Arsenic is by far the most important of metallic
poisons, whether we consider the deadliness of its
effects or the fatal frequency with which they are
made manifest. Arsenic exists as an impurity in
several metallic ores, notably in iron pyrites,
which being commonly employed as a material
for the manufacture of sulphuric acid, renders
arsenic one of the most frequent impurities of
commercial oil of vitriol. This should never be
forgotten in testing any substance for the poison.
To the common medicinal preparation of arsenic,
consisting of arsenious acid, or arsenites, and the so-called
chloride of arsenic, must be added the arseniates
of potash and soda; the sulphides of arsenic—as,
the red sulphide, or realgar, and the yellow sulphide,
or orpiment; the arsenite of copper, or Scheele’s
green, and others. They all produce similar symptoms,
and poisoning by either of them requires
nearly the same treatment.
According to Von Tschudi, some of the peasants
in parts of Styria and Hungary eat arsenic, taking
from two to five grains daily; the men doing so in
order that they may gain strength, and be able to
endure fatigue, the women that they may improve
their complexions. These statements are so contrary
to all that we know of the power of this
poison, that they have been regarded as unworthy
of credit. Evidence has, however, been brought
forward by Dr. Craig Maclagan, of Edinburgh,
which shows clearly that arsenic-eating is something
more than a mere fiction. This gentleman
gave, and saw a Styrian eat, a piece of arsenious
acid, weighing over four grains, and afterwards
determined the presence of arsenic in urine passed
in his presence by the said peasant. Advantage
was taken of these reports in the trial of Miss
Madeline Smith (Edinburgh, July, 1857), when the
court was asked to believe that arsenic found in
the possession of the prisoner was used by her as
a cosmetic.
Arsenite of Copper, in one form or another, either
as Scheele’s green, emerald green, Brunswick
green, &c., is unfortunately largely employed in
the manufacture of green paper-hangings, artificial
flowers, toys, and even some kinds of confectionery.
Too many cases of ill-health caused by this
practice have been recorded to permit any doubt
as to its deleterious effects. These may be manifested
by people living in rooms furnished with
such paper-hangings. The chief symptoms are,
sneezing, lachrymation, frontal headache, nausea,
and loss of appetite, with colicky pains, thirst, &c.
Among those employed in preparing the paper-hangings
more serious symptoms manifest themselves.
The irritation of the pigment gives rise to
circular patches of ulceration on the alæ of the
nose, in the folds of the arm, in the groin and
scrotum—in short, wherever dirt tends to lodge.
These prove very untractable, except the employment
be abandoned. In November, 1861, a young
woman died in London from the poisonous effects
of arsenite of copper used in dusting wax leaves.
The workmen who employ the pigment in its dry
state suffer, while those who use it in a moist condition
are probably unaffected by it. A simple
method for roughly detecting arsenite of copper in
these fabrics was published in the Chemical News
(vol. 1, p. 12). A small portion of the suspected
material is to be put into a test tube with strong
ammonia. If a blue tint be produced, a salt of
copper is shown to be present. Withdraw the object,
and drop a piece of nitrate of silver into the
ammonia; if arsenic be there, the nitrate of silver
will be covered with a yellow coating of arseniate
of silver, which will disappear on stirring. On
igniting arsenical paper and allowing it to smoulder,
the odor of garlic may be detected in the
fumes given off. Another mode in which the
noxious effects of arsenic are produced is by the
use of bright green tarlatans as ball dresses.
One could hardly conceive a more deadly amusement
than dancing in an arsenicated dress, sweeping
against an arsenicated wall-paper. When
both are lightly adherent the arsenic is scattered
in showers about the room.
Arsenious Acid (White Oxide of Arsenic, White
Arsenic, Arsenic).—This is the preparation of arsenic
most frequently used as a poison; the facility
with which it used to be procured, its cheapness
(twopence an ounce), and the ease with which it
may be administered, all tended to recommend it
to the murderer or suicide. According to a parliamentary
report, the number of fatal cases of
poisoning in England in the years 1837, 1838,
amounted to 543, of which no less than 186 were
caused by arsenic, 185 arising from the use of the
arsenious acid, and 1 from orpiment or yellow arsenic.
Since the Act of 1851 (14 Vict. cap. xiii.) the
deaths from this agent have greatly decreased.
This statute chiefly enacts that arsenic is not to be
sold without the seller entering the transaction in
a proper book, without a witness, nor without its
being mixed with soot or indigo, unless such admixture
would render it unfit for the purchaser’s
business.
Arsenious acid is found in commerce in the form
of a white powder or in small opaque cakes. It is
very feebly acid, tasteless, or slightly sweet in small
doses, though not very soluble, an ounce of cold
water dissolving about one grain. The quantity so
held in solution may, however, be increased by
dissolving the arsenic in boiling water and allowing
it to cool. The shortest period within which
it was believed arsenic would cause death was two
hours; but Dr. Taylor gives a case where death
with tetanic symptoms followed the fatal dose in
twenty minutes. The smallest quantity known to
have proved fatal is two grains. Two grains and
a half killed a girl nineteen years of age in thirty-six
hours. Half a grain will produce alarming
symptoms; and yet recovery has ensued after doses
of half an ounce or an ounce.
Symptoms.—These commence within half an
hour or an hour of swallowing the poison. There
is faintness, nausea, incessant vomiting, and a
burning pain in the epigastrium, increased on
pressure, and gradually extending over the whole
abdomen, followed by headache, diarrhœa, a sense
of constriction and heat in the fauces and throat,
great thirst, and catching, painful respiration. The
heart’s action becomes depressed, the pulse is quick
and feeble; there is great restlessness and anxiety;
cold, clammy skin, and perhaps coma are present;
and death usually occurs within twenty-four
hours.
These symptoms are liable to great variety, the
pain and vomiting being occasionally absent, and
the patient being affected as if by a narcotic poison.
In some instances there is troublesome tenesmus,
with heat and excoriation about the anus. Convulsive
movements in the extremities often occur,
with cramp in the legs, especially if the diarrhœa
is severe. Death sometimes takes place calmly
from collapse, sometimes it follows on convulsions.
The vomited matters may be red or brown from
admixture with blood or bile; or they may be blue
or black, if the arsenic has been colored with
indigo or soot. Although the vomiting, pain, &c.,
are generally continuous, yet sometimes all the
symptoms remit, and the patient rallies for a time,
only to sink more rapidly.
The symptoms of chronic poisoning by arsenic
are loss of appetite, a silvery coating to the tongue,
thirst, nausea, colicky pains, diarrhœa, frontal
headache, langor, sleeplessness, cutaneous eruptions,
soreness of the edges of the eyelids, emaciation,
anæmia, convulsions, and death. In some
cases, when small doses have been administered
for many days in succession, with the intent to
destroy life, the symptoms have been masked by
other substances. The most marked results of
this practice have been sickness and vomiting, pain
in the bowels, nervous irritability, and emaciation.
The practitioner must be careful not to mistake
these symptoms for those due to simple gastritis
or enteritis.
Arsenic is not a poison that accumulates in the
system, but is slowly eliminated from it especially
by the kidneys, but partly also by the bile.
The local application of arsenic to the mucous
membranes, to wounds, or to surfaces deprived of
their cuticle, produces constitutional effects similar
to those just described. The only difference is
that the symptoms show themselves more slowly.
Not a few lives have been sacrificed from the
application by ignorant quacks of a mixture of
arsenious acid, realgar, and oxide of iron to
ulcerating cancers.
Cases of compound poisoning have been met
with. When arsenic is taken mixed with opium,
the symptoms produced by the former are masked.
Post-mortem Appearances.—Arsenic appears to
exercise a specific influence over the alimentary
canal, and more especially over the stomach; for
in whatever manner it may have been introduced
into the system, it is to this organ that we must
look for its effects. These effects consist in the
signs of acute inflammation commencing in this
viscus, and often extending along the duodenum,
small intestines, and colon. In acute cases the
stomach is the viscus most affected; but in chronic
cases the whole alimentary canal is found inflamed
and ulcerated, particularly the duodenum and
rectum. When death has occurred within five
hours of taking the poison, the stomach has been
found intensely inflamed in an adult; while the
same result was witnessed in a child who died at
the end of two hours. The stomach often contains
a dark grumous fluid, occasionally tinged with
blood. On removing the contents the mucous
membrane is seen red and inflamed, the inflammation
being most intense around certain spots.
On examining these spots, particles of arsenic will
probably be found adhering to the walls of the
stomach and surrounded by a zone of inflammatory
redness. Sometimes also blood is effused
into the visceral walls, giving rise to an appearance
resembling gangrene. Ulceration of any of
the coats of the stomach is rare, and perforation is
still more so.
In a few exceptional cases there has been no
appearance of inflammation in the stomach or
bowels.
Putrefaction of the body is said to be remarkably
retarded after death from arsenic.
Treatment.—The first object must be to expel
the poison from the stomach, for which purpose
the stomach-pump may be advantageously employed,
or emetics of sulphate of zinc, mustard, or
ipecacuan administered, unless vomiting is already
present. The sickness must be promoted by the
free use of albuminous or mucilaginous diluents.
Raw eggs beaten up in milk are particularly useful,
as is likewise a mixture of albumen, milk,
and limewater. Taylor advises equal parts of oil
and limewater, for the oil invests the poison, and
the lime renders it less soluble. A large dose of
castor oil (℥j to ℥ij) may be given, to carry off any
of the poison which may have passed into the intestines,
as soon as sickness has subsided. Animal
charcoal, calcined magnesia, &c., when taken in
large quantities, may be of service by enveloping
the arsenic, and preventing its contact with the
mucous membrane of the stomach; but oil or
milk will act more efficiently in this manner. The
hydrated peroxide of iron[B] should be administered
moist, and in large doses, after the stomach-pump
has been used; or indeed, mixed with water, it
may be first introduced and then expelled, thus
washing out the stomach by means of the stomach-pump.
This is the most efficient antidote known.
The subsequent treatment must be conducted on
general principles, according to the severity of the
symptoms; but the great depression of the nervous
and vascular systems must not be overlooked
in combating any inflammatory action. Henbane
or opium, in many instances combined with stimulants,
ice internally, and hot fomentations externally,
will frequently be found of great service.
Tests.—In its solid state arsenious acid may be
known by the following properties. Heated on
platinum foil or on the point of a penknife, it produces
a white smoke and is entirely volatilized.
If some of the powder be heated in a small test tube,
it will be sublimed, and small octahedral crystals,
visible to the naked eye or by a lens, obtained.
If arsenious acid be mixed with freshly-burnt powdered
charcoal, and heated in a small test tube, a
ring of shining metallic arsenic of a grey color
will be found on the cool portion of the tube, and
an odor of garlic is perceptible. If this deposit
be driven about from place to place it will gradually
become oxidized, and octahedral crystals
of arsenious acid formed. Further, if the tube be
divided and the part containing the arsenious acid
be washed out with distilled water, the liquid tests
may be applied to the solution. This is called
the Reduction test. It is very delicate, detecting
according to Christison, the 300th part of a grain.
In solution, this substance may be detected by
what are called the liquid tests. A solution of
arsenic in water is colorless, almost tasteless, and
has a very slightly acid reaction. If a few drops
be evaporated on a glass slide and examined by
the microscope, numerous minute and mostly imperfect
octahedral crystals, or an amorphous
deposit, will be seen, presenting triangular surfaces
by reflected light.
1. The ammonio-nitrate of silver (prepared by
adding a few drops of liquor ammoniæ to a solution
of nitrate of silver, till the brown oxide of silver at
first precipitated is nearly redissolved) throws
down with arsenious acid a rich yellow deposit of
arsenite of silver.
2. The ammonio-sulphate of copper (formed by
adding liquor ammoniæ to a solution of sulphate
of copper till the bluish-white oxide of copper is
almost redissolved) produces a pale green precipitate,
arsenite of copper, or Scheele’s green.
Care must be taken not to add too much of the test
in the first instance, otherwise its blue may overpower
the green of the precipitate.
3. Sulphuretted hydrogen water precipitates a
yellow deposit of sulphide of arsenic. It is better,
however, to use pure and well-washed sulphuretted
hydrogen generated in the usual manner.
Care must be taken that the liquid is not alkaline,
or no precipitate will be produced, even though
arsenic be present. For this reason yellow sulphide
of ammonium will not precipitate arsenic until
acidulated with pure hydrochloric or some such
acid. The precipitate should be collected, carefully
washed, and dried. It should then be mixed
with black flux or dry ferrocyanide of potassium
and reduced, as already described.
These tests are so delicate, especially the first,
that they will detect the 8000th part of a grain of
arsenic in solution; they should be employed
successively. There are several other processes
which require to be noticed, namely, Marsh’s process,
the process known as Reinsch’s process,
Fresenius’s process, and the Destillation process.
Marsh’s Test or Process.—This process is founded
on the decomposition of arsenious acid by nascent
hydrogen, and the formation of arsenuretted hydrogen
gas, which possesses the following properties:
It burns with a bluish-white flame, and white
smoke (arsenious acid), possessing a slight garlic
odor. If a piece of glass or porcelain be held in
the flame a blackish metallic stain will be deposited
upon it, consisting of metallic arsenic. This
stain might be confounded with one produced by
antimony under similar circumstances. But the
antimonuretted hydrogen gas does not burn with
the odor of the arsenuretted hydrogen; while
the antimonial stain is sooty, and has not a metallic
lustre. The arsenical stain is further readily
dissolved by a solution of chloride of lime (bleaching
powder), whilst the antimonial stain is not
affected. To the stain may be added a few drops
of strong nitric acid; it will dissolve the arsenic;
if this be allowed to evaporate, and the acid be
neutralized, a few drops of nitrate of silver solution
will give a brick-red precipitate of arseniate of
silver.
Marsh’s test is thus accomplished: a flask furnished
with a cork through which pass a funnel
and a long bent tube drawn to a point, is prepared
so that the funnel reaches almost to its bottom.
Several pieces of pure zinc are introduced, and
then some sulphuric acid is poured through the
funnel. In this way hydrogen gas is produced
and escapes by the bent tube. When all the air
has been expelled the gas should be ignited as it
escapes, and a piece of cool porcelain held over
the flame. If there be no deposit it is plain that
neither the zinc nor the sulphuric acid, contains
arsenic. A portion of the suspected fluid is next
introduced into the flask by the funnel, and the
issuing gas again tested. Should a stain giving
the characters alluded to above be produced, the
fluid contains arsenic in some form or other.
Reinsch’s Process.—The suspected liquid is boiled
with from one-sixth to one-eighth of its bulk of
pure hydrochloric acid, and a bright slip of copper
introduced. If arsenic be present the copper
will be coated with it in the form of an iron-grey
deposit. Next after removing the copper, washing
it with distilled water, and drying it between
folds of blotting paper, cut it into slips, and introduce
it into a reduction-tube and apply heat;
arsenious acid will be sublimed and deposited on
the sides of the tube, in the form of minute octahedral
crystals. These may be dissolved in water
and tested in the usual way. Before resorting to
this test, the acid must be examined to make sure
of its purity. This is easily effected by boiling
the copper with a mixture of the hydrochloric acid
and distilled water before adding the suspected
liquid. In conducting the analysis in the case of
Smethurst (Cent. Crim. Court, Aug. 1859) Taylor
and Odling found that all the varieties of copper
in common use for Reinsch’s process contained
arsenic. A copper of ascertained purity must
therefore be used.
Arsenic in Organic Matters.—The following process,
which has been introduced by Dr. Taylor, is
a very convenient one. The suspected matters
are to be thoroughly dried in a water-bath or
otherwise, taking care not to use too great a heat.
They are then to be introduced into a flask fitted
with a long bent tube; to the dried material is to
be added a quantity of strong hydrochloric acid,
proved free from arsenic, sufficient to drench it,
and the whole allowed to digest for some hours.
At the end of that time heat is to be applied to the
flask by means of a sand-bath, and a receiver fitted
to the bent tube. The receiver should contain
a little water, and both it and the bent tube
should be kept cool. As distillation goes on the
arsenic passes over in the form of chloride of arsenic,
and is collected in the receiver beyond. A
second portion of hydrochloric acid may be used
to remove any last traces of arsenic in the organic
material. The arsenic may be recovered from the
chloride by boiling with pure polished copper, as
in Reinsch’s process.
The process of Fresenius and Von Babo given at
page 31 is especially adapted for the recovery of
arsenic from organic admixture.
Several cases of poisoning by arsenuretted hydrogen
are on record, some proving fatal.