medicines
may be employed, which tend in various ways to improve the
condition of the blood.
Acids and Alkalies are sometimes needed, and act on the
Restorative principle. The true Antiarthritics are those medicines
which are employed on the Catalytic plan, to meet and
neutralize the morbid material or process in the blood. And
sometimes Eliminatives are made use of, which seem, by acting
on the secretions of the skin, kidneys, or bowels, to be able
to rid the blood of an unnatural product. Thus Guaiacum
and Salines are employed in Rheumatism, and Purgatives in
Gout.
These two joint affections are most characteristically under
the influence of Catalytic remedies. Diabetes and Lithiasis
are more under the control of Restoratives than the others.
The medicines composing this fourth order of Catalytics
have been already enumerated.
That Colchicum tends in some way to neutralize in the
blood the poison of Gout, and to a less degree that of Rheumatism
also, is generally admitted, although various theories
have been adopted to explain this action. (Vide Chap. IV.
Art. Colchicum.)
In Oxaluria, the employment of Nitric acid as a remedy
was first recommended by Dr. Prout. Dr. Golding Bird
advised the substitution of Nitro-hydrochloric acid, which has
proved to be a most valuable remedy, not only in this disorder,
but also in some cases of lithic deposit. The Oxalate
of Lime rarely occurs alone in the urine; there is generally
along with it some Urate of Ammonia. The causes of the
two deposits appear to be in some way connected. So also
are the remedies similar. Dr. G. Bird has found Colchicum
to be of signal service in cases of lithic deposit in the urine;
and has proved the same medicine to be efficacious in Oxaluria.
I will now attempt to show how the action of these medicines
may admit, on certain grounds, of a chemical explanation.
There are very few Catalytic actions in which such an
explanation can be attempted, but a degree of plausibility appears
to attach to the idea in this case, though it cannot of
course be considered to be susceptible of more than a demonstration
of probability.
I have already said that in all the disorders now under consideration
there are certain morbid constituents in the blood
which have been recognised by chemical tests. In Diabetes
there is an excess of grape-sugar formed in the blood, and
excreted from it in the urine. In Rheumatism we have a
painful joint affection, attended with a great development of
acid in the system; and this acid, which we have many reasons
for supposing to be lactic acid, is occasionally excreted
by the skin. In Gout we meet with another Arthritic affection,
in which there is urate of soda in the blood, and an
excess of uric acid and urea in the urine. A simple excess
of uric acid in this secretion constitutes Lithiasis. There is
an obvious but ill-understood connexion between the last two
disorders, and, indeed, between all those of which we are
treating. In Oxaluria we have an abnormal formation of
oxalic acid in the blood, which is excreted in combination
with lime, for which base it has a great affinity. In oxalic
urine there is generally an excess of urea, as I have found in
many cases.
Now it seems to me that all these disorders are capable of
being explained by reference to the series of changes in the
blood which are associated with the respiratory process.
(Vide Liebig's Anim. Chem., part i. p. 133; Dr. B. Jones'
Anim. Chem., pp. 20, 118.)
It is the general opinion of modern chemists, that before the
starch of the food can be applied to the maintenance of the
animal heat, for which office it is chiefly intended, it passes
through a series of chemical changes. First, assuming two
equivalents of water, it becomes grape-sugar; next, this
changes into lactic acid, which is isomeric with it; and this
again combines with twelve atoms of oxygen, to form carbonic
acid and water. This last change is a process of combustion,
and thus produces heat. The oxygen needed for it
is absorbed from the air by the pulmonary mucous membrane,
and the carbonic acid formed passes out of the blood
at the same surface.
Liebig was the first to point out the connexion between
these changes and the phenomena of Diabetes. It is clear
that if the process were to stop at the formation of grape-sugar,
the condition of blood that exists in Diabetes would
result. This sugar cannot be put to any use, and is excreted
as fast as formed. There is an excess of urea in the whole
quantity of urine passed in the day; probably because the
nitrogenous food and tissues are undergoing combustion instead
of the starch. Before becoming grape-sugar, starch
undergoes a transitional change into Dextrine, a gummy insipid
substance which has the same composition as itself. It
seems that the process may even stop as early as this, and
that by this stoppage another analogous disease may be produced,
i.e. Diabetes insipidus. The common Diabetes is called
D. mellitus. (Vide Jones' Anim. Chem. p. 120.)
If it were clearly proved that the acid of Rheumatic fever
is lactic acid, then this affection might evidently be produced
by a stoppage of the process at the next stage. Lactic acid
has been formed; but, for some reason unknown, it is not oxidized
into carbonic acid. Urea and uric acid are in excess
in the urine, from the cause alleged above.
But suppose some of the sugar to be oxidized prematurely,
without passing first into lactic acid. By this oxalic acid
would be produced, and the phenomena of Oxaluria accounted
for.
These things are only alleged as possible, and for the purpose
of showing that, should they be true, the action of some
useful remedies might be elucidated. It is not at all unlikely
that the accuracy of such ideas may be completely established
by fresh discoveries at no distant time. But let us continue.
In Gout and Lithiasis there is an excess in the system of
nitrogenous matter, and thus a tendency to an extra formation
of urea. These conditions are often brought on, and
always aggravated, by over-indulgence in animal food. Now
if we may suppose that some of the lactic acid, instead of
oxidizing directly into carbonic acid, oxidizes in combination
with this urea which is in excess, then uric acid and water
might result, as is shown below. The uric acid passes out
into the urine in excessive quantity.
Should this be the case, the great affinity existing between
the course and symptoms of Gout and Rheumatism would be
easily explained, there being in both disorders an impediment
to the proper oxidation of lactic into carbonic acid.
These things may be illustrated by a diagram, showing the
results which are supposed to take place when the natural
process is arrested at, or diverted from, any of its stages:—
Starch.
|+
|2
|a
|q
|=
Grape Sugar (Diabetes.)
|
|\
| \
| \+ O =
| \
| \
| \ Oxalic acid. (Oxaluria.)
|
|=
Lactic acid (Rheumatism.)
|
|\
| \
| \+ 2 Urea + O 6 =
| \ Uric acid + 10 aq. (Gout, and Lithiasis.)
|+
|O
|=
Carbonic acid.
Thus, at each of the two transitional stages, we might
have one diseased condition produced by an arrest of the
process, and another by its deviation. These deviations and
stoppages may result from a failure of some natural principle
which is gifted with the control and direction of the series of
transformations; or they may simply be traceable to a want
of vital energy, or nervous force.
The same ideas may be more distinctly expressed by a few
chemical equations.
Natural process.
C12H10O10 + 2 HO = C12H12O12.
= 2 (C6H5O5, HO.)
C6H6O6 + O12 = 6 CO2 + 6 HO.
Oxaluria.
C12H12O12 + O18 = 6 C2O3 + 12 HO.
Gout and Lithiasis.
Lactic acid + 2 Urea + O5 = Uric acid + 10 HO.
The last equation may be thus proved at length:—
C6H6O6. C10H4O6N4.
C4H8O4N4.
O6. H10O10.
—————— ——————
C10H14O16N4. = C10H14O16N4.
It is next to be inquired how far the theoretical explanation
of these diseases which has thus been sketched out can be
applicable to the matter in which we are more immediately
interested, viz., the action of the Catalytic remedies used to
cure them.
For the radical cure of Diabetes there is no known remedy;
though some relief may be afforded by a system of dieting.
(Vide Aliments.) It is supposed that what we have to do is to
convert diabetic sugar, i.e. grape-sugar, into lactic acid. This
acid probably exists in the gastric juice. And some such substance
as Pepsin, or the decomposing Caseine in sour milk,
which is capable of effecting this change out of the body,
might perhaps avail us, if we could contrive to introduce it
into the blood.
In Oxaluria, the best treatment consists in a course of
Nitro-hydrochloric acid. This remedy is prepared by adding
one part of Nitric to two of Hydrochloric acid; and is diluted
considerably with water when prescribed. The Nitric
acid causes the oxidation of some of the Hydrogen of the
other acid, and thus sets free Chlorine gas. This is stated by
Mr. Brande to go on until the liquid is saturated with this
gas. The result of the presence of Chlorine is, that from the
affinity of this gas for Hydrogen, by which, under certain
circumstances, it is enabled to set free the Oxygen of water,
this compound acid becomes the most powerful oxidizing
agent known. This acid has been lately used as a remedy
for Gout and Rheumatism, in spite of the acid state of the
fluids in those cases; and I believe it to be a very valuable
medicine in both of these disorders. A simple mineral acid
would do no harm in both instances. The Nitro-hydrochloric
acid must operate in some special way.
It is probable that its action may depend upon its oxidizing
power.
In Oxaluria it might cause the oxalic acid to be oxidized
into carbonic acid, and thus restore health. Thus:
In Rheumatic fever, where we have supposed that lactic
acid is formed as it should be, but then stops short, and proceeds
no further, the oxidizing agent may convert this into
carbonic acid.
In Gout and Lithiasis, where there seems to be an excess
of nitrogen in the system, and thus more oxygen is needed
to restore the equilibrium, I have supposed that lactic acid
and urea are changed together into uric acid. If we adopt
this hypothesis, it will be evident that under the above treatment
this uric acid may be oxidized back into urea and carbonic
acid, and the balance of health restored. Thus:
Uric acid + 6 O + 4 HO = 2 Urea + 6 CO2,
which may thus be proved:
C10H4N4O6
O6 C4H8N4O4.
H4 O4 C6 O12.
————— —————
C10H8N4O16 = C10H8N4O16.
Such may be the action of Nitro-hydrochloric acid. It exerts
a true Catalytic or counteractive influence. But we have to
explain the agency of another class of very different, and apparently
opposite remedies. Alkalies are employed with benefit
both in Rheumatism and in Gout; particularly in the
former disease. Now I conceive these to act, in Rheumatism
at least, simply on the Restorative principle; supposing
lactic acid to exist in excess in Rheumatic blood. This by
itself may have no more tendency to oxidize into carbonic
acid, than so much vegetable acid would have. In ordinary
cases a free vegetable acid passes out into the urine without
undergoing any change in the system. But it has been proved
by Wöhler that the same vegetable acid becomes oxidized
when given in combination with an alkali. So that if we introduce
into Rheumatic blood a free alkali, a lactate of potash
or of soda will be formed; this may then be enabled to oxidize
into a carbonate, and the natural process be completed. Such
appears to be the rationale of the action of alkalies. They
would be inefficacious in Oxaluria, because the oxalic acid has
so great an affinity for lime, that it could not be separated
from this combination by an alkali.
Dr. Rees and others have found Lemon juice of great use
in the treatment of acute Rheumatism. It contains Citric
acid, and some Citrate of Potash; the latter being in too
small amount to explain the action of the remedy. I have
already shown how it seems possible that the vegetable acids
may act as refrigerants in simple fever; how they may then
supply the place of the natural lactic acid in the blood, and
become oxidized instead of the Proteinaceous compounds.
(Vide Acids.) But Rheumatic fever is a very different case,
for there is here apparently an excess of lactic acid, and an
arrest of its oxidation. In considering, however, the formula
for Citric acid, we perceive that not only does it contain proportionally
more Oxygen than Proteins, as was proved in the
former instance, but more than lactic acid contains. It is
Thus it is possible that it may act as a carrier of oxygen to
the lactic acid, and so help it on towards its transformation
into carbonic acid. It appears to be decomposed in the system,
for Dr. Rees has never known it in these cases to increase
the acidity of the urine. The matter is obscure; but
we can discern enough of it to convince us of the possibility
of different medicines acting in diverse ways so as to produce
very similar results.
Colchicum has apparently some power in the diversion or
control of these morbid processes, which we can only indicate,
but cannot further comprehend. It is generally best to give
it so that it shall neither produce purging, nor any great degree
of general depression.
Mercury and other medicines which promote the secretion
of the liver, are found to be of considerable use in the treatment
of all of these diseases, but more especially in Gout.
They seem to act by virtue of their power in eliminating and
producing Bile. And it is likely that some constituent of
Bile, reabsorbed into the blood, is able to exert a beneficial
influence on the conduct of such processes as those which we
have just now considered.
Quinine and Tonics have been strongly recommended by
Dr. Todd in Gout; and they seem to be signally efficacious,
both in this and in the other Arthritic disorders. This is a
very interesting fact. If there should be any truth in an idea
which I have explained at length in the article on Tonics
(vide p. 142,) it would seem that these Tonics may be of use
by supplying in the blood the place of one of the wanting
elements of Bile. For in all Arthritic disorders there is
more or less of hepatic derangement.
There seem then to be six separate and distinct explanations
of the cure of these Arthritic diseases. There are six
different modes of operation by which the same beneficial result
may follow the employment of Nitro-hydrochloric acid,
free Alkalies, Lemon juice, Colchicum, Mercury and Quinine.
So that if it should be proved, which is not unlikely, that
the chemical theory propounded above for the purpose of accounting
for the production of these disorders in the blood
is a correct view of the case, then this explanation of the
action of the various remedies used in such diseases would
acquire an additional probability. But at present the idea
is purely hypothetical, because depending upon a number of
things which, although they seem likely, are far from being
proved as yet.
All that we can affirm with any degree of certainty is that a
number of blood-medicines are applied with advantage to the
treatment of these kindred disorders, tending to counteract the
morbid conditions by which they are severally produced. These
Antiarthritics must operate, then, on the Catalytic principle.
A number of varieties and masked forms of these disorders
are grouped together under the general title of Dyspepsia.
The depraved condition of the blood which tends to the
production of arthritic symptoms may, when controlled and
disturbed by various causes, simply manifest itself by causing
acidity of the stomach, flatulence, impairment of digestive
power, and general lassitude. Different Antiarthritic remedies
are applicable in different cases. Colchicum or Nitro-hydrochloric
acid are serviceable when this condition of the
system is of long standing. Small doses of Mercury are
often efficacious. Tonics, and a Purgative occasionally, may
be recommended in milder forms of the disorder.
Ord. V. Antiscorbutics.
These are remedies which are useful in the counteraction
of Scurvy and Purpura. In these disorders there is a thin
and poor condition of the blood, together with a deficiency in
the amount of albumen, fibrine, and the solids generally; a
tendency to hæmorrhages and ulcerations, consequent on this
condition of the blood; and great general depression and debility.
There is no doubt that these changes in the blood are due
to a certain morbid action. It seems that there are some
kinds of food which are able to prevent the occurrence of this
morbid action, or to control it when it has been set up. The
worst forms of Scurvy occur among sailors in long voyages,
who have been deprived for some time of fresh vegetable
food; and it is often observed that those who have been thus
afflicted on land have been subjected to the same deprivation.
But it does not follow as a matter of course that those who
are thus deprived become invariably the victims of Scurvy.
It seems that there are certain constitutions which are more
disposed to it than others; and that when these systems are
deprived of some articles of diet which are able to prevent or
to neutralize the working of the poison in them, the latent
morbid action is allowed to commence.
Of all the substances of which trial has been made, Lemon
or Lime juice, and Potatoes, are said to be of the greatest use
in the treatment of scurvy. The former is generally employed
on board ships. These both contain Citric acid and
salts of potash. But the chief agent in the cure should be
something which is not contained in the food eaten by those
who are commonly attacked with Scurvy. The food of the
sailors who are thus afflicted consists mainly of salted beef
and sea-biscuit. Both contain salts of Potash; neither contain
Citric acid. So that from this consideration it would
seem as if the free acid must be the remedial agent. Vegetables
in their fresh state generally contain a small quantity
of this or some other acid; and fresh vegetable food is always
the best prophylactic against Scurvy and Purpuric diseases.
Various wild herbs, some of which contain Oxalic instead of
Citric acid, are used among the poor for this purpose.[41]
Dr. A. B. Garrod is of opinion that Scurvy is attributable
to a deficiency in the system of the natural amount of the
salts of Potash; he therefore treats it with salts of Potash,
and apparently with success. (Monthly Journal of Medicine,
January, 1848.)
The salts of Potash, if used on such grounds, would obviously
act as Restorative agents, and supply to the blood a
material in which it is deficient. But Citric acid could not
remain in the blood; and if it cures Scurvy, it must act on
the Catalytic principle. It could not supply to the system
any permanent material.
Dr. Garrod concludes from analysis that the antiscorbutic
articles of diet are distinguished by containing an abundance
of the salts of Potash, but that the reverse is the case with
the materials which form the staple food of those who are
most liable to Scurvy.
He gives the following as the amounts of potash obtained
from one ounce of each of the articles of diet named:—
| Wheaten bread | .259 grains. |
| Oatmeal | .054 " |
| Salted beef | .572 " |
| Boiled potatoes | .529 " |
| Lemon-juice | .846 " |
Thus it appears that lemon-juice and potatoes contain more
Potash than wheaten bread, and much more than oatmeal.
But they do not so much excel salt beef in this particular,
and that is one of the chief articles of diet among sailors.
And if this deficiency of Potash were the sole cause of Scurvy,
then it should be unknown in Ireland, where quantities of
Potatoes are eaten, and very common in Scotland, where
Oatmeal forms so important an article of diet among the
peasantry. I am certainly not aware that such is the case,
but believe it is rather the reverse.
In spite of the very able arguments and the instances adduced
on the other side, it seems to me that the probability
is still in favour of the vegetable acid being the active or
curative agent in these antiscorbutic vegetables. It seems
to exert a purifying power over the blood in this disorder, of
the exact nature of which we are not aware. It is probably
not only Citric acid that is efficacious, for it appears that
some other vegetable acids, and vegetables which do not contain
Citric acid at all, may be used with advantage in Scorbutic
diseases.
Ord. VI. Antiperiodics.
Certain mineral medicines of the Catalytic division are employed
in the treatment of periodic disorders.
Arsenic is a medicine of considerable power, which, when
given in too large a dose, or indeed when given at all in most
cases, becomes a poison. It has already been shown to act
in the blood, and to produce in it a number of effects of a
particular kind. One part of this operation is that it is capable
of antagonizing the poisons of intermittent disorders,
as also of certain convulsive affections and skin-diseases. In
health a poison, in disease it proves a remedy. But the
dangerous nature of its action is such as to demand considerable
care in the administration of the preparations of Arsenious
acid.
Dr. A. T. Thomson states that the action of Arsenic is
liable to exacerbations and remissions, and sometimes even
intermissions. Thus we may suppose that there is a certain
degree of analogy between its operation and that of the
malarious poison, by virtue of which it may perhaps exert a
corrective power over the working of the latter in the blood.
(Vide page 166.) Such an analogy could only exist in the
case of a Catalytic medicine. It is not observed of Quina,
which is employed in intermittents on the Restorative plan.
Arsenic is foreign to the blood, and is in every way a Catalytic
medicine.
In large doses Arsenical preparations act on the stomach
as irritant poisons. Some of them have been used externally
as Caustics, especially in Lupus. But this is a kind of action
that does not concern us now.
The officinal solution of Arsenite of Potash was introduced
into notice by Dr. Fowler, and is the chief preparation of
Arsenic employed. De Valangin's solution contains a Terchloride
of Arsenic, and is of less than half the strength of
the others. Both of them are used in Ague. Some recommend,
in all cases where Arsenic is used, to begin with small
doses, as two drops of Fowler's solution three times a day,
and gradually to increase the quantity; from the idea that
the system will thus be enabled to tolerate the remedy better,
and that irritation of the stomach will be avoided. Mr.
Hunt deprecates this practice, and recommends regular doses
of three to five drops or more. It may be safely continued
during the paroxysm of Ague, which is a plan that is generally
considered to be unadvisable in the case of Quina. The
latter may be given in a very full dose between the paroxysms;
but this cannot be done with Arsenic, for the consequences
would be dangerous. It is best in all cases to give the
Arsenic after a meal, on a full stomach, as then it is less
likely to irritate, not coming directly in contact with the
coats of the stomach, and being diluted by the food during
its absorption.
Arsenic is useful in other intermittent disorders besides
Ague, as in the various kinds of intermittent neuralgia. It
has been given in some varieties of intermittent pulse, which
are not due to organic disease of the heart. Dr. Darwin
cured a case in which the beats of the heart intermitted regularly
once in every three or four times, by the administration
of four drops of a saturated solution of Arsenious acid three
times a day.
The preparations of Arsenic have even been used in some
cases of Gastrodynia with considerable advantage. In these
instances the disorder of the stomach generally assumes an
intermittent form. It has been supposed by some that
Arsenic in such disorders acts directly upon the nerves; but
it appears to counteract all the manifestations of this intermittent
poison, whether local or general, by the same action
in the blood. (Vide page 212.)
Several attempts have been made at different times to discover
a substitute for Arsenic, and a cheaper remedy than
Quinine, for the treatment of Ague. Iron is employed with
advantage in old chronic cases attended with Anæmia; but it
is not of service by counteracting the intermittent, but by
remedying the anæmic condition which co-exists with it.
M. Piorry, in the course of some experiments made at the
Hôpital de la Pitié at Paris, has found common salt in half-ounce
doses to be very efficient. In his opinion it is more
efficacious than Arsenic, and second only to Quinine, in the
cure of this disorder. The suggestion is a valuable one; but
the dose is very bulky, and it would be difficult to prevent it
from causing vomiting in many cases.
Alum is another medicine which has been recommended in
Ague. It also appears to act on the Catalytic plan; but it
has not been often employed.
The compounds of Arsenic are found to exert a curious
antiseptic influence on dead animal tissues. They particularly
prevent decomposition in animal membranes, by virtue
of a combination which Arsenic forms with Gelatine. Liebig
has founded on these facts a theory of the medicinal action of
Arsenic. (Anim. Chem., part i. p. 206.) He supposes that
substances as Arsenic and Mercury may be able to arrest
contagious and other disorders in the system in the same way
that they control putrefaction out of the body. The use of
Salt and Alum in Ague might seem at first sight to countenance
such a hypothesis as applicable to the treatment of this
disease. But we know that Arsenic does not stop all fermentations.
The grain of wheat will germinate, and its starch
be converted into sugar, after it has been steeped in a solution
of Arsenic to protect it from vermin. And Gelatine,
for which Arsenic has an affinity, has not been proved to exist
in healthy blood.
The compounds of Mercury, the operation of which in
Syphilis is sought to be explained on these grounds, are not
nearly so antiseptic as many other minerals. If this theory
were correct, then all Catalytic medicines, and all antiseptic
substances, should be of equal efficacy in all morbid processes.
But this is far from being the case. Many substances which
are distinguished for their antiseptic powers are found to have
no influence whatever on the progress of these disorders. Are
Acetic acid and Creosote of any use in Ague? Does Alcohol
prevent the drunkard from contracting Syphilis? And if
Arsenic, Alum, and common salt, acted solely by arresting
fermentation, how is it that they have no control over the
supposed fermentations of Syphilis and other diseases? The
explanation required must needs be more specific and particular.
Ord. VII. Anticonvulsives.
I have already sought to show that the metallic substances
which are used in the treatment of spasmodic disorders act in
the blood, and tend to establish in it a set of actions of a
peculiar kind. I am able to add little respecting the rationale
of their action to that which I have said of the
operation of Catalytic medicines in general. It is certainly
very mysterious; and it is perhaps mainly on this account
that some have been induced altogether to deny it. But a
denial so grounded is disingenuous and wrong, for we must
often be content to know and to receive many things that we
do not understand.
Perhaps the most evident and characteristic of these agencies
is that of Nitrate of Silver in the cure of Epilepsy. The Acetate
of Lead, and the Ammonio-sulphate of Copper, have been
used with advantage in the same disorder. Dr. Babington
strongly recommends the Sulphate of Zinc, given at first in
small doses, and then gradually increased, so that it may not
produce vomiting.
In the treatment of Chorea, Arsenic is highly esteemed
and recommended by Dr. Pereira.
In Hysteria these medicines are all probably more or less
applicable; but on account of the obstinate and multiform
nature of this disease, their use in it is less obvious than in
Epilepsy and Chorea. Hysteria, too, is more under the influence
of Nerve-medicines than are the other two diseases.
The great objection to Silver, in whatever form given, is
that its salts are liable to be reduced in the system, and it
thus tends to produce a permanent discoloration of the skin,
either browning it or communicating to it a dull leaden hue.
This naturally constitutes a strong ground of objection with
the unfortunate patient, who would often prefer to be left
alone with his fits than to be turned blue for life.
M. Georget supposes that the advocates for the use of
Nitrate of Silver in Epilepsy employ it on the principle
of counter-irritation, saying that they attempt to cure a diseased
brain by cauterizing the stomach. (Physiology of the
Nerv. System, vol. ii. p. 401.) But I am not aware that any
English therapeutists have adopted this view of its mode of
operation. The dose of the Nitrate of Silver, and the state
of dilution in which it is given, would certainly prevent it
from manifesting any such action. And we should not be
warranted in supposing that any of the medicines of this or
any other order of Catalytic remedies could act in so direct
and so easy a way as that, even if it were thus possible.
Some have supposed that Nitrate of Silver cures Epilepsy
by diminishing an irritable condition of the stomach. But
it is observed by Dr. Pereira that the existence of this irritability
in all cases of Epilepsy is a mere assumption. The
solution of this salt exerts, according to its strength, an
astringent or caustic action on all mucous surfaces, and thus
improves their condition when they are relaxed, inflamed,
irritable, or ulcerated. The occasional benefit which follows
the administration of the preparations of Silver in Gastrodynia
may be referred to an action of this kind. The action
of Arsenic in some intermittent varieties of this painful affection
has already been mentioned, and is explained in another
way. Caustic substances probably act locally in these cases;
but Arsenious preparations exert an Antiperiodic influence in
the blood generally.
Tetanus is by far the most incurable of these convulsive
disorders. Arsenic and other medicines of this order have
been recommended in the treatment; but although some cases
appear to be partly connected in their first origin with a certain
condition of the blood, this disease is very little under
the influence of blood medicines, or indeed of any medicines
at all.
Ord. VIII. Antisquamics.
Skin diseases are both caused and cured in a variety of
ways. Some are produced by external influences. They may
be brought on by mere irritation, as certain kinds of Eczema
and Herpes, and are then to be treated with soothing unguents
or cool lotions. Or they may even be connected with
some external organization, of a vegetable or animal kind, as
Porrigo and Favus are traceable to a parasitic fungus, and
Scabies is accompanied by the development of a species of
Acarus. Others are due to some wrong in the digestive
process, or to a plethoric condition of the system. Urticaria
is an example of the former, Acne of the latter. They may
generally be treated most effectually by the exhibition of
salines and rhubarb.
A third class of skin diseases are due to the existence in
the blood of certain poisons or peculiar morbid conditions.
The eruption may constitute one only among many symptoms
of the action of this poison, or it may be the chief or
only symptom. The former is the case in Syphilis and the
Eruptive fevers. It is with the latter kind that we are now
concerned.
There are two modes by which we may get rid of the poison
that causes the eruption—Elimination and Counteraction.
The first may sometimes be effected by the use of Purgatives,
Sudorifics, or Diuretics.
But I have classed in this last order of Catalytic blood-medicines
some remedies that have proved useful in counteracting
the causes of these diseases. The eruptive disorders
alluded to are all connected together both in their symptoms
and treatment; but because the squamous diseases, Lepra and
Psoriasis, are the most characteristically under the influence of
these remedies, the latter have been named Antisquamics.
Arsenious acid, as contained in Fowler's solution, a remedy
already twice named among Catalytics, is also the most
powerful of these Antisquamic agents. Mr. Hunt considers
it to be a specific for all skin diseases that are not syphilitic
in their origin. Besides Lepra and Psoriasis, it is found
useful in Eczema, Impetigo, and Lupus. In the last disorder
it has been used both externally and internally, seeming
to be in both cases specific in its action. Thus we find in
these skin diseases another special antagonism for this extraordinary
medicine, which has already been shown to be of
considerable efficacy both in periodic and convulsive disorders.
Pitch or Tar is another remedy which seems to be capable
of counteracting the scaly disorders. It may be either
applied externally, or given internally in doses of 10 to 20
grains. It has been recommended for employment in some of
the other skin diseases, but its advantage in them is not so
obvious. When it is applied to the skin, some one of its principles
is probably absorbed. Pitch, as a remedy for Lepra, is
comparatively of recent introduction, but its efficacy has already
been very widely acknowledged.
Tincture of Cantharides and Acetate of Potash, both diuretics,
have been employed in Lepra to eliminate the materies
morbi from the blood into the urine, and have sometimes appeared
to succeed in so doing. But in this, as in many other
cases, counteraction is both easier and more certain than
elimination. The system itself naturally attempts this elimination,
and when it finds it impossible, we often gain nothing
by urging it.
I need scarcely say that these remedies are applicable only
in simple Lepra and Psoriasis, and not in the syphilitic forms
of those eruptions, which are treated best by Mercury, or by
other medicines of the second order of Catalytics. These
Syphilitic eruptions are distinguished by a coppery or a livid-grayish
colour, and by the absence of itching.
Sulphur has been used with benefit in Eczema, Impetigo,
and Lepra. It may be administered externally in the form
of fumigation or ointment, or internally in combination with
an alkali or with Iodine. In the case of Eczema and Impetigo,
the fumigation and internal administration are preferable,
as the ointment is apt to increase the existing irritation.
In the cure of Lepra the mineral waters of Harrowgate and
other places, containing Sulphuretted Hydrogen gas, have been
much recommended. Thus we have in Sulphur a third Antisquamic
medicine. It is more or less useful in all non-syphilitic
cutaneous disorders. Dr. Burgess has found sulphur
ointment and fumigations to be very useful in Psoriasis
palmaris. (On Eruptions of the Face, etc., p. 229.)
Though Sulphur seems to act specifically in the treatment
of these disorders, there is another disease of a similar kind
which it has been supposed to cure by a mere external agency.
This is Scabies. Some have fancied that even here it acted
specifically, and that this also was a blood-disease. But
Scabies has long been attributed to an external cause, an
insect, or, more correctly, an arachnid, which, by burrowing
in the skin, is thought to produce the vesicular eruption. The
Acarus Scabiei, or Itch insect, was discovered in 1179 by Abenzoar,
the Arabian. In 1687 Dr. Giovanni Bonomo wrote a
full account of it in a letter to Redi of Florence. It is supposed
that Sulphur ointments and Sulphur fumigations have a
direct external action in causing the death of this Acarus, by
the bodily transmission of which from one person to another
the contagious nature of the disease is accounted for.
Dr. Billing considers that the confirmation of this discovery
has given the death-blow to an idea which will probably last
as long as medicine; viz., that certain remedies exert a special
influence in the cure of particular diseases. (Principles of
Medicine, p. 75.) But we must not deny the existence of
special agents, simply because we cannot understand their
operation; for it is apparent in too many instances. And
from the circumstance that Sulphur has proved beneficial
when given internally in Scabies, as well as the fact that this
disease has often an idiopathic origin, I am still disposed to
doubt the value of the inference which is drawn from the
discovery of the Acarus, and inclined to believe that Sulphur
may exert an action of a specific kind in this disease as well
as in the others.
Some other internal remedies, and many other external
applications, have been used in Skin diseases; but these that
I have mentioned are the only ones that appear to exert
something of a special action in all cases. Arsenic is perhaps
the most universal in its application. It often happens that
when this remedy entirely fails, the eruption is connected
with a constitutional taint of Syphilis. When there is a
suspicion of this, such a remedy as Donovan's solution, containing
both Arsenic and Mercury, is peculiarly applicable,
because capable of acting in a double way. This medicine
also contains Iodine; and either this preparation, or the
Iodide of Potassium, should be prescribed when the skin disease
appears to be connected with a strumous diathesis.
As soon as the course of Arsenic is found to produce swelling
of the face, or irritation of the conjunctivæ, symptoms
which denote the saturation of the system with the remedy,
its administration should be suspended for a while.
We have now concluded the subject of Hæmatic medicines.
I have said that this class has been very generally neglected
and overlooked by writers on the subject. For this reason,
and because there are some ideas respecting their action which
I have thought it worth while to work out and to investigate
at some length, I have devoted more space to its elaboration
than I shall be able to spare for either of the remaining
classes, in the consideration of which we are not likely to encounter
so many interesting and debateable points.
1. That of these, some, called Stimulants, act so as to exalt
nervous force in general or in particular.
2. That others, called Narcotics, act so as first to exalt
nervous force, and then to depress it; and have also a
special influence on the intellectual part of the brain.
3. That others again, called Sedatives, act so as to depress
nervous force, in general or in particular.
Having investigated at some length the action of Blood-medicines,
we now commence the consideration of another
class of remedies, which differ very widely from the last in
their mode of operation.
The action of Hæmatics is slow, but more or less durable,
because it is evidenced in the blood; and a change in the
blood produced by this action continues for a longer or a
shorter time.
The action of Neurotics, or Nerve-medicines, is rapid; but
it is transient, and is soon over. A Neurotic medicine does
not cause any change in the blood; and it cannot remain in
it, but soon passes out. It acts by contact with nerve, apparently
producing no lasting change even in nerve-fibre;
and as the cause of the action cannot remain, the effect also
soon passes away. Whereas Hæmatics, durable agents in the
blood, are used to counteract the causes of inveterate and
chronic disorders; these Neurotics, which produce a transitory,
but more or less forcible impression on the nervous system,
are employed to rouse it when torpid, or to depress it
when over-excited. Rarely of use in chronic blood-disorders,
they are given mostly in the temporary emergencies of acute
diseases. But it is obvious that even a temporary agent may
prove of permanent efficacy by remedying a temporary emergency.
It was feasible to attempt some explanation of the actions
of medicines in the blood, occasionally more or less analogous
to known chemical influences. But the agency of nerve-medicines
is of a far more incomprehensible kind. When we
consider that little or nothing is known, or can be known,
about the ultimate causes of sensation, or motion, or nervous
excitement, there is no need for wonder that we find ourselves
at a loss to explain the operation of medicines that influence
these conditions.
Thus I must chiefly limit my remarks on Neurotics to
defining what their action is, finding it impossible to state
with certainty how they act. And the field of inquiry being
so limited, it follows that there is much less to be said about
them than had to be said of Hæmatics.
Nearly all the powerful poisons that act after passage into
the blood, belong to this class. Their action in most points
of view is such as completely to exceed our means of comprehension.
Sudden death may be produced by it. But there is no
apparent cause for this. We find no erosion or perforation
of the coats of the stomach or intestines; no mechanical disorganization
of the tissues, or chemical change in them; no
hæmorrhage, or vascular disease; no rupture of nerve-fibres.
Whence, then, could death have arisen? How could the mere
presence of a few atoms in the blood,—half a grain, one-twentieth,
or even one-fiftieth of a grain—how could this
apparently contemptible influence have produced so essential
a derangement of the vital functions as to stop them altogether?
It is impossible to answer.
The action of such remedies in the sudden causation or
alleviation of nervous symptoms, when applied in the cure of
disease, is equally wonderful. How are we to account for
their different actions on different nerves? How is it that
Opium contracts the pupil, and Belladonna dilates it?—that
Digitalis affects the heart, and Stramonium the respiration?—that
Prussic acid will cause convulsions, and Hyoscyamus
delirium? In what way are these various operations brought
to pass? It is impossible to answer.
Though it is, I say, quite impossible to frame for any one
of these questions a certain or satisfactory reply, on account
of the manifest insufficiency of our acquaintance with the
details of such actions as these, yet I must now venture to
repeat an idea which I have already referred to at the commencement
of this Essay (p. 46,) and state my belief in the
bare possibility of the operations of Neurotic agents being
explicable upon mechanical grounds. It is generally believed
among scientific men that each particle of a compound body
is made up of a number of indivisible atoms, each of which
is inconceivably minute in size. And as these compound
bodies have each a peculiar chemical constitution, so must
each of their ultimate parts be composed of a peculiar
arrangement of simpler atoms, and thus have a certain shape
of its own more or less different from the shape of every
other compound atom. Both the substance of a nerve, and
the active part of a nerve-medicine, consist of a number of
definite compound atoms. And it is possible that the atom
of a stimulant medicine may be of such a shape as that it
shall be unable to coincide with, or to fit into, the series of
atoms forming the sensitive surface of the nerve, and thus
irritate this when brought into contact with it; and that the
compound atoms of a sedative may so arrange with these
nerve particles as to fit among and extinguish their salient
points, and annihilate their natural sensibility. We learn
from the phenomena of the senses that the nerves are very
much under the influence of mechanical impulses of all kinds,
and particularly minute and inappreciable impulses of this
description. Another fact which gives additional credibility
to such an idea is, that those Neurotic substances which are
chemically alike are in general alike also in their influence
on nerve.
The particular way in which nerve-medicines affect different
parts of the nervous system might perhaps be explained by
supposing minute chemical differences in the composition of
the atoms of which those parts are constructed, sufficient to
alter their relations to the atoms of certain remedies. If we
adopt the Atomic theory, we must perceive that no two chemical
bodies can be precisely alike in the shapes of their
particles. This various dissimilarity might throw some light
upon the many shades of distinction between the operations
of Neurotic medicines on different parts. Thus, as a general
rule, both Morphia and Atropia are paralyzers of motor
nerves. But they do not act alike on the Ciliary nerves by
which the motions of the Iris are controlled. We may suppose
that there is a certain chemical peculiarity in the particles
of these nerves, by which they are enabled to coincide
with the atoms of Atropia, and are thus blunted and paralyzed
by them; but are, on the contrary, stimulated and excited
by the atoms of Morphia, which have the contrary action,
because unable, on account of their relative shape, to dove-tail
with these atoms.
This idea is, as I have said, purely conjectural and fictitious,
and is indeed likely to remain so; for the thing is not by its
nature susceptible of proof, nor is it even possible to inquire
into it. And I have only thought it worth while to explain
it at length because it is desirable that every statement which
is made, however improbable and unworthy of credence it
may seem, should at least be placed in as clear a light as
possible.
The action of a Neurotic is readily distinguished from that
of Hæmatic medicines by the fact of its exerting a rapid and
well marked influence of some kind on the nervous system.
As it is impossible that the medicines contained in this class
should remain in the blood, they therefore pass out of the
blood through the glands, and in so doing generally act as
Eliminatives. This, their secondary action, will be subsequently
considered. It is generally of less importance than
their action on nerve; with the exception of some which, as
volatile oils and resins, exert a very feeble Neurotic action,
but are comparatively powerful as Eliminatives. In this case
the secondary action becomes the more important of the two.
The most dangerous symptoms of disease are evidenced in
the nervous system. Neurotics are employed to control these
symptoms as they arise, but Hæmatics are used to combat the
cause of the disorder. As to their relative efficacy, there is
an advantage and a disadvantage on each side. On the one
hand, nerve-medicines are more numerous and more powerful
than blood-medicines, and thus in the control of symptoms
they are wielded with more immediate certainty than the
others in the counteraction of diseases. On the other hand,
the symptom that is dreaded is only relieved for a time
by the Neurotic remedy, while the morbid condition that
caused it continues, and will perhaps cause it again; but
when a disorder is remedied by the employment of Hæmatic
medicines, it is more or less permanently cured and put an
end to.
In the above Proposition I have endeavoured to state as
much as we know with certainty of the action of Neurotics.
To this certainty I have already ventured to add a surmise,
on which no certain reliance can be placed. But even if the
theory of the action by atomic shapes should be rejected as
improbable, because affording too easy an explanation of a
naturally inscrutable operation, it would still seem likely that
these medicines may take effect by exerting some minute and
imperceptible influence on nerve-fibre, or producing in it some
inappreciable disorganization or change, which has the effect
of altering the natural performance of its functions. The
effect of mechanical concussion or shock, which may produce
death by minutely disarranging the particles of the nervous
centres, presents an obvious analogy to the sudden and remarkable
action of some nerve-poisons.
Having offered these vague suggestions as to the ultimate
modus operandi of Neurotics, I will now proceed to divide the
Proposition in which their more obvious action has been
stated into a number of minor propositions. These apply to
the whole class. The three divisions will be afterwards
shortly considered separately.
m. p. 1.—That Neurotics are medicines which pass into the blood.
m. p. 2.—That their action is evidenced by a change in one or more of those functions which are attributed to the nervous system.
m. p. 3.—That it is necessary that they should pass from the blood to that part of the nervous system which is influenced by them.
m. p. 4.—That they are of use in an over-excited or depressed state of the nervous system.
m. p. 5.—That they are transitory in action, and cannot remain in the blood.
Some space and labour was required in the proof of the
minor propositions relating to Hæmatics, for among them were
included some things that are not universally acknowledged;
but the above account of the action of Neurotics concerns
matters that are very generally admitted, and will not occupy
us nearly so long in its discussion.
In the first place it is affirmed that Neurotic medicines
pass into the blood. In the consideration of Prop. II., it was
shown that all of them,—whether vegetable alkaloids, volatile
oils, resins, or mineral substances,—were more or less
capable of being absorbed. That they do pass into the blood
is proved by the fact that many of them have been detected
there, as well as found in the secretions into which they must
have entered from the blood. Ammonia, Hydrocyanic acid,
Antimony, Assafœtida, Turpentine, Alcohol, and Camphor,—all
of which are Neurotic agents,—have been chemically
detected in the blood by Tiedemann and Gmelin. A still
larger number have been discovered in the urine by Wöhler,
particularly of volatile oils and odorous principles. The active
principles of Opium, Belladonna, Stramonium, and Henbane,
have been detected in the same secretion by others.
Thus Neurotics pass into the blood. That they act after
this absorption, and not by contact with the mucous surface,
was proved in the consideration of Prop. I.
The second minor proposition is borne out even by the
names by which the recognised action of these medicines is
distinguished. Considered as a class, they have no action on
the blood, but their influence is quickly and obviously exerted
on the nervous system, or on the vital functions which are
universally attributed to that part of the animal frame. Stimulants
are so called because they are found by experience
to exalt nervous force; Sedatives, because they depress it.
Thus Ammonia is given to prevent Syncope, caused by a
weakness or failure in power of the nerves of the heart; and
Aconite is prescribed to relieve pain caused by an over-excitement
of the sensory nerves. Though in these examples
Ammonia acts on the centre, and Aconite on the peripheral
nerves, yet they are both capable of exalting or of depressing
nervous force in general. But neither Stimulants nor Sedatives,
as defined by me, exert any marked influence on the
intellectual part of the brain. They do not affect the phenomena
of mind, or of the four special senses which are
immediately associated with it. This influence is confined to
the intermediate division of Nerve-medicines, called Narcotics.
Their general action is evidenced by a short or long
primary stimulation,—and a subsequent depression of nervous
force, which is also of variable intensity. At the same time
they affect the mind in various ways; exciting it, confusing
it or lulling it. Opium and Alcohol are examples of Narcotics.
These distinctions are in most cases obvious and well
defined.[42]
The third minor proposition repeats the rule of local access,
which has already been enforced in treating of the fifth proposition.
It was not necessary to maintain this in the case
of medicines acting on the blood; but Neurotic agents must
be shown to operate locally on the various nervous organs.
I have only to repeat the arguments which were urged before.
It is proved that the action of nerve-medicines cannot be
propagated by nervous connexion, but that passage in the
circulation is necessary; that the course of the latter is sufficiently
rapid to account even for the action of Hydrocyanic
acid; and that, however near a medicine be introduced to a
nervous organ, it does not affect it unless it be allowed to
reach it. The nerves are not naturally constituted for the
conduction of medicinal impressions, but only for the passage
of impulses of volition, sensation, or emotion. And this
evidently forms a powerful safeguard to the system against
the effects of a poison. The assertion is further maintained
by the fact that the action of a Neurotic, when applied topically
to the part which it tends to influence, is the same as
that which is exerted by it on the same part after absorption.
And lastly, some nerve-medicines have actually been found
after death in the substance of those nerves and centres which
had been affected by them during life.
The use of these medicines in the treatment of disease is
defined in the fourth minor proposition. They have no influence
in the blood. They are not employed in slow or
long continuing diseases. Their applications depend on their
known physiological tendencies, already stated. Abnormal
deviations from the proper functions of the nervous system
are rectified by means of the influence which they exert over
the nervous organs.
When the powers of life are sinking, the nervous force on
which life depends may perhaps be roused by a strong
Stimulant, and maintained by its repetition. Sometimes
the emergency may be thus postponed, and the danger
escaped.
In violent inflammations and fevers, when the action of the
heart is so violent, and the nerves that control it so excited,
as to place life in peril, we may do good by the administration
of a Sedative, such as Antimony or Digitalis, by which the
nervous force may be reduced to its proper level.
Narcotics are used in various cases, to cause sleep, or to
quiet mental irritability. Both these and Sedatives are employed
to alleviate the different kinds of pain.
Neurotics are thus applied to various symptoms, and to
many disorders. Their different modes of action will be detailed
more at length presently. It must be remembered
that all these actions, powerful though they may be, are
transitory. The effect produced on the nerve is not a lasting
one, and no essential change in the blood is effected by true
Neurotics. They are not natural elements of this fluid, but
must quickly pass out of it; and they having thus left it,
their action also is over. Thus the truth of the fifth minor
proposition is plain.
I will now attempt to give a brief but distinct account of
the three divisions into which I have divided this class of
medicines.
Stimulants are medicines which pass from the blood to the
nerves or nerve-centres, and act on them so as to exalt nervous
force, in general or in particular. That is, they may
extend their operation more or less to the whole nervous system,
having a general tendency to communicate nervous
energy; or they may confine their action to particular departments
of this system, having no manifest influence on
other parts. On referring to the arrangement at the commencement
of the Essay, it will be seen that Stimulants are
subdivided, according to whether their action is thus extended
or confined.
STIMULANTIA.
Ord. 1. Stimulantia generalia.
Ord. 2. Stimulantia specifica.
The first order includes all the medicines that are commonly
understood to be Stimulants. But as the remedies of
the second order obviously exalt nervous force, the term applied
to the others on that ground could not consistently be
withheld from them, although their action is more limited
and local in its nature, being confined to a certain part of the
body, and to certain nerves. The same remark may be made
of the order of Special Sedatives, which will soon have to be
considered.
Ord. I. General Stimulants.
(Mineral substances.—Ammonia and its Carbonates. Phosphorus.
Animal substances.—Musk, and Castor.
Vegetables containing volatile oils.—The aromatic Labiatæ,
Compositæ, and Umbelliferæ. Cloves and Nutmeg. Cinnamon,
Cassia, Sassafras. Rue, Barosma. The Aurantiaceæ.
Canella. Valerian. Mustard. Cajeput and Pimenta.
Hops. Juniper, Turpentine. Cardamom. Onion.
Vegetables containing acrid principles.—Senega. Horseradish.
Serpentary. Cascarilla. Pepper. Contrajerva.
Ginger. Capsicum. Mezereon.
Resinous substances.—Guaiacum. Mastich, Olibanum, Myrrh,
Elemi. Copaiba. Peru, Tolu. Assafœtida, Ammoniacum,
Galbanum. Benzoin, Storax. Pine resin.)
This list of General Stimulants is long, but it might even
be further extended. The majority are produced by the vegetable
kingdom. The acrid principles to which some owe their
power are intermediate in nature between volatile oils and
resins. Some of them are volatile, like the former; others
fixed, like the latter. Some of the resinous products contain
also a volatile oil. The principles of Capsicum and Mezereon
are very similar in their chemical nature to the true resins.
(Vide page 85.)
These remedies differ very much in power, but their influence
is the same in character. They exalt nervous force in
general. They seem to act on the whole nervous system;
but their most obvious action is to increase the force and
frequency of the pulse, and to invigorate the circulation.
They are not, for the most part, very powerful medicines;
and their action is seldom so violent as to be succeeded by
much reaction. They improve digestion for a time, by a
stimulation of the sympathetic nerves of the stomach and
other viscera. In large doses they are irritants, and may
impair the digestive powers, and cause headache. Though
possessing no marked stimulant power over the function of
mind, like that of the Inebriant Narcotics, yet they certainly
exalt the activity of the brain, along with the other nervous
forces.
Dr. Pereira classes the majority of Stimulants among
Ganglionics, considering that they only act on parts supplied
by the sympathetic system of nerves. But this view of their
operation appears to me to be too limited; for all of them
seem to have a certain action on the brain.
Thus Ammonia is used in Syncope, a state which no doubt
depends upon a shock received by the brain. And there are
several things which show that it relieves this state more by
stimulating the brain than by merely rousing the heart and
vascular system. It is found to be most effectual when inhaled
through the nose; by which means it could easily pass
at once into the cerebral circulation. Dr. Pereira thinks that
when administered in the liquid form it can only pass into
the blood as a salt, being neutralized by the stomach-acid.
In this case it could only act before absorption. But it is
probable that it is too diffusible and too rapidly absorbed to
be entirely so neutralized; and besides, its operation when
inhaled is the same as when ingested, which seems to point
to an agency after absorption in the latter case. For when
inhaled, it must be absorbed in the free state. And to suppose
that it acts by stimulating the nerves of the stomach
only, is to receive a thing for which we find no parallel in the
action of medicines. (Vide Prop. I.)
Ammonia has been used with advantage in the prevention
of Epileptic fits, being given just before their expected occurrence.
It could hardly be of use in this disorder unless it
affected the brain.
Other General Stimulants manifest this action on the brain
to a greater or less degree.
Phosphorus is a Stimulant. In small doses it quickens the
pulse. It somewhat heightens the mental activity. It is
said also to have an aphrodisiac operation, due to its powers
as a cerebral excitor. Volatile oils possess a certain influence
over the functions of the brain, as well as those of
the organic nerves. Cajeput oil has been used in Hysteria;
employed to control various spasmodic movements; and
administered in Typhoid fevers and Asiatic Cholera, to communicate
nervous power. The fetid gum resins are well
known as Antispasmodics. The spasms which these medicines
relieve are due to a fault in the nervous polarity, commencing
generally in the brain or nerve-centres,—and are
more or less subdued by general stimulators of the nervous
functions. Copaiba, an oleo-resin, may cause a general febrile
condition, accompanied with headache,—when given in large
doses.
So obvious is the cerebral power of some volatile oils, that
Turpentine, in large doses, has been known to produce inebriation.
It is not generally used for its Neurotic powers,
but as a Purgative or a Diuretic; or else it might have been
classed among Inebriant Narcotics. I have enumerated it
above among volatile oils. It may be regarded as transitional
between true Stimulants and Narcotics.
Ergot of Rye is another medicine which has a double action. It
is used as a Special Stimulant to the Uterus; but it
is also a Narcotic to the brain.
Most General Stimulants are without any marked influence
on the mind; but stimulate the organic and merely animal
function of the brain, and of the Sympathetic nerve throughout
the system.
Concluding that General Stimulants have all more or less
the power of exalting nervous force in general, we have still
to consider some other questions relating to their action.
It is maintained by some that Stimulants have simply the
power of calling forth the nervous force which already exists
in the system, and that they cannot create any more in addition
to this. But if this were the case, then the reaction, or
subsequent failure of nervous power, ought to be exactly
equivalent to the first temporary increase of that power;
assuming this increase to have been simply abstracted from
the natural resources. But we do not find it to be so. The
reaction from the effect of a Stimulant is always very slight,
and often quite imperceptible.
And there seems to be no à priori reason why we should
not actually cause nervous force to be generated. We know
that a galvanic current, or even a mechanical cause, may induce
it to be suddenly and powerfully manifested. I believe
that a Stimulant is able actually to produce nervous action;
perhaps by an irritative operation upon nerve-fibre. So by
continually repeating the dose of a Stimulant, as Ammonia or
Brandy, it is possible to maintain the circulation and nervous
energy at a certain level, without the occurrence of any reaction
for a considerable period.
But we must take care not to confound nervous force with
vital force. The former may be very much increased, as in
high inflammatory fever, without a corresponding increase of
the latter. The advantage of a stimulant is regulated by this
rule. When there is a failure in vital energy, no Stimulant
will serve to prolong life, for it cannot communicate fresh
vital power. But there may be no such failure of vital
energy, and yet a sudden or accidental deficiency of nervous
force may serve to peril the continuance of health, or even
the tenure of life. For a certain degree of this nervous force
is necessary both for life and health. When it is diminished,
all the functions must suffer; when it fails entirely, the circulation
must stop, and death ensues. It is in these cases that
a Stimulant medicine is appropriate. It does not do good by
communicating vital energy, but by remedying the want of
nervous action, by which want the manifestation of the vital
energy is subdued. This must always be borne in mind when
the applicability of Stimulants is under consideration.
Some writers have complicated the subject by classing as
Stimulants all medicines which tend, directly or indirectly, to
communicate vital strength; as Tonics, and remedies which
counteract morbid depressing causes. This is in direct contradiction
to the rule given above. True Stimulants are only
of use by counteracting that failure of nervous force which
hinders the manifestation of the vital strength which is stored
up somewhere in the system. For I have just observed, that
to exalt nervous force is not necessarily to exalt vital force,
but that any thing which tends to destroy the former must at
length repress and extinguish the latter.
The above considerations apply to the action of these Stimulants
on the powers of the system generally. But they
may act locally. Thus in moderate doses they promote
digestion, by acting on the nerves of the stomach and intestinal
canal. They increase most of the secretions in passing
through the glands in the blood. In both cases they exalt
nervous force; but in the latter case their action is of a particular
nature, and will be treated of when they are considered
under the title of Eliminative medicines.
To impress the system generally, Stimulants are used when
there is a failure of nervous force on account of some sudden
and acute disorder, without any material undermining of the
vital energies. In long chronic cases, where there is real and
manifest vital debility, Tonics or blood-medicines are required.
But in such a case as Syncope, or stoppage of the heart on
account of a sudden nervous shock, Stimulants are particularly
appropriate; also in the latter stage of Typhoid fever, or of
asthenic Pneumonia, or of Cholera, where the existence of life
is endangered by a great loss of nervous power. In spasmodic
diseases, as Hysteria, where the health is deteriorated
on account of a derangement of the nervous functions, Stimulants
may be of use.
Such then appears to be the modus operandi, and such are
the chief applications, of the remedies belonging to the order
of General Stimulants. Those of the next order exert an
action of the same kind, but their field of operation is on a
more confined scale.
Ord. II. Special Stimulants.
(Strychnia; Brucia; Toxicodendron; Ergot of Rye; Borax; Rue.)
These are medicines which pass from the blood to the nerves
or nerve-centres, and act so as to exalt the energy of particular
nerves or sets of nerves. They do not affect the whole
nervous system, but they operate on one set of nerves in the
same way that General Stimulants operate on all, though
usually with greater energy.
The causes of such a localized action are hid in obscurity;
but it has already been hinted that they may perhaps be
partly accounted for by the differences in chemical or mechanical
structure existing between different parts of the
nervous system.
Strychnia, the alkaloid and chief active principle of Nux
Vomica, acts as a Special Stimulant, chiefly to the spinal cord
and the nerves that proceed from it. Its operation is mainly
exerted upon the motor branches. Thus in large doses it
causes a spasmodic and powerful contraction of the muscles
of the trunk, and may even produce death by rendering respiration
impossible. Its action is propagated from a motor
nerve to a muscle, and is kept up for some time. In small
doses it is useful in certain cases of paralysis. Two things
are necessary in order that it may act efficiently. The muscles
of the part must be whole and sound; for if destroyed by
excessive atrophy or fatty degeneration, they cannot be roused
by any stimulus. The nerve, too, and the centre from which
it originates, must be sound, or else the medicinal impulse
cannot be conducted along it. These two conditions can
only concur in paralysis from disuse, i.e. when the incapacity
to move a limb depends merely upon its having long
been in a state of inactivity, but when the lesion of the centre
which caused the paralysis has at length sufficiently healed,
and the nerve is now in a fit state to conduct a motor
impulse.
Strychnia has no operation on the intellectual functions;
neither does it act upon the sympathetic nerves of the heart
and arteries, so as to quicken the pulse like ordinary stimulants.
It exalts sensibility as well as irritability, but not so
powerfully. It is a special Stimulant to the motor and
sensory nerves throughout the body. Acting upon the spinal
cord, it tends thus to exalt reflex action, which is derived from
that centre. In small doses it appears to promote digestion,
and may perhaps act upon the ganglionic nerves supplied to
the stomach.
Brucia, which is the other alkaloid of Nux Vomica,—and
the leaves of the Rhus Toxicodendron,—resemble Strychnia
in their action, but are less powerful.
Ergot of Rye is a stimulant to the muscular nerves of the
Uterus of the female, but to no other nerves in any marked
degree. Borax and Rue possess a similar action, but are
not so efficient.
When labour is retarded on account of an atony or debility
of the Uterine muscle, and when also there is no
obstruction or danger which can result from bringing on
contraction, Ergot supplies us with a ready and effectual
means of doing this. It is also efficacious in cases of uterine
hæmorrhage, because the open mouths of the bleeding veins
in the wall of the uterus are closed by the contraction which
it causes.
When given in an over-dose, Ergot has a dangerous action
on the brain, producing at some times narcotism, at other
times syncope. But this is not the effect for which it is employed,
and is altogether distinct from its operation as a
Special Stimulant, which is exerted only upon the ganglionic
nerves of the muscular uterus. In small doses it produces no
other effect than this.
Like the other medicines of this order, Ergot is not an
excitor of the heart and circulation. Its stimulant action is
strictly local in its nature.
This, the second division of Neurotic medicines, is in one
sense intermediate between the other two divisions, but in
another sense different from both of them. Narcotics are
defined to be medicines which pass from the blood to the
nerves or nerve-centres; which act so as first to exalt nervous
force, and then to depress it; and have also a special action
on the intellectual part of the brain.
This primary exaltation of nervous force is produced by
some to a very considerable extent, but by others very slightly.
Of the three orders into which I have divided Narcotics, which
are named from their respective actions upon the brain, Inebriants
cause most, and Deliriants least, of this primary
stimulation. In the second place, Narcotics depress nervous
influence. This depression is not in a direct, but in an inverse
ratio to the primary stimulation. The less the one, the greater
the other. Thus the depression cannot be considered as the
mere re-action from the stimulation, as supposed by Dr. Brown,
for then there would be a direct relation between the two
effects. But we find that the exhilarating action of Alcohol
may often be followed by no manifest depression; and that
Belladonna, which scarcely stimulates at all, exerts a very
sensible depressing influence.
Regarded simply in their action on nervous force generally,
the medicines of the first order of Narcotics would approach
very nearly to Stimulants, and those of the third order to
Sedatives. But Narcotics have all a power which is possessed
by neither of the other divisions.
They influence the intellectual functions, i.e. the mind,
and the physical ties by which mind is connected with matter.
These physical ties are,—the functions of volition and sensation,
by which the mind is connected with the body, moving
it or feeling it; and the five senses, by which the mind, through
the body, is connected with external things. These intellectual
properties, the centre of which is the brain, are more or less
affected by Narcotic medicines. The first action of the latter
is, to exalt these functions, just as they first exalt nervous
force in general. The degree of this exaltation varies, as in
the former case. Inebriants stimulate the mind to a considerable
degree; Soporifics less; and Deliriants possess least
of this primary exciting power. But it is in their secondary
action on the mind that we find the most characteristic difference
between them.
On referring to the arrangement, it will be seen that I
have divided Narcotics into the three orders to which I have
already referred by name, and which are thus designated in
Latin:
Narcotica.
Ord. 1. Inebriantia.
Ord. 2. Somnifera.
Ord. 3. Deliriantia.
These Orders are named from the secondary action of these
different Narcotics on the intellectual functions. In the production
of inebriation these functions are impaired and deranged;
in sleep they are lulled or extinguished for a time;
and in delirium they are excited and led astray. The several
actions of these orders will be more minutely described presently,
and the individual medicines of which they are composed
will be shown to agree with the general definition of Narcotics.
Dr. A. Billing considers that Stimulants call forth nervous
force, and Sedatives depress it; and that Narcotics do neither
the one nor the other, but merely impede its communication.
I do not consider this distinction to be quite correct. Narcotics
exert in the first place a stimulant, and in the second
place a sedative action; but these actions have no relation in
degree, for one of them always exceeds the other, as we have
just seen. Thus in the whole effect, either the stimulation
must exceed the depression, or the depression must be greater
than the stimulation. So that in one way or the other the
quality of nervous influence must be altered.
The medicines of the first order of Narcotics resemble Stimulants
so far as this, that they tend altogether to increase
the amount of nervous force. Perhaps Tobacco and Lobelia
are exceptions to this. The medicines of the third order,
and some of those in the second, tend on the whole to diminish
the quantity of nervous force, and are thus akin to Sedatives.
A correct understanding of the differences in action which
exist between the groups of Neurotic medicines is, I think,
very essential to a right application of these remedies in the
treatment of disease.
Ord. I. Inebriantia.
(Alcohol; Wine; Ethers; Chloroform; Camphor; Indian
Hemp; Tobacco; Lobelia.)
The medicines of this order, taking Alcohol as the type,
approach more nearly to Stimulants than any other Narcotics.
When given in small doses, their narcotic operation
may hardly be perceived. They are then exhilarants; slightly
quickening the pulse, and enlivening the mental faculties.
When given in large doses, this stimulating action on the
heart and mental powers occurs first, and is now more intense;
but it is soon succeeded by disturbance and impairment
of the intellectual functions. The secondary depression
of the heart is comparatively feeble, except in the case of
Tobacco and Lobelia, which are exceptional members of this
order.
The disturbance of the mind produced by these medicines
is not of a partial, but of a general character, extending to
all the intellectual functions. It is called Inebriation, or
drunkenness, and may exist in various degrees. The mind
itself is confused and bewildered; volition is impaired, so that
the man staggers in his walk; and the powers of the senses
are disordered or lost. This condition, when carried to an excess,
results in stupefaction, coma, and death. These are
the several degrees of the same action, which is a general impairment
of all the intellectual functions.
Alcohol and the Ethers produce the primary exhilaration
in the greatest degree; Tobacco and Lobelia, in the least.
Though varying in degree, yet, as far as the stage of inebriation,
the effects of these medicines are similar in kind.
Stupefaction constitutes the next stage of the action of
Alcohol, Camphor, Indian Hemp, Ether, and Chloroform.
Camphor and Indian Hemp exert at this period an anodyne
influence; to which also, in the case of Indian Hemp, may
be added a very curious imitation of Catalepsy. Ether and
Chloroform have at this time a peculiar action in extinguishing
the sense of Feeling. With this object they
are commonly administered by inhalation in painful surgical
operations.
The stupefaction produced by the above medicines is not
at all prominent in the case of Tobacco and Lobelia inflata.
Instead of that they both exert a particular sedative action
on the heart and circulation. This is accompanied with
nausea, and with great relaxation of the muscular system, like
that which is produced by Antimony. It may lead to syncope
and death.
Syncope has been known to be suddenly produced in some
cases of the inhalation of Ether and Chloroform. These two
medicines are also muscular relaxers, like Tobacco.
The cases which demand the employment of these medicines,
as also of the other Narcotics and Sedatives, will be
considered at the close of the section treating of Neurotics,
and again when some of them are separately described in the
fourth chapter.
Ord. II. Soporifics.
(Opium. Lactuca. Hops. Nutmegs.)
Opium, which is the chief and only important medicine of
this order, may be considered as the type of Narcotics. It
causes in the first place a slight quickening of the pulse, and
some excitement of the mental faculties. It is named from
its peculiar secondary action on the latter. It produces
drowsiness and sleep.
We have seen that the term intellectual function must be
understood to include not only the mind itself, but also the
powers of volition and sensation, by which the mind is connected
with the body,—and the five senses, by which it is
enabled to appreciate the external world.
Inebriants affect these three in about the same ratio. Ordinarily
they impair the mind, and derange the functions with
which it is connected; but they do not quite extinguish either
volition, sensation, or the special senses. Soporifics differ
from this action in two ways. In sleep the mind may remain
active; but it is left alone, dreaming, and uncontrolled by
physical ties. For the functions of volition and sensation,
and the special senses of Sight, Hearing, Smell, and Taste,
are entirely suspended in perfect sleep. So that while Inebriants
affect similarly both the mind and the natural functions
with which it is connected, Soporifics may leave the first untouched,
but they entirely subdue the latter. The condition
of sleep differs also in another important particular from the
state of inebriation,—as well as from delirium, which we shall
have presently to consider. Sleep is liable to be suddenly
interrupted or suspended by comparatively slight causes, as a
physical shock, or a forcible impression upon one of the
senses which are held in abeyance and subjection. Neither
inebriation nor delirium can be suddenly put an end to in
this way.
Such appears to be the distinction between the operations
of these two orders of medicines.
Pain prevents sleep, because it enforces sensation. Thus a
mere Soporific, if effectual, would prove anodyne, and relieve
pain.
But Opium has an important anodyne action, which is independent
of its power of producing sleep, for it may occur
without the latter. It is by far the best remedy for pain in
the whole catalogue of medicines. It also produces relaxation
of the muscular system, and is thus a powerful antispasmodic.
In excessive dose it produces a marked sedative
effect; causing an imperceptible or irregular pulse, and very
slow breathing, with contraction of the pupil of the eye. It
may kill by apnœa; i.e. by stopping the respiration.
Tobacco resembles Opium in causing contraction of the
pupil, and relaxation of muscular fibre. But it is inebriant,
and not soporific; and its secondary sedative action on the
heart is more powerful than that of Opium. The order of
Deliriants dilate the pupil. Inebriants and Deliriants act on
the glands as Eliminatives, being mostly diuretic. Opium has
a contrary action; it diminishes all the secretions except that
of the skin, which it increases in amount. Most particularly
it diminishes the secretion of the bowels, causing constipation.
At the same time it impairs the appetite and digestive power,
producing often nausea, and coating the tongue. It tends
also to produce a determination of blood to the head.
Lettuce, from which Lactucarium is prepared, resembles
Opium in its action, but is neither so powerful nor so efficient.
Nutmeg and Hops have proved Soporifics when given in large
doses.
The relief of pain, and the production of sleep, are about
the commonest and the most grateful of the offices which fall
to the lot of the physician; and in either case Opium, or one
of its preparations, may be said to be indispensable. But a
certain caution and care must be exercised, even in the administration
of this most useful remedy. (Vide Art. Opium,
Chap. IV.)
Ord. III. Deliriants.
(Hyoscyamus; Belladonna; Stramonium.)
These medicines are all produced by the natural order
Solanaceæ. Of all Narcotics they approach the nearest to
Sedatives. Their only stimulating action is to produce at
the very first a slight and evanescent febrile condition,—a
quick pulse and heat of skin,—which never lasts long, and is
sometimes overlooked.
They are not Soporific. Their action is soon manifested
by an anodyne operation, and a sedative influence on the
heart and circulation. For this double action they are employed
in medicine, being used in painful disorders, fevers,
and inflammations. As anodynes they are not so efficacious
as Opium, but their action is not followed by constipation, or
by a diminution in any of the secretions.
They all dilate the pupil of the eye. Belladonna produces
a peculiar dryness of the throat, and has been known to cause
an erythematous eruption. Stramonium appears especially
to control the respiratory nerves, and is thus used in Asthma,
where there is a spasmodic circular contraction of the smaller
bronchial tubes. Lobelia, a medicine of the first order, possesses
a somewhat similar power. The action of the remedies
of this third order of Narcotics is distinguished by the production
of delirium when they are given in large doses.
Let us again assume the threefold division of the mental
functions, to which allusion has already been made. Inebriants
impair equally the mind, volition, and the five senses.
Soporifics extinguish for awhile both volition and the senses,
but may leave the mind alone. In delirium these functions
are not thus impaired and held in subjection, but they are
excited and led astray. The mind is occupied intently upon
imaginary fancies; unreal objects and hallucinations are presented
to the senses. So that Deliriants, in this peculiar
phase of their action, tend to excite the mind and the volition,
and to delude or derange the senses.
Speaking generally and rather inaccurately, we might say
that the medicines of the first order of Narcotics bewilder and
impair the powers of the mind; those of the second order
subdue and extinguish them for awhile; and those of the
third kind excite and derange them.
Certain peculiar and exceptional effects are produced by
some Narcotics when they are administered in repeated doses
for a long time together. Taken in this way, Alcohol produces
delirium tremens, and great despondency of mind; as
also often a chronic inflammation of the liver. The continued
smoking of Tobacco is found to exert a tranquilizing influence
over the mind. And the continual use of Opium or
Indian Hemp, both of which are habitually consumed in large
quantities in the East, produces a curious and melancholy
series of mental hallucinations and disorders.
We have now to consider the third and last division of
Neurotic medicines. Sedatives are medicines which directly
depress nervous force. Some affect nervous force in general;
others confine their action to particular nerves. They are
mostly energetic and dangerous agents. For the time being
they may destroy nervous power, and remove nervous control.
It might already have been concluded, from what has been
said of the secondary action of Narcotics, that there are two
ways in which a Sedative action on nerve may be manifested.
Sedatives may destroy nervous influence; or they may simply
derange it.
Let us suppose a special Sedative to derange the action of
the Vagus nerve. It would probably cause the rhythmical
contraction of the heart to be abnormally slow or irregular.
It would be likely to diminish in the lungs the sensation of
want of breath, and thus decrease the number of the respirations;
and at the same time it would repress the irritability
of the pulmonary mucous surface. Further, it would in some
way derange the normal function of the stomach. All these
things a Sedative to the Vagus nerve does actually effect.
Given in large quantity, it may cause death, by destroying
those functions which in a small dose it deranges.
All the varieties in action of Sedative medicines may be
accounted for by considering that they may either derange or
destroy the nervous forces. In the case of each set of nerves
in the body we may distinguish an action of derangement,
and an action of destruction, both producible by Sedative
medicines. Thus by an action on the motor nerves of the
cerebro-spinal system, convulsions or paralysis may be produced.
By an influence on the nerves of sensation; pain, or
anæsthesia. By an affection of the organic nerves of the
heart, or of the brain which controls them; palpitation, or
syncope. By an action on the nerves of the lungs; cough,
or apnœa. By the exertion of a sedative power over those of
the stomach, nausea may result, or vomiting. These various
symptoms are all brought about by Sedative medicines, but in
each case the first effect is referrible to a derangement, the
second to a loss of nervous power. In every instance there
is an impairment of natural nervous force.
Narcotics act on the mind. They cause death, with stupor
or delirium. Sedatives act on the organic function of the
brain, which is necessary to life, but they do not affect the
mind. In poisonous doses, they kill by producing syncope,
which is a suspension of the action of the heart. Hydrocyanic
acid causes at the same time convulsions. These convulsions
appear to be caused by a derangement of the nervous
polarity of the spinal cord; and not by a stimulation of this
centre, as the tonic spasm of Strychnia. (Vide page 232.)
Sedatives are divided into two orders, according to the extent
of their action; in the same way as Stimulants have
been divided.
Sedantia.
Ord. 1. Sedantia Generalia.
Ord. 2. Sedantia Specifica.
General Sedatives have a direct action upon all the nerves
and nerve-centres in the body, the result of which is a diminution
of nervous force.
Special Sedatives exert the same depressing action upon
particular nerves only. Like the order of Special Stimulants,
they are peculiar and exceptional agents. All those with
which we are acquainted appear to direct their action to the
branches of the Vagus nerve.
It is among General Sedatives that the types or representatives
of this division are to be found. The definition of this
order does not admit of so great a variety in action as must
be allowed to Narcotics. A Stimulant medicine simply exalts
or increases nervous force; and a Sedative simply depresses
the same. But a Narcotic first does one thing and then the
other; and according to the degrees of these two actions, so
do some Narcotics resemble Stimulants, and others approach
very nearly to Sedatives. But we have seen that Narcotics
have also a peculiar and mysterious action on the mind, which
action is of three separate kinds. And the same three orders
which are named according to their respective actions on
the mind, are found to coincide with three stages of transition
from the action of a Stimulant to that of a Sedative medicine.
It is impossible to associate in the same prescription a Stimulant
and a Sedative medicine; for their actions are directly
contrary, and tend to counteract one another. But it is often
desirable to prescribe an Inebriant Narcotic with a Stimulant,
for their actions resemble each other so much, that they are
able to work together. And Deliriants, which stand at the
other end of the Narcotic scale, may often advantageously be
given with Sedatives, which they very much resemble in their
nervous operation. Thus, on the one head, Brandy may be
given with Ammonia; on the other hand, Hyoscyamus may
be prescribed with Digitalis or Hydrocyanic acid.
Ord. I. General Sedatives.
(Hydrocyanic acid. Creosote. Aconite. Conium. Colchicum.
Tea and Coffee.)
These are medicines which pass into the stomach, and are
capable of absorption; which are absorbed, and are proved to
act after passage into the blood. From the blood they pass
to the nerves and nerve-centres, and on all of them alike exert
a depressing influence. Some of them are much more powerful
than others. They do not exert any primary stimulant
effect, or any action on the intellectual part of the brain.
Most of them have special actions and tendencies.
Hydrocyanic acid is a powerful and dangerous medicine.
In large doses it very rapidly takes effect, producing convulsions,
syncope, and death. In small doses it is anodyne, and
antispasmodic. It is considered especially to influence the
reflex spinal system, and by this means may allay convulsive
cough, and quiet spasmodic movement. It is very useful in
Gastrodynia, and appears then to act locally upon the painful
and irritable nerves of the stomach.
Creosote stands, as a medicine, between Hydrocyanic acid
and Turpentine. It has a double action; being anodyne, like
the former; and a mucous stimulant, like the latter. Moreover,
it is a true Astringent, which cannot be said of Turpentine.
It is not powerful as a Sedative, but its peculiarity of
action often renders it useful in Gastrodynia. It is particularly
applicable when pain in the stomach is accompanied with
a tendency to hæmorrhage, or with a probable relaxation of
the mucous coat.
Aconite is a powerful anæsthetic to the superficial sensory
nerves. When applied in solution or ointment to the surface
of the skin, it produces first some heat and tingling, which is
attributable to a derangement of the nervous influence; and
this is succeeded by perfect numbness. It is thus a most
valuable topical remedy in true irritative Neuralgia. Other
Sedatives and Narcotics have the same power as topical anodynes,
but not in so marked a degree. In large doses Aconite
is a General Sedative; producing tingling of the extremities,
vomiting, and syncope; and affecting the brain in various
ways, as will be shown by some experiments which I have
made upon its action, to be detailed in the fourth chapter.
An alkaloid called Aconitina, the most powerful of all known
medicines, is the active principle of this drug.
Conium (Hemlock) also owes its properties to the alkaloid
Conia. Dr. Christison has made some experiments upon the
latter. He found that it produced swiftly-spreading paralysis
of the motor nerves; and he considers it to act particularly
as a Sedative to the reflex spinal functions. It also paralyzes
the sensory nerves, but in a less degree.
Conium is certainly anodyne; and produces often a sedative
action on the heart. It would thus appear to be a General
Sedative. But in some recorded cases of poisoning by Hemlock,
coma has been mentioned as a leading symptom. Were
this to be authenticated, and shown to be the invariable result
of the action of this medicine in large doses, then it ought
certainly to be classed among Narcotics. Dr. Pereira considers
it likely that the plant contains more than one active
principle. Hemlock has a paralyzing action on the nerves
of motion, which is directly the reverse of the stimulating action
of Strychnia; and is thus of use in cases of convulsion
and spasm. It is also often prescribed as an anodyne.
Conium is further said to have a curious resolvent power
over glandular enlargements, and to have thus frequently
caused their absorption and disappearance. This action was
first noticed and described by Dr. Fothergill. All true resolvents
operate by an action in the blood, but it is difficult
to conceive how such an action can be exerted by a nerve-medicine.
It may possibly act indirectly by quieting the
action of the heart, and controlling an irritable state of the
nervous system. In the same way Opium often appears to
act as a resolvent. And it is certain that Hemlock, when
used for this purpose, very often fails altogether. It has been
wrongfully extolled as a panacea in Phthisis; but is in fact of
no greater use in that disorder than Hyoscyamus, Prussic
acid, and other medicines which reduce the pulse. For the
patient in this disease is devoured by a continual slow fever,
and any thing which tends to lower this fever will serve to prolong
his existence. But altogether it must be admitted that
considerable mystery attaches to the operation of this medicine.
Colchicum has many different actions. It has an agency
in the blood, being Antiarthritic. It is an Eliminative, acting
on the liver and bowels. And it is also a General Sedative.
To the combination of an eliminative with a sedative
or anodyne action, the use of Colchicum in Gout has been, I
think, erroneously ascribed. For in fact it seems to act best
in this disorder when it causes no purging, and scarcely any
action on the nerves. When it has been long used, it causes
a great depression of the spirits, like that which may be
caused by some undoubted blood-medicines, as Mercury. But
it does not affect the understanding, or the special senses. In
poisonous doses it depresses the circulation and the nerves generally,
but it causes no stupor or insensibility. It is therefore
not a Narcotic; but, like other Sedatives, it kills by syncope.
In the behaviour of the system towards Colchicum, Aconite,
Digitalis, and other nerve-medicines, there are two peculiarities
which are worthy of remark. They are called cumulation
and toleration.
Some quantity of the medicine may often be given, in repeated
doses for some time together, without any apparent
result. It seems to remain in the blood, and to become
accumulated or stored up there. But all on a sudden it
breaks out, appearing to be discharged on the nerves, and
may produce very dangerous symptoms. This cumulative
action is especially observed of Digitalis, and therefore considerable
care is required in the exhibition of that medicine.
This medicine is a Special Sedative, and will be presently considered
as such. In other cases we find that the nervous
system becomes by degrees inured to the effect of a particular
medicine, and suffers less by its presence than it did at first.
This is called toleration. It is particularly observed of Colchicum
and of Antimony, and of all medicines which act on
the Vagus nerve so as to cause vomiting.
Tea and Coffee, common articles of diet, are slightly sedative
to the nervous system generally. They lower the pulse,
and, by diminishing congestion of the brain, tend to clear and
tranquilize the action of the mind. This activity of thought
is endangered by the cerebral congestion which exists early in
the morning, on account of recent sleep,—and again towards
the evening, from the full meal of the middle of the day. It
is thus at these times that they are found so useful, and are
so universally adopted. They are, in fact, almost indispensable
to the daily existence of civilized man, with whom a continual
energy of mind is a necessary of life. Infusions of these substances,
or of materials similar to them in medicinal nature,
are adopted as a daily beverage by all civilized nations. By
diminishing congestion of the brain, Tea and Coffee have not
only the effect of clearing the mind, but in large quantities
they induce wakefulness. This is particularly the case with
Coffee. It is not clear that Tea, as commonly drunk, is ever
unwholesome. Green Tea is a more powerful sedative, and
resembles Coffee. Coffee has a more potent influence over
the mind and nervous system than is possessed by Tea, and
is apt to disagree with many persons. Like Opium, but in
a far less degree, Coffee tends to confine the bowels. By
diminishing the congestion of the brain which is produced by
Opium, strong Coffee is of use in cases of poisoning by the
latter substance.
Tea and Coffee are sometimes said to be mental exhilarants;
but they only become so indirectly, by removing congestion,
which is a cause of stupidity.
Both Tea and Coffee contain the alkaloid Theine; but it is
probable that their Neurotic action is not so much owing to
this, as to a volatile oil, which exists in both in some quantity.
Ord. II. Special Sedatives.
(Antimonials. Ipecacuanha. Digitalis.)
These are medicines which, like the last, depress nervous
force, yet they do not exert their influence on the nervous
system as a whole, but only on certain parts of it. So far
they resemble Special Stimulants; but their effect is of a
directly opposite nature. They have also no direct influence
on any part of the brain.
Antimony, Ipecacuanha, and Digitalis, have each of them
a number of different actions. The first has already been included
among Catalytic Hæmatics, as tending to counteract
in the blood the process of inflammation. But it possesses
further a Neurotic power, by which it is gifted indirectly with
a more powerful control over acute inflammations than could
be exerted by any slow-acting blood-medicine. It is also
Eliminative. Passing out of the body through the glands of
the skin, it becomes a Diaphoretic. This may be its only
action when it is given in doses too small to act upon the
nerves. It must not be confounded with the diaphoresis
which accompanies the condition of nausea, and which is
probably produced in another way. Ipecacuanha is in the
first place a Neurotic, of less power than Antimony; in the
second place an Eliminative, increasing expectoration, as well
as Diaphoresis. Digitalis too acts first upon the nervous
system; then on the kidneys, being a Diuretic.
But we are now concerned with the special Neurotic actions
of this group of medicines. They all exert an influence over
the three functions of respiration, circulation, and digestion.
They affect the heart, lungs, and stomach, parts which are
supplied by the branches of the Vagus nerve, as well as by
the Sympathetic. Their action is not an external action, for
it is produced when they are introduced into the blood at any
part. Thus Tartar Emetic or Ipecacuanha, when injected in
solution into one of the veins, will cause vomiting. M.
Magendie has found that in the case of dogs they also produce
Pneumonia. The mere inhalation of the dust of Ipecacuanha
has been found to act upon the lungs so as to cause
Bronchitis. These actions, as well as the various effects which
are found to follow the introduction of these medicines into
the stomach, can only be explained satisfactorily by supposing
that they act as Sedatives to the branches of the Vagus nerve,
thereby deranging or destroying the natural influence of that
nerve in the direction and regulation of the organs which it
supplies. For we have already seen that the action of a
Sedative medicine is of such a nature as to derange nervous
force in some cases, and simply subdue it in others.
These actions are obviously nervous actions; for they are
quick, sudden, and transient, and confined to parts supplied
by a particular nerve. They are exerted upon nervous forces,
and not upon the blood. If then they are nervous operations,
they must either be directed towards the Vagus, or to the
Sympathetic nerve, for these are the only nerves which supply
the parts influenced by these medicines. They cannot act
upon the Sympathetic, for two reasons. If they did so, we
might reasonably expect that the other parts of this nerve
would be influenced at the same time. But this does not
appear to be the case. And again, an action upon the Sympathetic
nerve could not be suddenly and violently evidenced,
for the natural action of this nerve is slow, chronic, and persistent.
At all events, the effects for which they are used
could not be produced by an affection of this nerve.
We may therefore conclude that the action of these medicines
is exerted upon the Vagus nerve and its branches.
They affect the different parts of the Vagus nerve in variable
proportion.
Some apparent anomalies in their physiological influence
may be explained by considering the peculiarities which attach
to all sedative actions. Thus we have seen that when given
in large doses to healthy persons, Hydrocyanic acid produces
convulsions by deranging the reflex spinal functions; and
that in convulsive affections, when the same functions are
disordered, the same remedy may do good by subduing their
excited condition. On similar grounds, Tartar Emetic, injected
into the veins, may produce Pneumonia; and Ipecacuanha,
introduced as dust into the lungs, causes Bronchitis or
Asthma; and yet Tartar Emetic is advantageously employed
in the cure of Pneumonia, and Ipecacuanha is a remedy for
Bronchitis. When the function of the healthy nerve, or that
part supplied to the lungs, is deranged to a certain degree,
an inflammation of the mucous membrane or substance of
the lung is a natural result. But when these tissues are
already inflamed, a course of medicine, which at the same
time subdues the action of the heart, and represses the irritability
of the nerve supplied to the part will be likely to effect
a cure. They are both sedative actions; but the first is an
action of derangement, the second one of depression. This
seems to me to be the correct explanation of a difficult matter.
It was just now observed that these medicines affect the
functions of the Vagus in different proportions.
The action of Ipecacuanha, when given in repeated small
doses, is particularly directed to the pulmonary organs. It
allays the sensation of want of breath, and diminishes the
cough, of Bronchitis. In larger doses it produces first nausea,
then vomiting.
Still more decided nausea is produced by Tartar Emetic.
It is followed by vomiting when the dose is sufficiently large.
Nausea consists in a sensation of discomfort about the præcordial
region, which is due to a derangement of the stomach,
with a feeling of great languor, a cold perspiration and tremor,
and at the same time a striking depression of the action of the
heart. This nausea may be caused without vomiting, by a
regulation of the dose. On account of the depression of the
heart's action, which is its chief symptom, it is often very
desirable to cause nausea in acute inflammations and fevers.
It is kept up by the careful administration of Tartar Emetic.
It may not be so desirable to produce vomiting; for this is
accompanied with great vascular excitement and active congestion
of the brain. And yet it is found that the more
Antimony we can get into the blood, the more potent and
durable will its antiphlogistic influence be. For this medicine
appears to possess a blood-action as well as an action on nerve.
Experience has shown that if the dose of Tartar Emetic be
gradually increased on each repetition, it may often be
tolerated by the system; that is, it does not produce vomiting;
and then the remedy, being absorbed, is better able to
continue its antiphlogistic and nauseating action. For the
act of vomiting, besides other bad consequences, causes the
rejection of that part of the antimonial which has not been
absorbed. By the operation of the Nauseant the violent
action of the heart in high fever may be allayed. It is often
of signal efficacy, most especially in Pneumonia.
Digitalis given in large doses may also act on the stomach,
and cause vomiting. This operation has been ascribed, erroneously,
as I think, to an irritating action possessed by this
drug. But in smaller doses it affects the heart and circulation
powerfully, without producing the other symptoms of
nausea. It depresses the action of the heart. Sometimes
the rapidity of the beat is slightly increased at the first, but
the pulse at the same time is weaker. It soon becomes
slower and sometimes irregular. This action is characteristic
of derangement of the Vagus nerve. For it was found,
in some experiments on animals made by M. Weber, that
when the function of this nerve was disturbed by mechanical
irritation, the rate of the heart was first accelerated, its action
then became slow and irregular,—and finally it stopped. There
cannot be a greater mistake than an attempt to explain such
a derangement by supposing this medicine to exert a primary
stimulant action. Coincident with the quickening of the
pulse, there is a manifest loss of power.
Digitalis is especially useful in dropsies which result from
an obstruction to the cardiac circulation. By subduing the
action of the heart, it relieves that congestion of the vascular
system which is the cause of the effusion of serum. But it
is also a Diuretic; and may thus too relieve the loaded vessels
by carrying off in the urine some of the water of the blood.
Such is an outline of the action of Special Sedatives to the
Vagus nerve. It is not clear whether they affect that nerve
at its origin in the brain, or whether they act the extremities
of its filaments.
These Sedatives do not act directly upon the brain itself.
But indirectly they may affect it, when given in large doses.
For by depressing the action of the heart they cut off the
natural supply of blood to the brain, and may, by so doing,
produce delirium and convulsions. They tend obviously to
kill by syncope. Some medicines may cause syncope by an
action upon the brain. General Sedatives may do so; but it
does not appear that the medicines of this order ever act in
this way.
Some other medicines rest very closely upon the confines of
this order. Squill is the chief of these. It is not quite clear
whether Squill should be regarded as a Special Sedative, or
considered simply as an irritant Emetic and Eliminative. It
is a valuable Expectorant. It is also a Diuretic; and from
the analogy of its operation to that of Digitalis (vide supra,)
and because it appears to be a specific Emetic, it is most probably
a true Neurotic.
But we must not confound with Neurotics those medicines
which exert a slow operation in the blood which results at
length in a nervous affection. This may take place, to a
greater or less degree, with all Catalytic Hæmatics. Lead,
which is anti-convulsive and astringent, approaches nearest
of all to the recognised nerve-medicines. After existing for
some time in the blood, it produces local palsy, particularly
of the muscles about the wrist; and it sometimes affects the
sensory nerves, causing sharp shooting pains in the limbs.
These nervous symptoms are caused by the accumulation in
the system of the poison of lead, and the deterioration of the
blood which is thereby produced. In the case of the palsy,
we cannot certainly say whether these causes operate first
upon the motor nerves, or upon the muscles themselves.
Lead certainly has some tendency to affect the brain. All
kinds of brain disorders may occur in cases of chronic lead-poisoning.
The metal has been found in the brain after
death; but it also exists at the same time in other parts of
the body. In cases of Lead-colic there is generally a paralysis
of the muscular fibre of a certain portion of the intestine.
The pain of the disorder is caused by an irritation of the
nerves of the part.
Neurotics are medicines which tend, immediately they enter
the blood, to be discharged from it upon the nervous system.
They therefore immediately affect the latter. Hæmatics, in
small doses, pass through the blood without exerting any
direct effect upon the nerves. They are never discharged
upon the nervous system except after they have for some time
existed in the blood in such quantity as materially to vitiate
its healthy character. Corrosive poisons affect the nerves by
a violent revulsive action; and are not to be considered in the
same category as medicines. Thus Lead is not a true Neurotic,
but a blood-medicine. (Vide page 175.)
We have now concluded our brief review of the action of
Neurotic medicines. Some few will be again treated of in
the fourth chapter. The views of their operation which I
have wished to substantiate are in many cases the same as
those which are generally adopted, in some cases different from
them. In either instance I have attempted to base them on
observation, or on simple inductive reasoning.
It has already been observed that these nerve-medicines are
more rapid and more evanescent in their action than those
which preceded them. They are unable, as a general rule, to
produce a permanent effect. When such a permanent impression
is desired, an approach to it can be made by a continual
repetition of the dose, by which a transitory action
may be constantly renewed and kept up. In other cases a
mere transitory action may produce a cure. This may be the
case in a sudden and dangerous emergency, which will pass
over if the system can be supported through it, but which
threatens life while it lasts. Or in Neuralgia, if the irritability
of the sensory nerve be continually blunted by the
external application of Aconite, it may at last subside altogether,
and a right condition of things be restored. The
same may be said of convulsive disorders, and the stimulant
antispasmodics which are used to control them.
Neurotics are mostly employed in temporary emergencies.
In such cases their action is often decisive and gratifying.
Vital action may be restored and kept up; or excess of action
allayed. Pain may be suddenly and effectually removed;
delirium or convulsions subdued. Sleep may be substituted
for wakefulness, or activity for torpor. By these powerful
remedies we are enabled to exert an immense control over
the varied manifestations of nervous force; and may often,
when we wish it, substitute one condition for another which
is the reverse of it. When there is a deficiency of nervous
force, we make use of a Stimulant, or of one of the Inebriant
Narcotics; when there is an excess of the same, we employ a
Sedative, or one of the latter two Narcotic orders.
But when we desire to quell a long-standing and firmly-rooted
disorder, which is not displayed by violent outward
manifestations, but is nevertheless working fatally within, we
must then call to our aid some Hæmatic medicine, which
alone can be of permanent efficacy in such a case.
Although this class of Astringents is a small and comparatively
unimportant class, yet it is necessary to separate it
from all the others, because the medicines which compose it
are completely distinct in their mode of operation. They do
not necessarily act in the blood, although many Hæmatics
are also astringent. They do not pass from the blood to the
nerves. They do not always act by passing out of the body
through the glands. Their operation is peculiar, but it is
simple. As Neurotics act directly on nerve, so these act
directly and especially on muscular fibre. They cause this
to contract, whether it be striped and voluntary, or of the
involuntary unstriped kind.
Their action is more readily understood, because it can
actually be seen. It takes place out of the body, or in the
body—externally, or internally. Nearly all astringents have
the power of coagulating or precipitating albumen. By virtue
of this power they are enabled to constrict many dead animal
matters. They affect fibrinous tissues in a similar chemical
way. But they seem to possess a further dynamical influence
over living tissues, which possibly depends in some way
on this chemical property. This dynamical influence is, as
I have said, to cause the contraction of muscular fibre. By
this all their operations can be explained. Taken into the
blood in a state of solution, they pass through the walls of
the capillaries to the muscular tissue. By inducing the fibre
of the voluntary muscles to contract, Astringents may brace
the system, and simulate the action of Tonics. But as the
contraction of voluntary muscle is short and brief, it requires
for its maintenance a continual excitation, and unless the
medicine is thus continually repeated, the tonic effect subsides.
But astringents further contract involuntary muscle.
This contraction is slower, and more durable and important
in its results. Unstriped muscular fibres exist in the middle
coat of arteries, in the walls of capillary vessels, in the lining
of the ducts of glands generally, and in the substance of the
heart and the coats of the stomach and intestines. Astringents
are irritant and poisonous in large doses. But in small
doses they constrict and stimulate to a healthy condition these
tubes that contain in their coats the unstriped fibre. By
diminishing the caliber of the capillary vessels generally, they
promote health, and counteract a lax state of the system. By
the same action on the extreme vessels, they prevent hæmorrhages.
By constricting the ducts of the glands they diminish
the secretion of those glands, because denying it an exit.
By acting on the stomach and intestines, they are able to
give them tone, to diminish their secretions when excessive,
and thus to promote digestion.
Having premised this general view of their action, we may
now proceed to prove the Proposition in which it is stated,
dividing it first into four minor propositions.
m. p. 1.—That they are medicines which pass into the blood.
m. p. 2.—That they have the power of causing the contraction
of muscular fibre, living or dead.
m. p. 3.—That their operation is to diminish secretion, to
repress hæmorrhage, and to give tone to the
muscular system.
m. p. 4.—That these results are to be accounted for by their
action on muscular fibre, to which they pass from
the blood.
These assertions are an extension of the major proposition,
but their establishment is necessary to a correct understanding
of the latter. Their proof is comparatively easy and
simple. It is not supposed to be a certainty; but simply to
amount to a strong probability, which is as much as we have
a right to expect in such cases.
Astringents constitute the third class of medicines which
operate on the system after being introduced into the stomach.
Their action is, however, of so simple a kind, that it may be
exerted on the external surface in the same way as in the
interior of the body. It will be seen by a reference to the
table of medicines, that the class of Astringents is there
divided into two orders.
Astringentia.
Ord. 1. Astringentia Mineralia.
Ord. 2. Astringentia Vegetabilia.
The lists of these orders are given below. With regard to
the first minor proposition, it has already been proved that
most of these medicines pass into the blood. The minerals
included in the first order have already been noticed as
Hæmatic medicines. They are all soluble in water. They
are absorbed in the stomach and intestines, and pass into the
blood. Many of them pass on into the secretions. The astringent
parts of the vegetables of the second order are also
soluble. Tannic acid is the chief of them; it is simply an
Astringent; it has been found in the blood, where it changes
into Gallic acid, and in that form it passes into the secretion
of urine.
What then are the active properties of these medicines?
They have all a certain chemical power; and a certain dynamical
power. All the mineral Astringents have the power
of precipitating an albuminous solution. So also do Tannic
acid, Turpentine, and Creosote, coagulate albumen. Tannic
acid precipitates Gelatine too. The dynamical property,
which is common to all of these substances, is a power of
causing the contraction of muscular fibre. It seems to depend
somehow on the chemical power just mentioned; for
Astringents appear to constringe fibrinous as well as albuminous
tissues by a chemical action. They also coagulate fluids
and discharges which contain albumen.
When the solution of any Astringent is applied to a fresh
fibre of dead muscle placed under the microscope, it is seen
to contract. The power which they possess in causing the
contraction of living blood-vessels may be witnessed in a
similar way. The astringent solution may be applied to the
web of a frog's foot, confined in an extended position. This
web is traversed in all directions by minute ramifying capillaries;
and these are found gradually to diminish in caliber.
In the same way as the mechanical irritation of a small artery
will act upon the unstriped muscular fibre contained in its
coat, and thus cause the vessel to contract at one point; so it
seems that an Astringent, by a chemical action on the same
muscular tissue, is able to cause the capillary vessels seen
under the microscope to contract and diminish in size. At
all events we may conclude, both from actual experiment and
from a comparison of their several operations, that Astringents
are able to cause the contraction of muscular fibre.
In the third minor proposition the chief results of their
operation are stated. These have already been briefly described.
They check secretion. They are thus prescribed when any
secretion is excessive. The Tannic vegetables are given in
diarrhœa; Nitrate of Bismuth is administered in Pyrosis;
Sulphuric acid in profuse perspirations; Uvæ Ursi in mucous
flux from the bladder.
They repress hæmorrhage. Thus Acetate of lead is employed
in hæmoptysis; Creosote and Uvæ Ursi are used in
hæmorrhage from the stomach or bladder; and the vegetable
Astringents are prescribed in Dysentery.
They give tone to the system. They do this when there
exists an over-relaxation of the solid fibres on account of any
depressing cause, by exciting the muscles to a more or less
permanent contraction, and by constringing the capillary
vessels generally.
In the fourth place, it is maintained that their action in
all these instances may be explained by a reference to their
power in causing the contraction of muscular fibre; inasmuch
as they are found to diminish the caliber of certain tubes and
cavities, and these owe the contractility which they possess
to the muscular fibre which is contained in their coats. It
follows then from the rule of local access, that before they
can influence these tissues they must pass directly to them
from the blood.
Such appears to be the simplest and the most rational explanation
of the action of Astringent medicines.
Ord. I. Mineral Astringents.
(Sulphuric, Nitric, and Hydrochloric acids. Acetate and
Diacetate of Lead; Sulphate and Sesquichloride of Iron;
Alum; Sulphate of Zinc; Sulphate of Copper; Bichloride
of Mercury; Nitrate of Silver.)
These medicines have already been noticed among Restorative
and Catalytic Hæmatics. Their Astringent action on
muscle is of much less moment than their important operations
in the blood. Neither is it theoretically a matter of so
much difficulty; for it appears, as we have seen, to admit of
a simple explanation.
By their chemical action on albumen, these substances
coagulate blood, and thus act in a simple way as styptics
when applied to bleeding parts externally. They form peculiar
insoluble compounds both with albumen and fibrine, and
it is probably by virtue of their action on the latter that they
are able to cause the contraction of muscular fibre, which is a
fibrinous tissue. The constriction, set up chemically, is apparently
continued and propagated by the vital force of the
muscle.
The most important only of the mineral Astringents are
mentioned above. It must not be supposed, when their chemical
actions are mentioned, that such actions are always
allowed free play in the living and circulating blood. They
are no doubt constrained by various forces from operating
there, or else the consequences of such a disturbance of the
condition of the elements of the blood would be dangerous
in the extreme. (Vide page 104.) They act, before entry
into the blood, on mucous membranes and external parts;
and on coming out of the blood, on the terminal capillary
vessels, on the ducts of glands, and on mucous membranes
again.
Astringents act very much alike on external parts; only
that some are more soluble than others, and some excel the
rest in chemical activity. But they differ considerably in
their applicability for internal use. They must be given in
such quantity that, after absorption and dilution by the whole
mass of the blood, they may still be capable of exerting a
perceptible action on distant parts. A small portion of one
of them will not suffice to repress hæmorrhage, or to diminish
a super-abundant secretion.
From this it follows that the mineral acids, Alum, and the
salts of Iron, are the only astringents of this order which can
in all cases be given internally with advantage. For being
comparatively innocuous, they can be safely prescribed in the
quantity required; whereas the other mineral Astringents are
poisonous substances, which cannot be given in large doses
without considerable danger.
Of the mineral acids, Sulphuric acid is the best Astringent.
Phosphoric acid is seldom or never used as an Astringent.
We might indeed have supposed it to be inapplicable, from
the fact that it forms soluble compounds with albumen and
fibrine,—instead of coagulating these substances, like the
other mineral acids.
Sulphuric acid is a Restorative Hæmatic; and, when given
in small doses, may remain in the blood, and not pass out
through the glands. It acts first upon the mucous surface
of the stomach. When there is a relaxation of this mucous
membrane, as in many cases of atonic dyspepsia, with a large
formation of flatus, and an over-secretion of the gastric fluid,
this acid may be very serviceable. It tends to correct these
evils by a topical action. In cases of Pyrosis, where there is
an alkaline reaction in the vomited fluid, as sometimes occurs,
Sulphuric acid is still more peculiarly applicable, because it
further acts chemically in neutralizing this alkali. When
given in large doses, the acid cannot remain in the system,
but must be excreted from it by the glands. In passing
through them it tends to act as an Astringent by corrugating
and diminishing in caliber their minute ducts, and thus decreases
the amount of the secretion. But it does not act on
all glands alike. Dr. Bence Jones has found that it seldom
passes out into the urine. It therefore does not sensibly
diminish the secretion of urine. It is probably excreted
partly by the skin, and partly by the bowels; for it diminishes
the amount of the sweat in profuse perspiration, and
of the fæces in diarrhœa. Sulphuric acid is free before
entrance into the blood, and after expulsion from it into the
secretions. Thus at these periods it acts as an Astringent.
But while in the blood it combines with the alkali contained
in that fluid, and forms a salt which is not astringent. So
that when it diminishes any secretion, this is nearly tantamount
to a proof that it is actually excreted by the gland
which forms that secretion. It acts on mucous membranes
generally, being probably excreted in small quantities by
those which are remote from the stomach. It is not of use
in cases of hæmorrhage, except when the bleeding takes place
from some mucous membrane. It is thus given with more
or less advantage in Hæmatemesis, Hæmoptysis, Melæna,
and chronic Dysentery—i.e. in hæmorrhage from the mucous
surfaces of the lungs, stomach, and bowels.
Alum is a universal Astringent, acting more or less on all
parts of the body, and diminishing all secretions. It is a very
useful remedy in all cases where Astringents are required. It
does not seem to be impaired in power while in the blood, as
is the case with Sulphuric acid; and is therefore applicable in
all hæmorrhagic cases. It has been highly recommended in
the case of lead colic, and seems to operate in this instance
by stimulating to contraction the muscular fibre of a paralyzed
portion of the intestine.
The astringent salts of Iron are less active in this kind of
influence than the medicines already referred to. They have
very little action on the glands. But in cases of hæmorrhage
they are particularly appropriate, for in addition to their
astringent action they tend to restore the deficient red colouring
matter of the blood. In many such instances the Sulphate
or the Sesquichloride of Iron may be advantageously prescribed
along with Sulphuric acid.
Acetate of Lead is used internally as an Astringent, but
being a more dangerous remedy than the medicines above
mentioned, it requires greater care in its application. It
should not, if possible, be used long at a time. When it
has been for some time prescribed, the blue line at the edge
of the gums, which is characteristic of a saturation of the
system by the poison of lead, will indicate that its further
administration is unadvisable. The Acetate of Lead is much
esteemed as an Astringent in the case of Hæmoptysis. It is
frequently combined with Opium, in spite of the chemical
decomposition which follows the admixture. But it must
certainly not be prescribed with Alum.
The soluble salts of Silver, Zinc, and Copper, and the Bichloride
of Mercury, are used with advantage as external
Astringents, but can seldom be prescribed internally so as to
act in this way, because they are poisonous when given in any
quantity. The Sulphates of Zinc and Copper have, however,
been occasionally used in diarrhœa.
When thus applied as Astringents externally, their solutions
must be very dilute, for all the mineral Astringents are caustic
and corrosive, destroying texture, when in the solid state, or
in strong solutions. These solutions may be applied to any
part of the surface of the skin or mucous membrane, when
relaxed, inflamed, or ulcerated. Their operation is simple and
obvious. When one of them is applied to an inflamed eye, or
to a red ulcerated sore, that is turgid with blood and discharges
an unhealthy matter, it tends to promote the contraction
of the dilated vessels, and thus dispels the congestion and
diminishes the discharge.
Various other substances have wrongly obtained the title of
Astringents, regard being had only to the result of their operation,
and not to the mode in which it is produced. Thus
Chalk is often of benefit in diarrhœa. It acts both by mechanically
absorbing irritating fluids, and protecting the surface
of the bowel, and by chemically neutralizing an acid
matter by which the irritation is maintained. And when
applied to the surface of inflamed ulcerated parts, it does good
by absorbing the discharge, and protecting from the contact
of air. Thus its action in both cases is very different from
that of the true Astringents.
The action of some of the minerals above named, when applied
externally in the solid state, as caustics, must not be confounded
with their astringent power. Its efficacy depends upon
the revulsive effect which follows a local destruction of tissue.
Ord. II. Vegetable Astringents.
(Tannic Acid. Gallic Acid. Kino; Catechu; Logwood;
Oak-galls; Rhatany; Bistort; Pomegranate-rind; Rose-leaves;
Uvæ Ursi; Tormentil. Creosote.)
Tannic Acid, Gallic Acid, and Creosote are the three chief
Vegetable Astringents. To the first two the vegetable substances
above enumerated appear to owe their efficacy. All
contain Tannic Acid, or some modification of it; and Oak-galls
contain also Gallic Acid.
The relative efficacy of these active principles may be
summed up in a few words. Tannic and Gallic Acids may
generally be used with great advantage in all cases in which
Astringents are required. When applied externally, Tannic
Acid is the most powerful; but for internal administration
Gallic Acid is the best. The reason of this will presently appear.
Creosote, being a powerful Neurotic, cannot be employed
to act on distant parts, but is appropriate in cases of
hæmorrhage from the surface of the stomach.
I have already said that I conceive the astringent powers
of these substances to depend very much upon their chemical
affinities. Tannic Acid precipitates both Albumen and Gelatine.
Creosote also coagulates Albumen. But Gallic Acid
does not affect either of them.
Tannic Acid does not seem to be a simple substance. When
boiled with acids, or with alkalies, it yields Gallic Acid and a
brown matter. Tannic and Gallic Acids yield the same set of
products when submitted to destructive distillation. And it
appears likely, from the researches of M. Braconnot, that
Tannic is a compound acid consisting of Gallic Acid in combination
with the elements of grape-sugar. Three atoms of
Tannic Acid are together equivalent to six atoms of Gallic
Acid and one of grape-sugar. When the solution of the
former acid is heated in the air, or taken into the human system,
the elements of grape-sugar are oxidized into Carbonic
Acid and water, and Gallic Acid is set free. (Vide Chap. IV.
Art. Tannic Acid.)
It is thus Gallic Acid which passes out into the secretions,
and exerts an astringent action at distant parts of the system.
And as the Tannic Acid loses weight by the decomposition, it
follows that a dose of Gallic Acid produces a greater effect as
a medicine than an equal amount of the other. Thus one
ascertained fact is cleared up by these chemical considerations,
but other mysterious points remain still to be explained.
Gallic Acid does not precipitate albumen, and is of little
use as an Astringent when applied to external parts; but it
is very efficacious when given internally. Tannic Acid, which
is equivalent in composition to a combination of Gallic Acid
with a saccharine matter, is a valuable external Astringent.
A further chemical discovery has been made, which appears to
bear upon these facts. M. Pelletier has found that a mixture
of a solution of Gallic Acid with one of Gum will precipitate
albumen, although neither of them will affect it separately.[43]
Gum has the same composition as common sugar; and
grape-sugar, or a material containing the same elements, is
known to be continually forming in the blood. Thus it is
likely that Gallic Acid may act along with this saccharine
matter in the blood, and by this acquire chemically an astringent
power, which it is not able to exert on external parts,
because then isolated. But the saccharine matter is required
in the system for special purposes, and thus Gallic Acid passes
out into the secretions alone.
It seems probable, when Tannic Acid is given, that it is not
decomposed into its constituent parts until it has to be separated
from the blood by the glands.
These two compounds, and the vegetable substances that
contain them, are used in diarrhœa, and in all hæmorrhagic
cases. To diminish sweating, Tannic is inferior to Sulphuric
Acid; but to act as a remote Styptic, it is preferable to the
other. Tannic and Gallic Acids diminish secretions generally;
they are very useful in cases of hæmaturia, where Sulphuric
Acid is all but useless.
Creosote is a Sedative, and cannot be well given in such
large doses as to act upon distant parts. In cases of hæmatemesis
it acts topically on the surface of the stomach in a
double way, diminishing the hæmorrhage by its astringent
power over the vessels, and quieting the nervous irritation by
which the vascular excitement is often maintained. In cancerous
cases the bleeding can never be permanently stopped.
This concludes the list of Astringent medicines.
Certain stimulant Eliminatives are employed for the purpose
of checking mucous fluxes, and so far simulate the action
of true Astringent medicines. Thus we administer, with more
or less advantage, Aromatics in diarrhœa; Cubebs, Copaiba,
and Turpentine, in gonorrhœa; and Balsam of Peru, and other
oleo-resins, in Catarrhal affections. These medicines all act
upon and pass through the glands of the several mucous surfaces
which they affect: while so doing, they stimulate the
healthy function and secretion of the gland, and cause it to
displace the morbid one. Dr. Williams thinks that they first
cause dilatation of the vessels of a gland, and that this is followed
by contraction. There is no apparent reason why the
latter effect should succeed the former. But supposing contraction
to take place in this way, then these medicines would
be true Astringents. But it cannot be so, for they do not
diminish any of the natural secretions, but, on the contrary,
increase them. Turpentine, Cubebs, and Copaiba, are Diuretics,
and it is possible that while passing out in the urine
they may simply stimulate the mucous surface of the inflamed
urethra, and excite it to a healthy action.
These volatile oils are incapable of exerting a true astringent
action. On the supposition that it is really an Astringent,
Turpentine has been often prescribed as a remedy for
hæmorrhages in different parts of the body. But it has very
much disappointed the expectations that were entertained of
its efficacy.
General Stimulants may act indirectly as styptics to a mucous
surface, when relaxed and bleeding on account of an
atonic condition of the nerves by which the contraction of
the minute vessels is maintained.
Alcohol, in large quantity, coagulates albumen, and it may
thus act as a true Astringent when applied externally.
Some Neurotic medicines diminish secretions in a way
which is not well understood. The chief of these is Opium,
which particularly diminishes the secretion of the bowels.
Attempts have been made to explain this by an influence possessed
by Morphia on the process of Endosmosis, but they are
not satisfactory. Some little light may perhaps be thrown
upon the matter by a consideration of the other operations of
Opium; but it is difficult to explain it decisively in any way.
In this Fourth Class are included all the medicines which
tend in a direct manner to increase secretion. They have
received various appellations: some authors have called them
special Stimulants; others, as Dr. Duncan, have named them
Evacuants; while Dr. Pereira entitles them Eccritics.
The mode of operation of Eliminative medicines is a matter
of considerable importance, and its consideration will require
us first to make some inquiry into the character and
functions of those important glandular organs which they are
said to excite to action.
The rational explanation of the process of elimination or
secretion has been in all ages of science a favourite topic for
speculators and theorists,—sound or unsound in their views,
according to the light that was given to them. With regard
to its essential nature, and its immediate bearing on the cure
of disease, the subject has been generally understood with
tolerable clearness. From the time of Hippocrates downwards,
the use of Evacuants in the treatment of fevers and
other disorders has been recognised, and their efficacy usually
explained by supposing that they caused the passage out of
the body through the glands of certain matters that were
formed in the blood, but ought not to remain in it.
This view was more particularly insisted on towards the
close of the seventeenth century by Dr. Thomas Sydenham;
and again at the commencement of the eighteenth by Dr. A.
Pitcairn, in an Essay on the use of Evacuants in Fevers.
These both had observed that fevers and other disorders had
mostly a particular tendency to pass off with an increase in
one or more of the secretions; and they drew from this, and
from the results of their experience, that in stimulating and
urging this secretion, the physician would be doing his best to
promote a cure. (Vide page 55.) More recently the same
idea has been followed up by Cullen, Hamilton, and others.
This theory is not in our immediate province. Though
based upon reasonable grounds, it has perhaps been too universally
applied. It will suffice now if we assume that remedies
whose action is to increase the amount of secretion have
often an important bearing on the cure of disease. We have
only to inquire into their manner of action. As a preliminary
step, there is one general law of secretion which it is of importance
that we should clearly lay down. It is this: it is
the special office of each gland, or set of glands, to secrete
from the blood particular materials, and to pass them out of
the body.[44]
It follows from this law of selective secretion, that when
any morbid substance or product,—or any thing which is in
the system, but cannot naturally remain there,—has to pass
out, it prefers to pass by some glands rather than by others.
It must be remembered that the glands afford the only means
by which a substance can make its exit from the blood. We
are still much in the dark as to the rationale of this force or
attraction, by which particular matters are drawn towards
each gland.
Dr. Pitcairn, a great man for the age in which he lived,—a
man of original thought and natural genius,—gives us, in his
Essay on the Circulation of the Blood, a learned account of
three theories on this matter which were in vogue at his time.
They are of importance, as showing that the fact was then
very clearly recognised, however dubious the explanation of it
might be. One party supposed that there was in each gland
a certain material stored up, which prevented the passage
through to itself of any substance that was not like it; just
as when a sheet of paper is steeped in oil, oil only will pass
through it, and not water. A second party, called the Chymical
party, supposed that there must be in the immediate
neighbourhood of each gland a subtle fluid or ferment, whose
tendency and office it was to form and separate from the blood
the materials which that gland had to secrete. A third set of
physicians armed themselves with mathematics and with the
newly discovered principles of Newton, and actually worked
out formulæ and equations wherewith to support their arguments.
They had strong and perhaps reasonable ideas as to
the definite shapes of atoms. They averred that each gland
was to be compared to a sieve or strainer, having in it pores
of a particular size and certain geometrical shape, and that
each secreted atom could only pass through a pore that would
exactly coincide in size and figure with itself.
The first two of these theories Dr. Pitcairn disputed, and
treated with high disdain. The third he accepted in a modified
form. He supposed that the vessels in the glands ended
in small open mouths, always circular, but differing in diameter
in different glands, so that each would only admit the
passage of a particle whose diameter approached a certain sum.
Thus he supposed that each secretion would consist only of certain
peculiar particles. Possibly Dr. Pitcairn forgot that small
particles would seldom hesitate to pass through large holes.
We may perhaps feel inclined to make light of these crude
speculations of the philosophers of the eighteenth century; we
may be disposed to smile at the idea of vessels with open
mouths, and of glands which are riddled with holes like the
buckets of the Naiades; but we must after all confess that if
at the present day we have swept away these notions, we have
certainly added nothing in their stead, nor can we explain
this matter at all more clearly than our predecessors a century
and a half ago.
The fact, however, is plain, however vainly we may try to
explain it. It is an established rule, to which there are few
exceptions, that each substance which is formed in the blood
and has to pass out of the body, tends to pass out through
some particular glands; that it is the particular function of
the kidneys to excrete water, urea, uric acid, and certain salts;
that it is the especial office of the bowels to excrete certain
effete matters and gases; and that it is the peculiar province
of the liver to excrete fatty matters, taurine, cholesterine, and
choleate of soda.
Water, being the necessary solvent of the solid matters in
all the fluid secretions, is secreted in greater or less quantity
by all the important glands. The kidneys are the chief emunctories
of water,—i.e. they have to separate it from the blood
when it has entered in an unnatural amount. But in the excretion
of water there exists a compensating relation between
the skin, kidneys, and bowels,—particularly between the two
former. So that when water is not properly excreted by the
kidneys, it may pass out by the skin, and vice versâ. It is
well known that this change may be determined by several
circumstances, particularly by the conditions of heat and cold,
or moisture and dryness. The relation between the function
of the skin and kidneys applies also to other fluid and solid
substances, as will be seen when we consider the medicines
which act upon these glands.
Now this law of selective secretion applies not only, as it
seems to me, to substances which in the course of nature are
formed in the blood, and have to be excreted from it, but also
to other matters which have been, as it were, accidentally introduced
from without, and which, being in the system, cannot
properly remain there. Thus it would apply to all medicinal
bodies which have passed from the stomach into the blood,
and which, not being natural constituents of that fluid, must
again pass out of it.
So that although it is often laid down that medicines acting
on the glands do so simply by passing along in the blood, and
stimulating them as they go by, I regard this as a needless
complication of the subject, and a thing which is wholly without
proof. In fine, I am brought to the opinion which I have
laid down in the Tenth Proposition, and which I have now to
establish as well as my space will permit. The affirmation
may be thus divided into minor propositions:—
m. p. 1.—That Eliminatives are medicines which pass into the
blood.
m. p. 2.—That they cannot remain there, but must pass out
of the body.
m. p. 3.—That in so doing, they tend to pass out by some
glands more than by others.
m. p. 4.—That the result of their passage through a gland is
to increase its secretion.
m. p. 5.—That they are of use when the state of the system
requires that the function of a gland should be
restored or promoted.
What I wish to prove is, that a medicine increases secretion
simply by being itself secreted; that while passing through a
gland it stimulates the secreting cells, and rouses them to a
proper performance of their natural function; that each
eliminative medicine has a tendency towards particular glands,
and increases the secretion of those glands; that thus, as far
as our information on the subject extends, we find that Cathartics
are excreted from the blood by the glands of the bowels,
and pass out with the fæces; that Diuretics are to be discovered
in the urine, Diaphoretics in the sweat, and those Expectorants
which are volatile may be detected in the odour of
the breath.
Any material which is naturally eliminated would act as an
eliminative medicine. Thus if a drachm of Urea be dissolved
in water, and injected into the veins of a dog, it causes copious
urination, which continues until the whole is excreted.
This well illustrates the argument.
Further, we find that when an eliminative medicine is
diverted from the gland by which it usually passes out, it no
longer augments the secretion of that gland. Dr. Ward gives
an interesting case of a woman who was never purged by
Castor-oil, but in whom the oil exuded from the skin, and
acted as a Diaphoretic. And it is, as I have said, well known
that the conditions of cold and exercise will cause a Diaphoretic,
in most cases, to act on the kidneys, because it is then
excreted by them. For the same reason, warmth, confinement,
and rest, will induce a Diuretic medicine to act on the
skin.
Thus if it be shown, on the one hand, that Eliminative medicines
themselves pass through the glands whose secretions
they augment; and, on the other hand, that when they do not
pass through them, they do not, as a general rule, augment
their secretion,—it may then fairly be presumed that they
operate by so passing through.
I assert, then, that medicines which stimulate secretions
are themselves secreted. But the converse of this—i.e. that
all medicines which are secreted at the same time increase
secretion,—though it holds good in the main, is not invariably
true. There are two chief exceptions to it. These are Astringents
and Hyperæmics.
When an Astringent passes through a gland, it tends, by
its natural force, to decrease secretion, and to cause constriction
of the ducts. Thus Uvæ Ursi may decrease the amount
of the urine, although it sometimes does the opposite; in
which case the eliminative may be said to surmount the astringent
tendency. So also Catechu, Kino, and Sulphuric
Acid, decrease the secretion of the intestinal glands. But
general Astringents are not always glandular Astringents.
Thus the mineral acids act as Diuretics.
By Hyperæmics I mean medicines which produce congestion.
Powerful Eliminatives do this when given in excess,
simply by exciting excessive action. Now it is a general
rule that congestion, however caused, diminishes the secretion
of a gland. Thus congestion of the liver produces jaundice;
congestion of the kidney, ischuria. After scarlatina, when the
kidneys are suddenly called upon to eliminate a morbid material
from the blood, congestion of the glands may be caused:
the urine is diminished, and dropsy results.
Cantharides and Turpentine are Diuretics. They increase
the urine when taken in moderate doses; but when in an overdose,
they diminish it, and may cause painful strangury, with
an almost total suppression of the secretion. The explanation
of such an action is obvious. Congestion is caused by the
excessive action. In the same way we find that a large dose
of Mercury, naturally a Cholagogue, may produce jaundice,
by causing congestion of the liver. This fact has been
observed by Dr. Graves, of Dublin.
In all cases, then, in which observations have been made,
we find that an Eliminative medicine is secreted by the gland
which is stimulated by it, and, in most cases, that a medicine
which is excreted by a gland tends to increase its particular
secretion.
Having made this general statement of the case, I must
attempt a more particular and detailed proof. I will treat
in turn of the above minor propositions, as applicable to the
following orders of Eliminative medicines:—
Class IV. Eliminantia.
Ord. 1. Sialagoga.
Ord. 2. Expectorantia.
Ord. 3. Cathartica.
Ord. 4. Cholagoga.
Ord. 5. Diaphoretica.
Ord. 6. Diuretica.
They are enumerated nearly in the order of the glands,
from above downwards, in the human body. I have not enumerated
Errhines, because the medicines which are used to
increase the nasal mucus are merely topical irritants, and
not true Eliminatives.
Of Emetics I have already spoken. Some are Neurotics,
acting from the blood on the nervous system; other are local
irritants. They also are not true Eliminatives.
Neither are Emmenagogues so; for the uterus is not a
gland. Some of these too are Neurotics. Most of them act
by causing a determination of blood towards the organ.
Cathartics do this by their action on the contiguous mucous
membrane of the intestines. (Vide page 102.)
These then are the six orders of Eliminative medicines. In
the first minor proposition it is stated that they pass into the
blood. This has already been in great part proved; for most
Eliminative medicines belong also to one or more of the preceding
classes, of which it has been shown that they pass into
the blood.
Thus Antimony, Mercury, Acids, Alkalies, Sulphur, the
Salts, etc., are Hæmatics primarily. The various volatile oils
and resins are more or less Stimulants. So also Alcohol and
Ether, as well as Camphor and others, are found among Narcotics.
Colchicum, Digitalis, Creosote, and Ipecacuanha, are
Sedatives. Many Eliminatives are certainly known to pass
into the blood, because they are subsequently found in the
secretions, as will be presently seen.
Secondly, these medicines cannot remain in the blood, but
must sooner or later leave it. If they remained, they could
not pass through the glandular cells. But if they pass out,
they must inevitably be excreted by them.
All those medicines must be secreted which have nothing
in the natural blood corresponding to them. This is the case
with most Eliminatives, and with all medicines except the
Restorative Hæmatics. And those Restoratives which act as
Eliminatives, such as Acids and Alkalies, do so because they
are introduced in so large a quantity that they cannot possibly
remain in healthy blood. Thus all these medicines pass
out through the glands.
Thirdly, we find that in so doing they tend to pass out by
some particular glands rather than by others.
In order to show this we may consider first the chief tendencies
of the great groups of Eliminative medicines; and
secondly, I shall endeavour, when considering the six orders,
to show that many of the medicines included in them have
actually been found in the secretions of the glands towards
which they tend. The first consideration will clear the way
for the second. What we have to ascertain is, that the principle
of selective secretion is generally applicable to Eliminative
remedies.
The most important of the substances which are used to
increase secretion may be divided chemically under the following
six heads, of all of which it has been proved that they are
capable of absorption. (Prop. II.)
1. Insoluble mineral substances.
2. Soluble minerals,—i.e. Acids, Alkalies, and Salts.
3. Ammonia and volatile oils.
4. Fixed acrid oils.
5. Resins and neutral acrid principles.
6. Soluble vegetable principles.
1. Insoluble mineral substances.—The chief of these are
Mercurials (Blue Pill and Calomel,) Iodine, and Sulphur.
They are all more or less changed during the process of absorption,
as they have to be reduced to a soluble condition.
They stimulate secretion generally; but Mercury particularly
tends to the liver, bowels, salivary glands, and skin; Iodine,
to the kidneys, and to the salivary and mucous glands; Sulphur,
to the skin.
2. Soluble mineral substances.—Acids, Alkalies, and Salts,
may pass off by any of the fluid secretions. The chief of these
secretions are the sweat, the urine, and the secretion of the
bowels. The sweat is only fluid when the skin is kept covered
and very warm. In other cases the choice lies between the
kidneys and the bowels. The kidneys are the grand purifiers
of the blood, so that most of the substances which stimulate
the other glands may occasionally pass off in the urine. And
soluble minerals, which require some amount of water for
proper solution, would tend for this reason towards the most
fluid of the secretions.
But there are some other things which counter-balance this
tendency. The constitution of the urine is such that it cannot
safely be disturbed to a very great extent. If there be
much excess in it either of acid or of alkali, a deposit is occasioned.
Dr. Bence Jones found that Sulphuric acid never
passed out in the urine in any quantity. We find too that
when a certain quantity of a saline is administered, too great
to pass off readily by the kidneys, it prefers to act on the
bowels. It is more likely to be diuretic if much diluted with
water; but this is not the only directing cause, for a very large
quantity of a saline will prove purgative even when largely
diluted. (Vide Prop. II.) Thus the general rule is this:
soluble minerals are in small doses Diuretic, in large quantity
Purgative. This applies more especially to salts; for mineral
acids act as astringents on the bowels,—and mineral alkalies,
being corrosive, cannot be given in large doses.
3. Ammonia and volatile oil.—The laws of endosmosis
favour the passage of soluble substances through to a liquid
secretion. They are dissolved and carried away on the other
side of the membrane through which they pass. In the same
way it appears that volatile substances may dissolve in, and
be carried away by, air. Thus they have a tendency towards
the aeriform secretions. These are,—the expired air, or the
secretion of the air-cells of the lungs,—and the ordinary cutaneous
transpiration. While passing through the air-cells,
these matters stimulate the secretion of the lining mucous
membrane. They cause a morbid secretion of this surface to
be replaced by a more natural one. Thus Ammonia and volatile
oils are Expectorant and Diaphoretic. They may all
pass out in the urine, but do not especially tend to do so,
with the exception of some that are acrid, and approach to
the nature of the resinous group. Turpentine, Juniper, and
Copaiba, are Diuretic.
4. Acrid fixed oils.—Such are Castor and Croton Oils; they
are Purgatives, passing off by the bowels.
5. Resinous and neutral acrid principles.—These are soluble
in alkalies, and thus partly absorbed in the intestinal canal.
Most of them are Cathartic, whether introduced into the stomach
or injected into the veins. Such are the resins of Scammony,
Jalap, and Gamboge, and the principles of Colocynth
and Elaterium. Some few of them are Diaphoretic, as Guaiacum
and Mezereon. Some again are Diuretic, especially
those which are liquid or associated with a volatile oil, which
is the case with Copaiba, Cubebs, Cantharides, and others.
6. Vegetable principles soluble in water.—Most of these are
Diuretic; as are the Vegetable Acids, and the Alkaloids of
Digitalis, Tobacco, and Colchicum. So also are the principles
of Broom and Sarsaparilla. The Emetine in Ipecacuanha,
and the Morphia in Opium, act on the skin. Aloesin, the
principle of Aloes, is purgative. So is Cathartin, the soluble
acrid principle of Senna.
Having thus briefly sketched out the particular tendencies
in the operation of the groups of medicines which act on the
glands, it remains for me to say that in very many cases these
medicines have actually been proved to pass out of the body
by the glands whose secretions they tend to increase. Whenever
we are in a position to inquire into the facts by chemical
or other means, we find that the Eliminative medicine is itself
contained in the secretion which is augmented by its action,
and that when the secretion upon which it usually acts
is not augmented, the medicine has passed off by some
other secretion instead. There are doubtless many cases in
which no inquiry of the kind has been yet made; but it will
be seen when we consider separately the Eliminative orders,
that all that is known on the subject is in favour of the above
statement.
Assuming, then, the third and fourth minor propositions
together, we conclude that Eliminative medicines, which must
pass out of the blood, tend to pass out by some glands more
than by others, and that the result of their passage through
a gland is to increase its secretion.
They do not exert a blood-influence, nor do they act on the
nervous functions; but they operate on those obscure vital
forces by which secretion is directed and controlled.
The fifth minor proposition treats of the application of these
agents in the treatment of disease. They are of use when it
is requisite that the function of a gland should be restored or
promoted. There is scarcely any disease in which some or
other of them may not be of service. Their remedial applications
are many and important.
Eliminatives are used to restore the function of a gland
when impaired. With this view, Cathartics are employed in
constipation, Diaphoretics for dryness of skin, Cholagogues
in torpid states of the liver.
They may eliminate a poison or morbid material, and thus
resolve a disease. This probably is the rational explanation
of the use of Diaphoretics and Diuretics in Fevers, Gout, and
Rheumatism, and of purgative medicines in a great number
of disorders.
We may, by an action on one gland, be enabled to replace
the function of another gland. The amount of each secretion
bears more or less an inverse proportion to that of other secretions.
Thus when one of them is unduly copious, we may
diminish it by stimulating the formation of another. In other
cases the reverse condition may occur; one of the secretions
may be diminished or suppressed by a cause over which we
have no control, and the matters which should be contained
in it may be left in the blood, causing various mischief there.
Here again, by increasing one of the other secretions, we
may replace the function of the diseased gland, and cause
the elimination of these products from the body by another
channel.
Fourthly, Eliminative medicines may be of service by draining
away from the blood fluid and solid matters. The first
result of their action is to stimulate the proper secretion of a
gland; but when it is pushed to a further extent, they may
actually case the excretion of some of the natural constituents
of the blood. Thus by an action on the skin or the kidneys,
we may cause a copious evacuation of water, holding in solution
saline matters. By increasing the secretion of the intestinal
glands, we may cause the albuminous serum of the blood
to be poured out into the cavity of the bowels. Thus it is
that all Eliminatives are more or less antiphlogistic. Cathartics
are especially so. Their influence, when carried to excess,
is analogous to that of blood-letting. As evacuants, Cathartics
are employed in diseases of the brain especially; and
Diuretics are made use of in dropsies to diminish the amount
of fluid in the blood, and in this way to promote absorption.
So much having been said of the general action of Eliminatives,
we proceed to make a few remarks on the individual
orders of medicines which are included in this division. Those
substances can alone be properly included in these groups
which really act on the principle of elimination, as above defined.
There are in many instances other medicines which
are found to increase secretion in an indirect way.
Ord I. Sialagogues.[45]
This name is applied to medicines which in various ways
increase the quantity or promote the excretion of the saliva.
They are seldom employed as remedial agents; for the excretion
of saliva is constant and very rarely suppressed, and it is
so small in quantity, and so great a source of inconvenience
when increased to any amount, that Sialagogues can never be
employed as general evacuants. There are two kinds of Sialagogues.
Any solid substance which excites the mucous surface of
the mouth, as the natural food,—or even the act of mastication
alone,—will suffice to bring on the secretion of saliva. An
irritant substance, as Ginger, or Pyrethrum, tends especially
to cause this secretion when masticated. Catechu and Betelleaf
are chewed for this purpose by the natives of the East.
Such a stimulation of the salivary glands may be advantageously
resorted to on the counter-irritant principle in obstinate
cases of head-ache, ear-ache, or tooth-ache, or in neuralgic
or chronic rheumatic affections of the face.
When the quantity of the saliva is thus increased, it should
not be rejected, but always swallowed when possible; for this
secretion is apparently useful in the stomach, and in some
way essential to the proper carrying on of the digestive process.
The chewing of Tobacco, Betel, and other substances,
is frequently found useful by sailors on long voyages, and is
adopted as a preservative against the dysentery and diarrhœa
with which they are so often affected. This advantage is to
be attributed to the increase in the salivary secretion. On
the other hand, we find that the practice of constant spitting
is productive of very injurious effects; and it is more than
possible that the pale faces, lank figures, and dyspeptic maladies,
which are so common among the American people, may
be due in part to the prevalence of this habit among them.
These topical irritants and masticatories are not true Eliminatives.
There are also some medicines which by another
topical action may occasionally produce salivation. These are
Sedatives. Hydrocyanic acid, Digitalis, and nauseant medicines,
may act locally so as to paralyze the muscular fibres
by which the constriction of the salivary ducts is maintained,
and thus allow the secretion to pour out uncontrolled into the
cavity of the mouth.
True or Eliminant Sialagogues.—These are medicines which
are actually excreted from the blood by the salivary glands,
and which increase their natural secretion while passing
through them. Mercury is the most important of these. When
given to a considerable extent, it causes soreness and redness
of the gums, and profuse salivation. It probably increases
the amount of saliva even before this soreness is produced.
It is not given for the purpose of producing salivation, but in
cases where the full action of Mercury is desired this symptom
is made use of as a sign that the medicine has taken full effect
upon the system. If we permit it to be carried to too
great an extent, sloughing of the gums and other dangerous
results may be produced.
In some rare cases salivation has followed the administration
of Iodine. It is also not an unfrequent symptom of
chronic poisoning by Lead. In cases of salivation by these
Eliminative medicines, the substance which has caused the
increased secretion may be, and has been, discovered in the
saliva by chemical tests. They are therefore true Sialagogues.
Ord. II. Expectorants.
This term, when taken in its widest sense, is applied to all
medicines that cause the evacuation of mucus from the secreting
surface of the respiratory tubes and cavities. They
help the natural process of Expectoration.
Many medicines are capable of acting indirectly as Expectorants.
Any thing which causes cough, as an irritant gas,
will do it. So will any thing that thins the mucus when thick
and viscid,—e.g. the inspiration of the vapour of hot water.
Special Sedatives, which control the function of the Vagus
nerve, are especially notable as indirect Expectorants. Such
are Antimony and Ipecacuanha. By diminishing the morbid
irritability of the pulmonary surface, they prevent the continued
secretion of mucus. By allaying a spasm of the small
bronchial tubes, and controlling the nervous sensation of want
of breath, they may promote the evacuation of that which is
already secreted.
Opium and Stramonium, classed among Narcotics, depress
the function of this nerve as well as the nervous forces generally.
So do other medicines similar to them. Opium in
small doses allays irritability and diminishes spasm, and is
then an indirect Expectorant; but in large doses it acts so
powerfully as to render respiration difficult and expectoration
impossible. Its use therefore demands great caution.
True Expectorants.—The action of Antimony and Ipecacuanha
upon the secretion of bronchial mucus is of so specific a
character as to render it highly probable that these medicines
add to their neurotic influence a true eliminative agency. We
are as yet unable to decide whether or not they are ever secreted
by these mucous glands, because not only is the analysis of
the mucus a matter of difficulty, but hitherto no investigation
of the matter has been made. Squill also is probably an Eliminative
Expectorant.
Many of the true Expectorants are volatile and odorous in
nature. All excreted substances have to pass by an endosmotic
process through a thin animal membrane. And it is
necessary before they can pass, that there should be on the
other side of this membrane something which is capable of
dissolving them. Diuretics are soluble in water, and they
pass through into a watery fluid. But these Expectorants,
whether they pass through the mucous glands, or immediately
through the thin wall of the lung-cell, are brought directly
into contact with air. And in this air these volatile matters
are soluble, and are carried away by it.
This appears to be the reason why the Eliminatives which
are volatile in nature tend particularly to act on the two aeriform
secretions,—i.e. on that of the air-cells of the lungs, and
on the common cutaneous transpiration. For though the
glands of the mucous membrane of the lungs secrete mucus,
yet the chief object of the terminal portion of that membrane
is to absorb and secrete the gaseous matters of the blood.
The following are the chief volatile Expectorants, the odours
of which have been clearly detected in the breath of persons
to whom they have been administered:—Turpentine, Camphor,
Alcohol, Ether, and the volatile oils of Onions, Fennel,
Asafœtida, Carraway, Cinnamon, and Anise.
These medicines, and others like them, are thus excreted by
the air-cells or mucous glands of the pulmonary surface, and
while thus passing through they stimulate the latter to a right
performance of their function. When, as in the case of Bronchitis,
the secretion of mucus is increased in amount, or deteriorated
into a purulent matter, they may be of service by
causing the healthy secretion to replace the diseased one.
Expectorants are very uncertain agents. The reason of this
is, that the pulmonary glands are not naturally intended to
act as emunctories, or dischargers of morbid matters from the
blood, and thus are less prone to be excited by Eliminative
medicines than other glands whose proper office is one of
general elimination. And yet we find that the effete gases
which should be excreted by the bowels are sometimes voided
by the lungs in case of aggravated dyspepsia, causing tainted
breath. Just so may other adventitious elements of the blood,
as these volatile medicines, be sometimes excreted by the pulmonary
membrane. But they may often pass off by the skin
or by the urine, and would not then act upon the lungs at all.
For the same reason that the lungs are not general emunctories,
and cannot be made use of to produce a wholesale evacuation
from the blood, Expectorants are of no use as general
Antiphlogistics. In this they differ from the four remaining
groups of Eliminatives.
They are only employed in pulmonary disorders, where we
desire to influence the amount or character of the mucous
secretion, when the mucous membrane is inflamed or irritated.
In old and chronic cases of Bronchitis the stimulant volatile
Expectorants are the most applicable. Tartar Emetic and
Ipecacuanha are appropriate in acute and inflammatory cases,
because they exert a nauseating and depressing action. They
are sometimes given in sufficient dose to act as Emetics; for
the act of vomiting mechanically assists the expulsion of mucus
from the air-cells and passages by causing straining and
compression of the lungs.
Ord. III. Cathartics.
Cathartics are medicines which tend to increase the secretion
from the inner surface of the bowels, and promote the
natural expulsion of the contents of the intestinal tube. Of
these two operations the first only is an action of elimination,
and the second is an accompaniment to it. The first can
hardly take place without being followed by the second; but
in some few cases the second action alone may be produced.
The subject of the application of Purgative medicines is so
extensive, that it is impossible for us now to inquire into it at
any great length. It should however be observed, that they
are the most powerful and the most useful of all Eliminative
medicines. The fæces consist partly of the undigested matters
of the food, and partly of a secretion which is poured out
by the inner surface of the bowel. (Vide infra.) The majority
of Cathartics increase this secretion. Whatever notion
we may adopt as to its physiological purpose, it appears that
we can act upon this intestinal function with ease and certainty
in the great majority of cases. The surface of the
intestine, covered as it is with a closely packed glandular
apparatus, forms in the aggregate the largest secreting organ
in the body. From the measurements made by Meckel, it
appears that it covers a space of 1400 square inches. By the
administration of a medicine of this sort, we are enabled to act
upon this surface, producing simply an increase of the fæcal
secretion, or causing, when the action is violent, an outpouring
even of the fluid part of the blood. When this secretion is
stopped, we may cause it to reappear; when another secretion
is repressed, we may be enabled to replace it by this; and in
the treatment of plethoric or inflammatory disorders, we find
among Cathartics the simplest and readiest of antiphlogistic
or evacuant medicines. For they possess these great advantages,—that
they act with certainty, and produce a notable
effect.
All medicines which by a mere external action augment
the secretion of the bowels, or promote its evacuation, must
be regarded as indirect Cathartics, for they do not operate
on the eliminative principle. An outward irritation of the
mucous membrane is sufficient to excite the peristaltic contraction
of the bowel, and may even increase the secretion of
that mucous surface by a reflex nervous action, in the same
way that an irritation of the mucous lining of the mouth will
cause the secretion of the saliva. All substances which, after
being taken into the stomach, are not absorbed, which are
thus pushed onwards along the inner coat of the intestine,
and by their mere accumulation excite its muscular contraction,
must operate more or less as indirect purgatives. Of
such a nature are the ligneous fibres of vegetables,—the bulky
pulp of fruits, as in Prunes, Tamarinds, and Cassia,—and the
husk of wheat in brown bread,—all of which are known to
act as laxatives. Very different from these in the intensity
of their action are the resinous Cathartics, as Scammony and
Gamboge, which, though capable of absorption, appear also to
act in some cases by an external irritation of the intestinal
surface. They are also true Eliminatives, for they are known
to become absorbed; they may thus act in a double way, both
directly and indirectly. (Vide p. 96.) In small doses it is
probable that they are simply Eliminatives, but when given in
large doses they may add to that an irritant external action,
and produce a very powerful or even dangerous effect.
True Cathartics.—These are very many in number. At
whatever part of the system they are introduced, their action
is the same. If one of them be injected in solution into the
veins, or absorbed from the surface of the skin, it passes at
length to the intestinal canal, is excreted by the glands of the
mucous surface, and causes purging by augmenting their
natural secretion. When given as a medicine, the Cathartic
is first received into the stomach. It is capable of absorption,—whether
it be soluble in water, or in acid, or be of an
oily or resinous nature,—as was ascertained in the consideration
of Proposition II. It is absorbed; and passes along in
the circulation. But it is unnatural to the blood, and cannot
remain in it; so that it is at length expelled by the eliminative
force at the lower part of the intestinal canal, at a part
which is more active in excretion than in absorption, though
not very remote from the absorbent surface at which the
remedy first entered.
Cathartics may be advantageously divided into three groups:—1. Mercurials,
which tend to increase all secretions; 2.
Some resins, oils, and acrid principles, which tend especially
to the bowels; and 3. Salines, when given in such amount
that they cannot pass off by the kidneys.
Mercurials, being also Cholagogues, are especially useful in
bilious habits. When given to act on the bowels, a Mercurial
is generally conjoined with another purgative, that it may not
do damage in the system by remaining in the blood.
In the second group the great majority of Cathartics are
included. They vary very much in the intensity of their
action. Some are mild, and may be administered in inflammations
and fevers, or even in pregnancy, where a gentle
action is required; others are powerful and drastic, and may
cause serious congestion, or even inflammation of the bowel.
All the resins and acrid principles are more or less heating,
and should be administered very carefully in febrile states of
the system. Of the resins, Jalap is comparatively mild, and
may be given to children without risk; while Scammony,
Colocynth, and Gamboge are more drastic. Of the oils,
Olive-oil is merely laxative; Castor-oil may be given in all
cases without danger; but Croton oil is a dangerous hydragogue
Cathartic. Of the medicines which owe their efficacy
to acrid principles, there are some which are mild in operation,
and whose principles are soluble in Water. Such are
Rhubarb, Aloes, and Senna. Senna is somewhat irritant.
Aloes appears to act on the lower part of the intestine, and
is therefore objectionable in cases of pregnancy or of uterine
disorder. Hellebore is a more powerful acrid, but is now
seldom used. Elaterium is the most potent purgative known.
In cases of dropsy, when all other medicines have failed, one-twelfth
of a grain of this substance has been known to produce
a copious evacuation.
Salines, i.e. salts of the alkaline and earthy metals, are all
more or less purgative when given under certain conditions.
Under other circumstances they may pass off from the body
by the kidneys or the glands of the skin. The circumstances
which determine the excretion of saline matters appear to be
simple in nature. In the common condition of the body it is
not possible for the secretion of the skin to be very largely
increased, or rendered fluid. Suppose, then, a soluble saline,
as the Sulphate of Soda or Magnesia, or Tartarized Soda, to
have obtained entry into the blood, it has the choice of being
excreted by the kidneys or the bowels. The alternative appears
to depend mainly upon the amount of the dose. A
small quantity may pass in the urine, and will not produce
purging. But a large quantity cannot so pass; it is excreted
by the glands of the bowels, and acts as a Purgative. It has
been supposed by some that a saline solution proves Purgative
or Diuretic according to the degree of its dilution only.
This matter we have already considered at some length; and
the reasons which have induced me to arrive at a contrary
conclusion have been detailed under the head of Proposition
II.
Salines are hydragogue. Requiring water for their proper
solution, and having further a great affinity for it, they convey
a large quantity of the aqueous part of the blood with them
through the glands of the bowels. When their action is very
powerful, some of the albumen of the blood may be purged
away along with this. This may also take place with the
drastic resinous Cathartics. But the latter are much more
violent in their action, producing a degree of griping and irritation
which is dangerous in febrile cases. Salines, on the
contrary, are cooling, and mild in their operation. They are
appropriate in inflammations, not only for this reason, but
because, while passing through the blood, they exert in it, as
we have already seen, a mild action of an antiphlogistic
nature. (Vide page 188.)
When the vegetable salts of the alkalies are given in diuretic
doses they are decomposed into carbonates while in the system.
This does not appear to be the case when they are
given in such quantity as to pass off quickly by the bowels.
These various Cathartic medicines are affirmed to act on
the eliminative principle: it follows then that they must themselves
pass out of the body along with the secretion which is
augmented by their action. It is natural that the fæces should
have been less examined than other secretions. The resins of
Jalap, Scammony, and other such substances, are affirmed to
pass out along with them. Of the passage of saline Purgatives
we have an indirect proof; which is, that after their
administration the amount of saline matter in the urine is not
materially increased. Castor-oil is seen in the evacuations,
sometimes little altered, at other times in the form of a solid
fatty substance. M. Lehmann has detected Mercury in the
fæces, whenever it was given as a Purgative, and whatever the
colour of the evacuation. When combined with a sufficient
amount of Opium, it neither acts as a Purgative, nor does it
pass out by the bowels; and it has therefore in that case a
better opportunity of exerting its operation in the blood. We
always find that when a Cathartic passes off in some other
way than by the glands of the bowels, it fails to produce
purging. Thus a copious dilution with water may sometimes
cause it to be excreted by the kidneys, which are the natural
emunctories of water. In some persons that are wont to perspire
very freely it is difficult to produce purging. The case
related by Dr. Ward of a woman with whom a dose of Castor-oil
was seen to pass off by the skin, and invariably failed to
act on the bowels, is an extreme instance of this kind.
Of what use and intention, we may now venture to ask, is
this intestinal function, the continual maintenance of which
in a healthy condition is found to be so essential?
It was some time ago supposed that the fæces consisted
simply of those parts of the food which remained unabsorbed,
and that all Purgative medicines alike acted by exciting the
peristaltic motion of the bowels, and causing thus the ejection
of these undigested matters. Such an opinion is now rarely
maintained. Although very little is known of the separate
functions of the glands of the intestinal mucous membrane,
yet it is generally supposed that the fæcal matters consist in
great part of excrementitious substances which are separated
by their means from the blood. The excretion of fæces continues
when no food is taken. It is known to go on with
starving men, and with patients in fever. Liebig argues for
the secretion of the greater part of the fæces, on the ground
that they contain nitrogenous matters, whereas all the nitrogenous
parts of the food should be absorbed for the purposes
of nutrition. Thus these are probably the excreted products
of changes in the system, which it is the province of the bowels
to separate from the blood. (Anim. Chem. p. 156.) The
odour of these matters is partly owing to sulphuretted hydrogen,
or hydrosulphate of ammonia, both of which are the products
of animal decomposition. On account of their presence
a black colour is communicated to the fæces by the internal
administration of the salts of Iron.
It seems to me to be probable that the constituents of the
living as well as of the dead body are constantly subjected to
the control of chemical laws, and undergoing destruction and
change. Some products of these changes in an early stage
are eliminated in the urine; but in great part they go on to
actual putrefaction. The products of this, which are of an
offensive character, are apparently discharged from the body
through the follicles and glands of the intestines. We find
that this decomposition is promoted and accelerated by heat,
in the same way as with dead animal matter. For this reason
it appears that the natives of warm climates excrete a much
larger quantity of fæces than the dwellers in colder latitudes;
and they are also more subject to Dysentery, Diarrhœa, and
Cholera, on account of the extra work thrown upon their intestines.
A similar explanation may perhaps be assigned to a
curious fact noticed some time ago by Mr. Curling—viz., that
acute ulceration of the duodenum is a frequent consequence of
severe superficial burns. A quantity of gangrenous or decomposing
matter may in such a case be carried from the
surface into the circulation.
This blood-decomposition, which I suppose to be always
going on, may be accelerated by the action of certain morbid
poisons or processes. The secretion of the bowels is then increased,
and by the excitement or over-work a diseased condition
of the intestinal surface may be established. In this
way the diarrhœa and ulceration of the glands in Typhoid
fever may be accounted for. The air of a dissecting-room, or
the neighbourhood of a noxious sewer, is apt to bring on diarrhœa
by exciting a putrefaction of the blood. Severe bodily
exercise, as a long walk, may cause it, by increasing the waste
of tissue. We find that constipation is commonest in youth,
when nutrition is most active; and diarrhœa most frequent in
old age, when waste and decay go on the fastest.
When these decomposed matters which should be excreted,
are retained in the blood, as is the case in constipation, they
affect very injuriously both the brain and the system in general,
causing torpidity of the one, and in the other favouring
the progress and development of every description of morbid
action. It is by cleaning such matters out of the blood, as
well as by their antiphlogistic or evacuant action, that Cathartics
become useful in so many diseases, and particularly in
disorders of the brain. It would seem that the substances
which would be eliminated by the bowels have, when retained
in the blood, a peculiar action in the aggravation of disorders
of this latter organ. Thus from very early times the
exhibition of drastic purgatives, particularly Hellebore, has
been strongly recommended in cases of mania.
But there is scarcely any disorder in which there is not, in
some way or other, a deranged condition of the intestinal
function, and in which, therefore, the judicious employment of
purgative medicines is not at some time necessary. Either
there is constipation, in which case there is a danger of the
fæcal matters being retained in the blood; or there is diarrhœa,
which is probably due to an over-formation of these
materials in the system, and an attempt of nature at their
evacuation. In each of these cases Cathartics may be necessary.
The first condition is the more obstinate of the
two; the second the more immediately dangerous. Some
general indications for their treatment may be alluded to.
In the treatment of constipated habits it is better to keep
up a constant and gentle action on the bowels than to give
violent doses occasionally. A condition of this sort may
sometimes co-exist with comparative health, and may then
often be remedied by a slight alteration in diet, and the prescription
of such kinds of food as are more relaxing in their
nature than those hitherto taken. Dr. Hamilton, in his work
on Purgative Medicines, states that when they are given in
constipation he has found that they become more and more
powerful, and may be taken in smaller and smaller doses the
longer they are continued. This is probably the case with
such as Castor-oil, Scammony, and Jalap, which are simply
cathartic in their action. But others, such as Rhubarb and
Aloes, contain a bitter and astringent matter along with the
purgative principle, and though they first act upon the bowels
tend for this reason in the second place to confine them.
Thus while the former are best in cases of constipation, the
latter are preferable in diarrhœa, as they supply us then with
the very action which we require.
There are two ways, apparently opposite and inconsistent,
of treating a flux from the bowels. We may try to encourage
it by Purgatives; or attempt to suppress it by Astringents.
Thus we may treat a common diarrhœa by Castor-oil, or by
Sulphuric Acid. In dysentery we may give Calomel, or
Catechu. Even in Cholera some recommend Opium, while
others have employed Croton-oil. In the most obvious case,
i.e. in simple diarrhœa, it is apparent that both plans are appropriate,
but at different periods of the disorder. The symptom
depends upon the fact of something being formed in the blood
which ought to be excreted from it. Probably it is an excess
of that material which is ordinarily excreted by the bowels.
Its passage out by a natural effort causes at first a simple increase
of the usual evacuation. It is at this time that we
should give a Purgative, to favour the natural excretion, and
thus, if possible, to put an end to the disturbance. But sometimes
it fails to do so. The matters to be excreted are irritating,
and such an excitement may be caused in the glands
by their passage out, that even after this necessary secretion
an inordinate and unnatural flux may be maintained. When
the symptom is thus inveterate, and refuses to yield to a brisk
Cathartic, it is advisable to resort to Astringents, in order to
put a speedy stop to the too copious secretion. To do this in
the first instance would have been wrong, except in special
instances,—as in the diarrhœa which is the forerunner of
cholera, when Astringents should be used from the first.
In some febrile and plethoric cases it is difficult to obtain
the full action of a Purgative. This is because the absorption
of the medicine is prevented by the pressure on the vascular
system, and without this absorption the proper action of the
Purgative cannot take place, for it has no opportunity of passing
out of the blood through the glands of the bowels. In
such instances it is well to combine the Cathartic with a small
dose of Tartar Emetic or Ipecacuanha, which by its nauseant
operation may diminish the vascular pressure, and thus favour
the necessary absorption. The action of a Cathartic itself
favours absorption, by draining away the fluid part of the
blood, and so diminishing the tenseness of the vessels.
Ord. IV. Cholagoques.
Medicines which are thought to stimulate the action of
the liver, and to promote the excretion of bile, are called
Cholagogues.
There is no doubt that the function of the liver, regarded
simply as a gland, is of great importance in the animal economy.
We know that certain matters are excreted from the
system by that organ, which, when allowed to remain in the
blood, as in the case of jaundice, are found to be hurtful. Also
it appears that certain other parts of the bile are secreted or
formed by the same gland, for the purpose of being re-absorbed
into the blood from the intestine, and that they serve
some useful purpose in the processes which go on in the circulation.
(Vide p. 137.)
A disorder of the liver by itself, i.e. unassociated with diseases
of other organs, is comparatively uncommon. A failure
in the secretion of bile is evidenced more or less by the well
known icteric symptoms. Jaundice is often caused by an
obstruction in the hepatic ducts. In such cases it is worse
than useless to urge the liver to an extra formation of a secretion
which can find no outlet. But other cases, in which the
discoloration of the skin is in general incomplete, may be due
to torpidity, congestion, or chronic inflammation of the organ.
In such instances Cholagogues may be cautiously used; but
when there is acute inflammation they may do harm; and
when there is a probability of structural change in the liver,
they may be useless.
The great majority of intestinal diseases, as also of chronic
blood-disorders, are associated with a torpidity or derangement
of the function of the liver. We find this to be the
case with diarrhœa and constipation, with dysentery and
cholera; as well as with ague and remittents,—gout, and
rheumatism,—Phthisis, and scrofula. In all of these diseases
it is of great importance to attend to the state of the liver. I
have already stated that Quina and other Tonics are of very
particular use in such cases of disorder of the hepatic functions,
and have attempted to discover an explanation of this
fact (p. 142.) But we are at present concerned with medicines
which tend immediately to increase the secretion of bile.
They are more or less applicable in all the disorders which
have just been enumerated. All Cathartic medicines act as
indirect Cholagogues. This is particularly the case with the
drastic purgatives. There appears to be a vital connexion
between the action of the intestinal canal and that of the
liver, so that any process going on in the one will excite the
function of the other. Thus the bile is poured out during
the process of digestion; and the peristaltic motion and extra-secretion,
produced in the bowel by the action of a purge,
causes likewise a sympathetic formation and excretion of bile.
It is supposed by some that this result is due to an irritation
of the orifice of the hepatic duct in the duodenum, produced
by the purgative medicine. We must either suppose the
stimulus of the food, which produces the same effect, to
operate in the same way,—or reject such an explanation as
superfluous, which appears to me the better alternative. For
it is probable that the action of a Purgative is not at all
exerted in the duodenum, but that it is actually absorbed
there, and works out its operation in the lower part of the
small and in the large intestine.
True Cholagogues.—We are not well informed as to the
exact number of medicines which pass out into the secretion
of bile, and act thus on the true eliminative plan. But there
is no medicine which is of such great and universal utility in
all liver diseases as Mercury,—in its various forms. Mercurials
increase more or less all secretions; and even if we had
no direct proof of their action on the liver, we might almost
have affirmed that they especially increased the secretion of
bile, from the obvious way in which bilious symptoms yield
to their action. But we have a direct proof of this. M.
Buchheim has made some careful experiments on a dog.
Having given it Mercury, he cut down upon the hepatic
duct, observed and collected the secretion, and subsequently
analyzed it. He found that the bile was increased, and that
Mercury was contained in it. (Vide p. 275.) Certain other
purgative medicines are popularly, and perhaps correctly,
esteemed as specific Cholagogues. These are Rhubarb and
Aloes. Taraxacum is also thought to act upon the liver.
But of the true eliminative action of these medicines we have
no proof.
It is probable that alkalies and fatty matters may act in
certain cases as true Cholagogues, for they are both contained
in the natural secretion of bile, and therefore likely to pass
into it.
In many cases of debility, and even of Scrofula, small doses
of Mercury may act efficiently as tonics, by stimulating the
function of the liver, which in such instances is generally
deranged.
Ord. V. Diaphoretics.
These are medicines which tend to promote the secretion
and exhalation from the surface of the skin. Of the matters
which are given off from the surface of the body there are
three kinds. Water in the state of insensible vapour, and
volatile matters, are continually exhaling from the skin at all
points, and pass unnoticed into the atmosphere around. The
liquid sweat, which in the ordinary state of the body is only
given off in sufficient amount to prevent the skin from becoming
over-dry, is secreted by the sudoriferous glands, whose
ducts terminate in large numbers on the surface at every part.
There is in the third place an oily material, formed for a
similar purpose by the sebaceous glands, which are widely
distributed, but fewer in number than the last. Diaphoretics
seem to increase only the first two kinds, viz., the aeriform
transpiration, and the liquid sweat; and they act upon these
in a varying proportion. In the consideration of this order
we have not only to bear in mind the distinction between
these two kinds of diaphoresis, but to note further the important
relations existing between the action of these medicines
and the state of the atmosphere, the condition of the body,
and amount of other secretions.
In all relaxed conditions of the general system, the amount
of the perspiration is apt to be increased. This is especially
evident in the weakness which follows a paroxysm of simple
fever. The force of the heart is weakened, the tone of the
capillaries impaired,—and by these conditions absorption is
favoured, and the amount of fluid in the blood increased. At
the same time the muscular system is relaxed, and the sudoriferous
ducts being thrown open by the diminished contraction
of the involuntary fibre that surrounds them, the excretion of
the sweat is favoured, and the watery parts of the blood are
poured out through the skin. This general relaxation precedes
and follows the act of vomiting, as induced by a dose of Tartar
Emetic or Ipecacuanha. Thus these medicines act indirectly
as Diaphoretics, when given in emetic doses.
True Diaphoretics.—The following groups of medicines
may be briefly noticed as tending to act as Eliminatives on the
glands of the skin. Five divisions may be made:—1. Salines
and diluents, under certain conditions; 2. Volatile substances
which are soluble in air, as Ammonia, volatile oils, and Alcohol;
3. Certain acrid matters, as Guaiacum; 4. Certain
Narcotics, as Opium and Camphor; 5. Antimony, Mercury,
and Sulphur.
These Diaphoretics are all more or less uncertain in their
action, as we have seen to be the case with Expectorants.
There are two causes of this uncertainty. In the first place,
the secretion of sweat, like that of the lungs, cannot be considered
as a common emunctory. There are hardly any solid
matters in it which are not also contained in the urine, and
commonly excreted by the kidneys. It is only in special
cases, or when there is a fault in the normal formation of urine,
that the skin is called upon to eliminate materials from the
blood.
In the second place, there are certain atmospheric and other
conditions which promote the secretion of sweat, and certain
others of an opposite nature which tend to retard it, and to
divert into another channel the aqueous materials which should
pass into it. With regard to the state of the atmosphere,
warmth favours diaphoresis, cold repels it. Warm dry air,
especially when in motion, promotes the aeriform transpiration,
by favouring evaporation. Moist air, which hinders
evaporation, promotes liquid sweating. Very active exercise,
with the surface warmly clad, produces liquid perspiration.
Moderate exercise, with a cool surface, favours diuresis. The
recumbent posture, and sleep, promote diaphoresis; the erect
posture and wakefulness, diuresis. Thus when it is required
to produce sweating, the patient is ordered to lie in bed, to be
covered warmly, and to compose himself to sleep. Any thing
which keeps the surface of the skin unnaturally warm, as a
hot-air or hot-vapour bath,—or thick flannel clothing, which
is a non-conductor of heat,—tends powerfully to cause diaphoresis.
So does friction, which stimulates and dilates the
external capillaries.
So far the conditions of sweating and of diuresis are nearly
opposite. But this is not the case with the medicines which
are used to cause them.
Diluents, and salines soluble in water, form the first group
of true Diaphoretics. Water promotes alike the function of
the skin and of the kidneys; and it is only by a regulation of
the circumstances mentioned above that it can be diverted
from the latter towards the former. Diluent drinks are indispensable
adjuncts to a Diaphoretic regimen. Salines also
tend naturally to pass off in the urine, when in small doses;
but when in large amount, by the bowels. A saline, being
soluble in water, cannot pass out except into a fluid secretion;
so that a saline diaphoretic should be given in a moderate
dose, and to secure its action the skin should be kept covered
and warm, and the patient in a recumbent posture. The
medicine will then pass off into the liquid sweat, as it otherwise
would have passed into the urine.
Volatile Diaphoretics may increase the cutaneous transpiration,
and pass off by the skin, without the production of sensible
liquid sweating. For being soluble in air, and capable
of being carried away by it, they therefore tend especially to
the two aeriform secretions, i.e. those of the lungs and of the
cutaneous surface. (Vide pp. 278, 285.) Ammonia and its
various salts are very useful as Diaphoretics. Volatile oils
are less energetic, for they often pass off with such ease as
not sensibly to increase the secretion of the skin.
Some acrid matters, as Guaiacum, Mezereon, and Senega,
appear to act specifically on the function of the skin. So also
do certain Narcotics, among which Opium is conspicuous as
the most certain Diaphoretic that we possess, though its other
operations prevent it from being applicable in all cases.
Antimony, Mercury, and Sulphur, are medicines which appear
to a greater or less degree to increase all the secretions
in the body. When given in the insoluble form, they are reduced
by the system to a soluble state. When Tartar Emetic
is given in small doses, its only apparent action is slightly to
increase the perspiration. It is probable that it then passes
out through the glands of the skin. When given in emetic
doses, it may produce sweating indirectly, as mentioned above.
Iodine, which also increases secretion generally, acts sometimes
as a Diaphoretic.
Many volatile oils have been detected by their odour in the
perspiration, as those of Garlic, Onion, Asafœtida, Musk,
and Copaiba. Mercury, Sulphur, and Iodine, have been detected
chemically in it. It has happened, when a course of
Mercury has followed the administration of Sulphur, that
parts of the skin have turned black, from the formation of
Sulphuret of Mercury. So it is proved of many of these
Diaphoretics, and thus rendered highly probable of the rest,
that they are true Eliminatives, being themselves excreted by
the glands which they excite to action.
When copious diaphoresis has been excited, care should be
taken that it be allowed to subside gradually, or the consequences
may be hurtful. It may be remarked that cleanliness
of the surface, by which the sudoriferous ducts are kept open
and healthy, is highly important to the proper function of
the skin.
Diaphoretics are useful in various disorders. In what is
called a cold, when the function of the skin has been suddenly
interfered with, and the vaporous transpiration is all thrown
upon the lungs, producing irritation or inflammation of the
respiratory mucous surface, Diaphoretics are generally required.
In Fevers, and some other disorders, as Gout and
Rheumatism, which are apt to improve or to pass off with an
increase of perspiration, and in which it often seems likely
that some morbid material may be eliminated by this channel,
the same medicines are constantly necessary. When another
secretion is unduly copious, an increase in the sweat may
cause it to diminish. Thus in some cases of diarrhœa, and
still more in diabetes, Diaphoretics are appropriate. In contrary
conditions, as when the formation of urine is unnaturally
small, on account of granular degeneration of the kidney, it
is again important to stimulate the secretion of the skin, that
it may, if possible, be able to replace the other. (Vide p. 280.)
Ord. VI. Diuretics.
These are medicines which tend to increase the secretion of
urine.
By means of the kidneys a large amount of aqueous material
is every day separated from the blood, and excreted.
This water is in the first instance absorbed by the surface of
the stomach and intestine. The causes which demand its
excretion are twofold. In the first place, it is necessary that
the blood should be kept down to its normal standard as
regards water, and that the surplus fluid which is daily added
to it should be removed. Secondly, this water is required in
the urine as a vehicle, to hold in solution there certain soluble
matters which are continually forming in the blood, or
being received into it, but which have to be excreted from it
by means of the kidneys. These matters comprehend a variety
of salts,—and a number of nitrogenous substances, of which
the best-known are urea and uric acid. These last are formed
in the blood by the gradual decomposition or change of the
animal tissues through which it flows. When retained in the
circulation, on account of a failure of the function of the kidneys,
they act as poisons.
The kidneys are the chief emunctories of water; and mineral
substances which are soluble in water tend for this reason to
pass out into the urine. Many of these, as the salts of Iron,
Silver, Lead, and Copper, are Astringents, and tend to diminish
rather than to increase the amount of urine. But the
urine is so necessary and so constant a secretion, that it is
very difficult to diminish it in quantity. Saline medicines act
as Diuretics under certain conditions. So also do acids and
alkalies, and many vegetable substances, which will be presently
spoken of.
The soluble substances which thus pass off in the urine, and
act as Diuretics, are many in number, but they are all uncertain
in action, for several reasons. The amount of the urine
depends very much on the quantity of water taken into the
stomach, or absorbed from the atmosphere through the skin;
so that when there is not a sufficient quantity of water in the
system, it is impossible for more urine to be formed. This
necessary absorption of water depends again upon the pressure
of the circulation; when this is too great, it cannot go on,
and the urine is diminished. A large increase in any other
of the secretions, as that of the bowels,—but particularly of the
skin, as in warm dry weather,—hinders diuresis. The secretion
of the urine is favoured by those conditions which repress
the perspiration; as by coldness of the surface, light clothing,
a cold and damp condition of the atmosphere, and the erect
posture. In the fourth place, the urine is diminished by
causes which impede the circulation, as by congestion of the
kidney or liver,—or of the whole venous system, on account
of obstruction in the heart,—conditions which produce dropsy.
Those medicines act as indirect Diuretics, which, by favouring
the removal of one of these hindering causes, tend to allow
the secretion of urine to go on as in health. The powerful
action of the heart in fevers and inflammations causes such a
pressure on the vessels as to retard absorption, and thus hinders
diuresis. A hard bounding pulse and hot skin favour
sweating more than diuresis, though they often diminish both
of these secretions. Both are assisted by a relaxed state of
the circulation, which favours the absorption of fluids. Thus
venesection, purging, Antimony, or any thing that diminishes
a febrile reaction, will help diuresis in such cases. In cases
of congestion on account of cardiac disease, Digitalis, which,
by powerfully weakening the force of the heart, both diminishes
congestion and favours absorption, is a most efficient
promoter of the natural function of the kidneys. When the
portal circulation is the seat of the obstruction, a mercurial,
such as blue pill, which especially acts on the liver, will be a
most desirable adjunct to the other remedies employed. Tobacco
and Lobelia, like Digitalis, promote diuresis by diminishing
the force of the heart.
True Diuretics.—Though all true Diuretics pass into the
urine, the converse of this, i.e. that all matters which pass
into the urine are Diuretic, is not always true. Thus the
astringent mineral salts pass frequently out of the system in
the urine, but seldom affect its amount in either way. And
for the reasons already enumerated, it is often impossible, even
by the most powerful medicines of this order, to increase the
urine beyond a certain amount.
Diuretics may be somewhat loosely arranged in four groups:—1.
Water, and soluble mineral substances, i.e. acids, alkalies,
and salines under certain conditions; 2. Acrid matters
of various kinds; 3. Alcoholic and ethereal liquids; 4. The
minerals which increase all secretions.
Diluents promote the secretions of the skin and kidneys.
A certain quantity of water must be given with every diuretic
dose, and the larger the quantity the greater will be the effect
produced. In the case of a Diaphoretic, this is all that is required.
But as Diuretics are generally given, as in dropsies,
for the purpose of eliminating fluid out of the system, this
object would be clearly defeated by the introduction of a large
quantity of water into the system. This, therefore, should be
avoided. The free acids, both mineral and vegetable, with
the exception of Sulphuric acid (vide p. 262,) pass into the
urine, and act as Diuretics. So also do the mineral alkalies.
But as these medicines have important agencies in the blood,
and tend further, by altering the reaction of the urine, to produce
in it deposits of different kinds (vide p. 151,) they can
seldom be safely employed for this purpose. Salines are more
appropriate. They should not be given in large doses, for
they will then act upon the bowels. The dose should be small,
and moderately diluted with water. To prevent it from acting
upon the skin, the conditions which favour diaphoresis should
be, if possible, avoided. The subject of the action of saline
medicines, and the effect of dilution upon this action, has been
already considered. (P. 74.)
The acrid Diuretics are perhaps the most powerful medicines
in the order. One of them, Cantharides, is an animal product.
Some contain or consist of volatile oils: as Juniper,
Turpentine, Cajeput, Copaiba, Horseradish. These volatile
oils may act upon the skin instead of the kidneys, under the
conditions which are mentioned above as favouring diaphoresis.
Others of this group contain peculiar vegetable principles; as
Broom, Chimaphila, Taraxacum, Colchicum, and Squill.
Alcohol, Ether, and Nitric ether, act powerfully both on
the kidneys and on the skin. Wine, which further contains
certain volatile oils, and sometimes a vegetable acid, acts on
the kidneys when drunk in any quantity. The diuretic effect
of these liquids is, as in the case of salines, greater when the
surface is cold, and less when it is warm and covered.
Mercury, Antimony, and Iodine, which increase more or
less all the animal secretions, act, among others, upon the
secretion of urine. Iodine particularly is said to be diuretic.
Mercury and Antimony are most efficacious as indirect
agents; the former by stimulating the function of the liver
when impaired, the other by diminishing the pressure on the
vessels in febrile cases.
A large number of Diuretics are themselves secreted by the
kidneys, and have been proved to pass out into the urine. A
great many have been detected in the urine by different
chemists, especially by M. Wöhler. The Carbonate, Nitrate,
and Chlorate of Potash, and the Iodide of Potassium, have
been found there. So also have the mineral acids—the
vegetable acids—Magnesia—Mercury,[46] in combination—and
Iodine, in the form of Hydriotic acid. Among vegetables,
the principles of Chimaphila and Uvæ Ursi—the oils of Turpentine
and Juniper, somewhat altered in nature—the oil and
resin of Copaiba—and the acrid principle of Cubebs, all pass
into it. Other substances, which are not diuretic, but astringent,
have been found in the urine; as Alum, Lead, and the
Morphia and Meconic acid of Opium.
When a powerful Diuretic is given in too large a dose, it
may cause a degree of action sufficient to produce congestion
of the kidney, and so defeat the object for which it was intended.
For congestion of a gland is invariably followed by a
diminution or stoppage of its secretion. So a large dose of
Turpentine or Cantharides may cause a dangerous attack of
strangury, or even a total suppression of the urine for a time.
(Vide p. 274.)
It can hardly be said that Diuretics are of very extensive
application in the treatment of disease, or that they are medicines
which can ever be much relied upon. For not only
are the remedies themselves uncertain in action, but it happens
also that the disorders in which they are most required
are of a peculiarly obstinate nature.
There are two chief actions for which Diuretics may be
required. They may be used: (1.) to eliminate solid materials
from the blood; (2.) to promote absorption, by diminishing
the amount of fluid in the blood. It is easier to
employ the first than to exert the second of these operations.
When there is habitually a deposit in the urine, of lithates,
or phosphates, or other solid matters, the simplest mode of
obtaining a solution of this deposit, and thus preventing dangerous
consequences, is to increase the amount of the fluid
part of the secretion. Water is the best medicine for this
purpose, and all Diuretics that are given with such an object
should be freely diluted with water. In Gout and Rheumatism,
remedies of this order may be of service by promoting
the excretion from the blood of the uric or lactic acid formed
there. They may also be used as Eliminatives in fevers and
other disorders. In the strangury which may sometimes follow
the application of a blister to the skin, copious draughts
of water are often prescribed with advantage, for they serve
to wash out of the blood the acrid matter which has been absorbed
from the surface.
It is for the second purpose, in cases of dropsy, produced
by congestion of the liver, kidneys, or general circulation,
that Diuretics are most urgently required, but are least efficacious.
This congestion or pressure on the veins diminishes
the amount of the secretion of urine, and by so doing
increases itself, and aggravates the effusion and disorder.
The same cause most effectually hinders the action of a
Diuretic. If only we could largely increase the secretion of
urine, the pressure on the venous system would be diminished,
and absorption of the effused fluids might take place.
In some cases of dropsy caused by renal congestion, the
attempt is so hopeless that it is better to resort to Diaphoretics.
In obstruction on account of heart disease, or congestion
of the liver, we may sometimes gain our point by
combining other Diuretics with Digitalis or Blue-pill, remedies
which tend to remove the causes by which the diuretic
action is hindered. (Vide p. 304.) Even then we can often
produce a much more copious and effectual drain of fluid from
the blood by an action on the bowels, as by a dose of Jalap or
Elaterium. When a Diuretic is required to eliminate fluid
from the system, the dose should not be much diluted with
water; this should only be done when we desire to eliminate
solids from the blood. It is often advisable to combine together
a number of different Diuretics, in the same prescription,
so that by their joint but various agencies the causes
which hinder their action may be overcome. The operation
of Diaphoretics is opposed to that of Diuretics, but it is not
always so with purgative medicines. The urine is often increased
by the action of a hydragogue Cathartic; and a combination
of Blue-pill and Squill supplies us with one of the
best of known Diuretics. It is applicable in cardiac dropsy
as well as in hepatic cases.
Thus is concluded a brief outline of the actions and uses
of the six orders of Eliminative medicines.
