excites in Man._
The effects of hydrocyanic acid on the animal system have been examined
by several physiologists. The best experiments with the concentrated
acid are those of M. Magendie; who says that, if a single drop be put
into the throat of a dog, the animal makes two or three deep hurried
respirations, and instantly drops down dead; that it causes death almost
as instantaneously when dropped under the eyelid; and that when it is
injected into the jugular vein, the animal drops down dead at the very
instant, as if struck with a cannon ball or with lightning.[1855]
On repeating these experiments in order to determine less figuratively
the shortest period which elapses before the poison begins to operate,
as well as the shortest time in which it proves fatal,—two points it
will presently be found important to know,—I remarked that a single
drop, weighing scarcely a third of a grain, dropped into the mouth of a
rabbit, killed it in eighty-three seconds, and began to act in
sixty-three seconds,—that three drops weighing four-fifths of a grain,
in like manner killed a strong cat in thirty seconds, and began to act
in ten,—that another was affected by the same dose in five and died in
forty seconds,—that four drops weighing a grain and a fifth did not
affect a rabbit for twenty seconds, but killed it in ten seconds
more,—and that twenty-five grains, corresponding with an ounce and a
half of medicinal acid, began to act on a rabbit as soon as it was
poured into its mouth, and killed it outright in ten seconds at
farthest. Three drops injected into the eye acted on a cat in twenty
seconds, and killed it in twenty more; and the same quantity dropped on
a fresh wound in the loins acted in forty-five and proved fatal in 105
seconds. Dr. A. T. Thomson says he has seen the concentrated acid kill a
strong dog in two seconds.[1856] Mr. Blake on the other hand alleges
that all the accounts which represent the action of the poison to begin
in less than ten seconds are exaggerated, because he could never find it
to act more quickly, even when thirty minims of concentrated acid were
injected at once into the femoral vein.[1857] But it is impossible that
any negative results can outweigh positive observations, especially when
made, as mine were, expressly with the view of ascertaining the shortest
interval. In the slower cases enumerated above there were regular fits
of violent tetanus; but in the very rapid cases the animals perished
just as the fit was ushered in with retraction of the head. In rabbits
opisthotonos, in cats emprosthotonos, was the chief tetanic symptom.—The
practical application of these experiments will appear presently.
Of all the forms in which the pure acid can be administered, that of
vapour appears the most instantaneous in operation. M. Robert found,
that when a bird, a rabbit, a cat, and two dogs were made to breathe air
saturated with its vapour, the first died in one second, the second also
in a single second, the cat in two, one dog in five, and the other dog
in ten seconds.[1858]
The effects of the diluted acid are the same when the dose is large, but
somewhat different when inferior doses are given. These effects have
been observed by many physiologists; but the most accurate and extensive
experiments are those of Emmert published in 1805,[1859] those of
Coullon in 1819,[1860] and those of Krimer in 1827.[1861] They found
that when an animal is poisoned with a dose not quite sufficient to
cause death, it is seized in one or two minutes with giddiness, weakness
and salivation, then with tetanic convulsions, and at last with
gradually increasing insensibility; that after lying in this state for
some time, the insensibility goes off rapidly and is succeeded by a few
attacks of convulsions and transient giddiness; and that the whole
duration of such cases of poisoning sometimes does not exceed half an
hour, but may extend to a whole day or more.—When the dose is somewhat
larger the animal perishes either in tetanic convulsions or comatose;
and death for the most part takes place between the second and fifteenth
minute. I have seen the diluted acid, however, prove fatal with a
rapidity scarcely surpassed by the pure poison. Thus in an experiment
with Vauquelin’s acid, made on a strong cat at the same time with the
second and third of the experiments with the pure acid detailed above, I
found that thirty-two grains, which contain one of real acid, began to
act in fifteen seconds, and proved fatal in twenty-five more. According
to Schubarth’s experiments death may be sometimes delayed for thirty-two
minutes;[1862] but if the animal survives that interval, it recovers. He
farther states, that during the course of the symptoms the breath
exhales an odour of hydrocyanic acid.[1863] Coullon once saw a dog die
after nineteen hours of suffering; but cases of this duration are
exceedingly rare.[1864] When the dose is very large Mr. Macaulay, as
will afterwards be mentioned (p. 590), has found death take place in a
few seconds, exactly as when the pure acid is given.
The body presents few morbid appearances of note. The brain is generally
natural. Yet occasionally its vessels are turgid; and Schubarth once
found even an extravasation of blood between its external membranes in
the horse.[1865] The heart and great vessels are distended with black
blood, which is commonly fluid, but occasionally coagulated as usual.
The lungs, according to Schubarth, are sometimes pale, but much more
generally injected and gorged with blood.[1866] The pure acid, according
to Magendie, exhausts the irritability of the heart and voluntary
muscles so completely, that they are insensible even to the stimulus of
galvanism.[1867] The diluted acid has not always this effect. In the
experiments of Coullon the heart and intestines contracted, and the
voluntary muscles continued contractile, after death as usual.[1868] So
too Mr. Blake remarked both by inspection of the body after death, and
by means of the hæmadynamometer during life, that, when the poison is
introduced directly into a vein, so as to prove fatal in forty-five
seconds, the contractions of the heart, though irregular, are not
materially impaired in energy.[1869] On the other hand Schubarth states
that the heart is never contractile, although the intestines and
voluntary muscles retain their contractility.[1870] The reason of these
discrepant statements is that, as I have had occasion to observe, a
considerable difference really prevails in experiments conducted under
circumstances apparently the same. In eight experiments on cats and
rabbits with the pure acid the heart contracted spontaneously, as well
as under stimuli, for some time after death, except in the instance of
the rabbit killed with twenty-five grains, and one of the cats killed by
three drops applied to the tongue. In the last two the pulsations of the
heart ceased with the short fit of tetanus which preceded death; and in
the rabbit, whose chest was laid open instantly after death, the heart
was gorged and its irritability utterly extinct. The later researches of
Dr. Lonsdale likewise show great varieties in the condition of the
heart; and he has been led to conclude that the diluted acid does not
perceptibly influence the heart, while the pure acid enfeebles it, if
introduced into the stomach, but arrests it, if injected into the
windpipe.[1871]
The experiments of Emmert, Coullon, and Krimer show that the diluted
acid acts most energetically through the serous membranes, and next upon
the stomach; that it also acts with energy on the cellular tissue; that
it has no effect when applied to the trunks or cut extremities of
nerves, or to a fissure made in the brain or spinal marrow; that its
action is prevented when the vessels of any part are tied before the
part is touched with the poison; that its action is not prevented by
previously dividing the nerves; and that it may sometimes be discovered
in the blood after death by chemical analysis,[1872] and frequently by
the smell when analysis cannot succeed in separating it.[1873] These
results favour the supposition that hydrocyanic acid acts through the
medium of the blood-vessels. But the extreme rapidity of its operation
in large doses is usually considered incompatible with an action through
the blood, or any other channel except direct conveyance along the
nerves. The tremendous rapidity of action indicated by the experiments
of Magendie, or of Mr. Macaulay (p. 543), of M. Robert, as well as in
some of those performed by myself,—certainly appears rather inconsistent
with the notion, that the acid must enter the blood-vessels before
producing its effects.
This acid acts on the brain and also on the spine independently of its
action on the brain. Its action on both is clearly indicated by the
combination of coma with tetanus. The independent action on the spine is
well shown by the following experiment of Wedemeyer. In a dog the spinal
cord was divided at the top of the loins, so that no movement took place
when the hind-legs were pricked: hydrocyanic acid being then introduced
into a wound in the left hind-leg, symptoms of poisoning commenced in
one minute, and the hind-legs were affected with convulsions as well as
the fore-legs.[1874]
Hydrocyanic acid affects all animals indiscriminately. From the highest
to the lowest in the scale of creation all are killed by it; and all
perish nearly in the same manner. Such is the result of a very extensive
series of experiments by Coullon.
It is scarcely necessary to observe that hydrocyanic acid acts
energetically as a poison, through whatever channel it is introduced
into the body. Whether it be swallowed, or injected into the rectum, or
dropped into the eye, or applied to a fresh wound, or inhaled in the
form of vapour, its action is exerted with tremendous energy. Perhaps it
may even act through the sound skin. It has not, hitherto, indeed, been
found to affect animals in this way, evidently because their skin is too
thick and impermeable. But M. Robiquet informed me that once, while he
was making some experiments on the tension of its vapour, his fingers,
after being some time exposed to it, became affected with numbness,
which lasted several days; I have repeatedly remarked the same effect
when handling tubes which contained the concentrated acid; and Emmert
found that the essential oil of bitter almond, applied to the uninjured
skin of the back of a rabbit, produced the usual symptoms and death: and
that the peculiar odour of the poison was quite distinct after death in
the deep-seated muscles of the back.[1875]
This substance is poisonous in all its chemical combinations. Coullon
remarked that two drops of the hydrocyanate of ammonia killed a sparrow
in two minutes.[1876] Robiquet and Magendie found that a hundredth part
of a grain of the cyanide of potassium killed a linnet in thirty
seconds, and five grains a large pointer in fifteen minutes;[1877]
Orfila has related an instance of death in the human subject within an
hour after the administration of six grains of cyanide of potassium in
an injection;[1878] and in a recent experimental investigation the same
author found that this salt produces all the effects of hydrocyanic
acid.[1879] Schubarth killed a dog in twenty minutes with twenty drops
of the diluted acid neutralized by ammonia,[1880] and another in three
hours with twenty-five drops neutralized by potass. These facts are a
sufficient answer to a statement made by Mr. Murray of London, to the
effect, that a considerable dose of the acid may be given without injury
to a rabbit,[1881] if previously rendered alkaline by ammonia. But,
nevertheless, as will be seen under the head of the treatment, ammonia,
as Mr. Murray stated, is a good antidote when administered after the
poison as a stimulant.
The _ferro-cyanates_, or prussiates, do not possess deleterious
properties. These salts were at one time considered compounds of
hydrocyanic acid with a double oxidized base, oxide of iron being one.
Thus the prussiate of potass was considered a compound of hydrocyanic
acid with potass and oxide of iron. But since the investigations of Mr.
Porrett, it has been admitted that there is only one base, potash; and
that it is in union with a hydracid, called ferro-cyanic acid, the
radicle of which is a ternary body composed of carbon, azote, and iron.
The physiological effects of this substance, which have been examined by
many experimentalists, are favourable to Porrett’s opinion; for although
some have found it poisonous, all agree in assigning it very feeble
properties, and some have not been able to discover in it any
deleterious quality at all. Coullon observes that Gazan killed a dog
with two drachms, and Callies another with three drachms of the salt met
with in commerce.[1882] Schubarth found that half an ounce had not any
material effect on dogs, even when vomiting did not occur for half an
hour;[1883] and Callies, who found the salt of commerce somewhat
poisonous, also remarked, that when it was carefully prepared, several
ounces might be given without harm.[1884] D’Arcet once swallowed half a
pound of a solution without any injury.[1885] Similar results were
obtained previously with smaller doses by Wollaston, Marcet,[1886] and
Emmert,[1887] as well as afterwards by Dr. Macneven,[1888] and
Schubarth,[1889] who found that a drachm or even two drachms might be
taken with impunity by man and the lower animals.
The _sulpho-cyanic acid_, another substance analogous in chemical nature
to the ferro-cyanic, was once supposed like it to be a poison of great
activity, but this is doubtful. Professor Mayer of Bonn ascertained that
a drachm and a half of a moderately strong solution of the acid
sometimes killed a rabbit in ninety seconds when injected into the
windpipe, and that the same quantity of a solution of sulpho-cyanate of
potassa might occasion death in the course of four hours; but that some
rabbits took half an ounce of the former and three drachms of the latter
without material harm, both when administered through the windpipe, when
injected into the rectum, and when introduced into the stomach by a
gullet-tube. In the fatal cases death took place under symptoms of
oppressed breathing, rarely attended with convulsions; and extensive
traces of irritation were found in the alimentary canal.[1890] Dr.
Westrumb of Hameln, however, seems to have found it more active in the
form of sulpho-cyanate of potassa. Two scruples in an ounce of water
produced in a dog spasmodic breathing, convulsions, efforts to vomit,
and death in seven minutes; and forty grains killed another in less than
two hours. In the latter animal he detected the poison by the sulphate
of iron in the blood, lungs, liver, spleen and kidneys.[1891] Some
experiments by Soemering would even make it out to be a poison of very
great energy; for half a drachm of concentrated sulpho-cyanic acid given
to a dog occasioned immediate death; and the same quantity of
sulpho-cyanate of potassa killed another in one minute.[1892]
_Cyanic and cyanous acids_ are not poisonous, according to the
experiments of Hünefield;[1893] but _cyanogen_ is a powerful poison, as
will be mentioned under the head of the Narcotic Gases.
The symptoms of hydrocyanic acid observed in man are very similar to
those witnessed in animals.
Coullon has given a good account of the effects of small doses as
ascertained by experiment on himself. When he took from 20 to 86 drops
of a diluted acid, he was attacked for a few minutes with nausea,
salivation, hurried pulse, weight and pain in the head, succeeded by a
feeling of anxiety, which lasted about six hours.[1894] Such symptoms
are apt to be induced by too large medicinal doses. Another remarkable
symptom which has been sometimes observed during its medicinal use is
salivation with ulceration of the mouth. Dr. Macleod thrice had occasion
to remark this in patients who had been using the drug for about a
fortnight, and twice in one individual; and Dr. Granville says he had
also twice witnessed the same effect.[1895]
As to the effects of fatal doses, it is probable that in man, as in
animals, two varieties exist. When the dose is very large, death will in
general take place suddenly, without convulsions. But for obvious
reasons the symptoms in such cases have not been hitherto witnessed.
The most complete account of the symptoms from fatal doses when
convulsions occur, is given in a case reported by Hufeland of a man,
who, when apprehended for theft, swallowed an ounce of alcoholized acid,
containing about forty grains of the pure acid. He was observed
immediately to stagger a few steps, and then to sink down without a
groan, apparently lifeless. A physician, who instantly saw him, found
the pulse gone and the breathing for some time imperceptible. After a
short interval he made so forcible an expiration that the ribs seemed
drawn almost to the spine. The legs and arms then became cold, the eyes
prominent, glistening, and quite insensible; and after one or two more
convulsive expirations he died, five minutes after swallowing the
poison.[1896]
In Horn’s Journal is recorded another case which also proved fatal in
five minutes, with precisely the same symptoms.[1897] A short notice of
what appears to have been a similar case is given in the Annales de
Chimie. The person was a chemist’s servant, who swallowed a large
quantity of the alcoholic solution by mistake for a liqueur, the poison
having been accidentally left on the table by her master, who had been
showing it as a curiosity to some friends. No account is given of the
symptoms, farther than that she died apoplectic in two minutes.[1898] To
these cases may be also added a short notice of the French physician’s
case mentioned at the commencement of this chapter. It will convey a
good idea of the operation of the poison when not quite sufficient to
kill. Very soon after swallowing a tea-spoonful of the diluted acid he
felt confusion in the head, and soon fell down insensible, with
difficult breathing, a small pulse, a bloated countenance, dilated
insensible pupils, and locked jaw. Afterwards he had several fits of
tetanus, one of them extremely violent. In two hours and a half he began
to recover his intellects and rapidly became sensible; but for some days
he suffered much from ulceration of the mouth and violent pulmonary
catarrh, which had evidently been excited by the ammonia given for the
purpose of rousing him. This gentleman had eructations with the odour of
the acid three or four hours after he took it; and during the earlier
symptoms the same odour was exhaled by his breath.[1899] The hydrocyanic
odour of the breath is of course an important distinguishing character,
which would appear, from the observations of Dr. Lonsdale on
animals,[1900] to occur more frequently than might be supposed from the
silence observed on the subject by the reporters of cases.
Hydrocyanic acid is not considered a cumulative poison,—that is, the
continued use of frequent small doses is not believed to possess the
power recognised in iodine, mercury, and foxglove, of gradually and
silently accumulating in the body, and then suddenly breaking out with
dangerous or fatal violence. The frequent experience of practitioners in
this and other countries seems to prove that hydrocyanic acid possesses
no such property. It is right at the same time to mention, that a case
published by Dr. Baumgärtner of Freyburg has been thought by some[1901]
to establish the reverse. A man had taken for two months, on account of
chronic catarrh, ten drops of Ittner’s acid daily in doses of one grain,
without experiencing the slightest toxicological effect. At length he
was found one morning in bed apparently labouring under the poisonous
operation of the acid. He had headache, blindness, dilated insensible
pupil, feeble irregular pulse, occasional suspension of the breathing,
and rapidly increasing insensibility. The cold affusion and ammonia were
immediately resorted to, and at first with advantage. But in no long
time spasms commenced in the toes, and gradually affected the rest of
the body, till at length violent fits of general tetanus were formed,
lasting for six or ten minutes, and alternating in the intervals with
coma. Venesection was next resorted to; after which the spasms were
confined to the jaw and eyes. Delirium succeeded, but was removed by a
repetition of the blood-letting. At four in the afternoon he was
tolerably sensible; during the night delirium returned; at ten next
morning he recovered his sight; and on the subsequent morning he had no
complaint but headache and pain in the eyes.[1902] This case differs so
much from every other in the collateral circumstances, as well as in
duration, that, although the symptoms themselves correspond with those
of poisoning with hydrocyanic acid, we may justly suspect either some
other cause, or the accidental administration of too large a dose. It
ought, however, to turn the attention of practitioners to the
possibility of this poison acting by the accumulation of the effects of
small doses frequently repeated for a great length of time.
The period within which hydrocyanic acid usually proves fatal is fixed
with considerable accuracy, not only by the cases observed in the human
subject, but likewise by the experiments of many physiologists, and more
especially those of Schubarth (p. 583). It is probable that very large
doses occasion death in a few seconds; and at all events a few minutes
will suffice to extinguish life when the dose is considerable; but if
the individual survive forty minutes, he will generally recover. In the
course of a dreadful accident which happened a few years ago in one of
the Parisian hospitals, when seven epileptic patients were killed at one
time by too large doses of the medicinal acid, it was found that several
did not die for forty-five minutes.[1903] But the researches of
Schubarth would certainly justify the expectation that recovery will
take place under active treatment when the patient survives so
long.—These facts may be highly important in the practice of medical
jurisprudence.
The period within which it begins to operate ought also to be accurately
ascertained for the same reason. Indeed in a very interesting trial,
which took place a few years ago in this country, the fate of the
prisoner depended in a great measure on the question, within how short a
time the effects of this poison must show themselves?[1904] The nature
of the case was as follows: An apothecary’s maid-servant at Leicester
who was pregnant by her master’s apprentice, was found one morning dead
in bed; and she had obviously been poisoned with hydrocyanic acid.
Circumstances led to the suspicion that the apprentice was accessary to
the administration of the poison. On the other hand, it was distinctly
proved that the deceased had made arrangements for a miscarriage by
artificial means on the night of her death; and it was therefore
represented, on the part of the prisoner, that she had taken the poison
of her own accord. But the body was found stretched out in bed in a
composed posture, with the arms crossed over the trunk, and the
bed-clothes pulled smoothly up to the chin; and at her right side lay a
small narrow-necked phial, from which about five drachms of the
medicinal prussic acid had been taken, and which was corked and wrapped
in paper. There naturally arose a question, whether the deceased, after
drinking the poison out of such a vessel, could, before becoming
insensible, have time to cork up the phial, wrap it up, and adjust the
bed-clothes?[1905] To settle this point, experiments were made at the
request of the judge, by Mr. Macaulay, Mr. Paget, and several other
medical men of Leicester; and on the trial they, with the exception of
Mr. Paget, gave it as their opinion, founded on the experiments, that
the supposed acts of volition, although within the bounds of
possibility, were in the highest degree improbable. The chief
experiments were three in number, from which it appeared that one dog
was killed with four drachms in eight seconds, another with four drachms
in seven seconds, and another with four drachms and a half in three
seconds; but in other experiments the interval was greater.—For these
particulars I am indebted to Mr. Macaulay.
In the first edition of this work I expressed my concurrence with the
majority of the witnesses. But some facts, which came subsequently under
my notice, led me to think that this concurrence was given rather too
unreservedly. I still adhere so far to my original views as to think it
improbable that, if the deceased, after swallowing the poison, had time
to cork the phial, wrap it in paper, pull up the bed-clothes, and place
the bottle at her side, the progress of the symptoms could have been so
rapid and the convulsions so slight, as to occasion no disorder in the
appearance of the body and the bed-clothes,—and I still likewise think,
that after swallowing so large a dose it was improbable she could have
performed all the successive acts of volition mentioned above—with
ordinary deliberation. But I am informed on good authority, that some
gentlemen interested in the case found by actual trial, that all the
acts alluded to might be accomplished, if gone about with promptitude,
within the short period, which, in some of their experiments, the
witnesses found to elapse, before the action of the poison commenced.
And such being the fact, we ought not perhaps to attach too great
importance to the other argument I have employed,—the probability of
disorder in the body and bed-clothes from the convulsions; for if the
poisoning commenced very soon, the convulsions might have been slight.
The results of my own experiments related in p. 582, although on the
whole confirmatory of those of Mr. Macaulay and his colleagues, are
nevertheless sufficient to prove that large doses occasionally do not
begin to operate with such rapidity as was observed in their
experiments; for in one instance four drops of concentrated acid,
equivalent to two scruples of medicinal acid, did not begin to act on a
rabbit for twenty seconds; and certainly, for so small an animal, two
scruples are as large a dose as five drachms for a grown-up girl.
The two following cases will throw some farther light on the time within
which this poison begins to act on man when taken in large quantity. The
first case shows, that even when an enormous dose is taken, a few simple
voluntary acts may be executed before the symptoms begin. In this
instance which is related by Dr. Gierl of Lindau, the dose was no less
than four ounces of the acid of the Bavarian Pharmacopœia, which
contains four per cent. of pure acid, and is equivalent to five ounces
at least of that commonly used in Britain and France. The subject, an
apothecary’s assistant, was found dead in bed, with an empty two-ounce
phial on each side of the bed,—the mattrass, which is used in Germany
instead of blankets, pulled up as high as the breast,—the right arm
extended straight down beneath the mattrass,—and the left arm bent on
the elbow.[1906] The second case proves that, although one or two acts
of volition may be accomplished, the interval is so very brief that
these acts can only be of the simplest kind. An apothecary’s
apprentice-lad was sent from the shop to the cellar for some carbonate
of potass; but he had not been a few minutes away, when his companions
heard him cry in a voice of great alarm, “Hartshorn! Hartshorn!” On
instantly rushing down stairs, they found him reclining on the lower
steps and grasping the rail; and he had scarcely time to mutter “Prussic
acid!” when he expired,—not more than five minutes after leaving the
shop. On the floor of the cellar an ounce-phial was found, which had
been filled with the Bavarian hydrocyanic acid, but contained only a
drachm. It appeared that he had taken the acid ignorantly for an
experiment; and from the state of the articles in the cellar, it was
evident that, alarmed at its instantaneous operation, he had tried to
get at the ammonia, which he knew was the antidote, but had found the
tremendous activity of the poison would not allow him even to undo the
coverings of the bottle.[1907]
When the quantity of the poison is small, a much longer interval may
elapse before the commencement of its action. Thus, when the dose is
barely short of what is required to occasion death, the effects may be
postponed even for fifteen minutes, as in a case which occurred to Mr.
Garson of Stromness.[1908] This, so far as I am at present aware, is the
extreme limit of interval hitherto observed.
In the trial related above the prisoner Freeman was found _Not Guilty_.
It is important to fix, if possible, the smallest fatal dose of
hydrocyanic acid. This will vary with particular circumstances, such as
the strength of the individual, and the fulness or emptiness of the
stomach at the time. The cases of the Parisian epileptics, who were
killed each by a draught containing two-thirds of a grain of pure
acid,[1909] will supply pointed information. For, on the one hand,
considering the long time they survived, it is not probable that a dose
materially less would have a fatal effect on man. And on the other hand
repeated instances of recovery have been observed, where the dose was as
great or even greater. Thus Dr. Geoghegan had a patient who recovered
from a state of extreme danger after taking two-thirds of a grain;[1910]
and Mr. Banks of Lowth met with a case of recovery in similar
circumstances, where the dose was very nearly a whole grain.[1911]
It is almost unnecessary to add, that in man, as in animals, this poison
will act violently, through whatever channel it may be introduced into
the body. It has not been positively ascertained to act with force
through the unbroken skin. The chemist Scharinger indeed was supposed to
have been killed in consequence of accidentally spilling the acid on his
naked arm;[1912] but this was in all probability a mistake. Should the
skin be freely exposed to the air it seems reasonable to expect that the
poison will evaporate before it could act with energy; but if confined
by pledgets or otherwise, a different result might ensue. Through every
other surface, however, besides the unbroken skin, hydrocyanic acid acts
with very great power; and it is in particular important to remember
that its power is very great when inhaled, so that dangerous accidents
have ensued even from its vapour incautiously snuffed up the nostrils. I
have known a strong man suddenly struck down in this way; a French
physician, M. Damiron, has related the case of an apothecary who
remained insensible for half an hour subsequently to the same
accident;[1913] and cases of the kind are more apt to occur than might
at first view be thought, because, contrary to what is generally
believed and stated in chemical as well as medico-legal works, its smell
is for a few seconds barely perceptible, and never of the kind which
these accounts would lead one to anticipate. Accidental death may
readily arise from its action on a wound or an abraded surface.
Sobernheim mentions that Mr. Scharring, a druggist at Vienna, was
poisoned in consequence of a phial of the acid breaking in his hand and
wounding it; and he expired in an hour.[1914]
The only case with which I am acquainted of poisoning with the
artificial compounds of hydrocyanic acid is that formerly alluded to as
having been occasioned by the cyanide of potassium. Six grains dissolved
in a clyster amounting to six ounces, occasioned general convulsions,
palpitations, slow laboured breathing, coldness of the limbs, dilated
pupil, fixing of the eyeballs, and death in one hour,—phenomena much the
same with those produced by the acid itself.[1915]—Another case has been
published, in which a French physician, ignorant of the correct dose,
prescribed a potion with three grains of cyanide of potassium twice a
day. Immediately after the first dose the patient was seized with the
usual symptoms of poisoning with hydrocyanic acid; and expired in
three-quarters of an hour.[1916] In noticing the first of these cases,
Orfila draws the attention of practitioners particularly to the fact,
that not long before a similar dose of a sample of cyanide, which had
been moist for some time, was twice administered with impunity. The
reason is that the cyanide of potassium undergoes decomposition when
acted on by water, or when long kept.