The LAUREL (_Prunus lauro-cerasus_) and its distilled water. BITTER
ALMONDS, and their essential oil.
Hydro-cyanic acid exists in a great variety of native combinations in
the vegetable kingdom, and imparts to them peculiar qualities, which
have been long known. It is, however, only within a few years, that this
singular body has been obtained in its separate and independent
form[432]; indeed it was not until the publication of the celebrated
memoir of _Gay-Lussac_ upon this subject, in the year 1815, that its
chemical composition was fully understood. In this memoir, it was
clearly shewn to consist of a peculiar, gaseous, and highly inflammable
compound of carbon and nitrogen, to which the name of _cyanogene_ has
been assigned, and hydrogen; the latter body acting as the acidifying
principle; whence the term _hydro-cyanic acid_ is very happily contrived
to express its composition.
When obtained in its most concentrated form, by the process of _M. Gay
Lussac_,[433] it has the following characteristic properties, viz. At
ordinary temperatures, it is liquid, colourless, and transparent;
possessing an extremely powerful odour, very analogous to that of the
blossom of the peach, or bitter almond tree; its taste is, at first,
bland and sweetish, but afterwards pungent, bitter, and peculiar. Its
extreme volatility is such, that when a drop of it is exposed to the
air, on the end of a glass rod, it is rapidly crystallized. The same
phenomenon takes place, if a drop be suffered to fall on a sheet of
paper. Its specific gravity is ·7055; but, when in a concrete form it is
only ·9, while that of its vapour is ·947. If inhaled, it produces
almost immediate pain in the head, with deafness, unless very largely
diluted with air or water.[434] It is decomposed by a high temperature;
and by the action even of light it is, in the course of a very short
time, resolved into carbonic acid, ammonia, and carburetted hydrogen, a
carbonaceous matter remaining behind.[435] When brought near a body in a
state of combustion, it instantly inflames and burns with a blue light.
In water it is sparingly soluble; alcohol dissolves it copiously.
The “_medicinal Prussic acid_,” as it has been called, as being the
preparation lately introduced into medicine,[436] differs only from that
we have just described, in its degree of concentration. It is, in fact,
the Prussic acid of _Scheele_, and may be considered as equivalent to
the preparation of _Gay-Lussac_ diluted with six times its volume, or
eight times and a half its weight, of distilled water.
The _hydro-cyanic acid_ has been discovered, in a state of perfect
formation, in a variety of vegetables, whose peculiar odour at once
announces its presence; such are bitter almonds; the kernels of
apricots, cherries, particularly the _Cerasa Juliana_, and several
plums; the leaves of laurel; and peach blossoms; and the bark of the
_prunus padus_, or bird-cherry tree. The only mineral substance, in
which hydro-cyanic has yet been detected is the _Fer Azuré_ of
Hauy.[437] Animal substances, although they do not contain it ready
formed, yet, when treated with an alkali at a high temperature, they
yield it in great abundance, in consequence of the combination of its
elements.
_Action of hydro-cyanic Acid as a Poison._
The experiments which have been instituted with a view to ascertain the
exact effects of this substance upon animal life, very clearly prove
that the acid of _Gay-Lussac_ is one of the most active poisons in
nature; and that the various vegetable bodies, into whose composition it
enters, exert an energy, corresponding with the quantity of this
constituent, and the degree of concentration, in which it exists. The
experiments of _M. Orfila_ were made with Prussic acid, prepared
according to the process of _Scheele_, and consequently containing a
great proportion of water, as we have already explained; and yet the
effects which followed its administration were extremely energetic. From
the _Annales de Chimie_, for October 1814, we learn that a professor of
chemistry, having inadvertently left on his table a phial filled with a
solution of Prussic acid in alcohol, a female servant, who had been
seduced by its agreeable smell, drank a small glass-full of it, and fell
dead at the end of a few minutes, as if struck by apoplexy.
The following case is quoted by _Dr. Granville_, from _Hufeland_. _D.
L._ a robust and healthy man, aged 36 years, while about to be seized as
a thief by the police officers, snatched a small sealed phial from his
pocket, broke off the neck of it, and swallowed the greatest part of its
contents. A strong smell of bitter almonds soon spread around, which
almost stupefied all present. The culprit staggered a few steps; then,
without a groan, fell on his knees, and sunk lifeless down to the
ground. Medical assistance being called in, not the slightest trace of
pulse or breathing could be found. A few minutes afterwards, a single
and violent expiration occurred, which was again repeated in about two
minutes. The extremities were perfectly cold, the breast and abdomen
still warm, the eyes half open and shining, clear, lively, full, almost
projecting, and as brilliant as those of the most ardent youth under
violent emotion. The face was neither distorted nor convulsed, but bore
the image of quiet sleep. The corpse exaled a strong smell of bitter
almonds, and the remaining liquid, being analysed, was found to be a
concentrated solution of Prussic acid in alcohol. Cases also stand
recorded where, from imprudent exposure to the vapours of the Prussic
acid, persons have exhibited all the appearances of being poisoned. Some
writers assert that _Scheele_ himself, who died suddenly, while engaged
in some inquiries into the nature and formation of this acid, was
affected by its deleterious qualities. _Orfila_ relates that
_Scharinger_, Professor at Vienna, prepared some pure concentrated
Prussic acid, and having diffused a certain quantity of it upon his
naked arm, he died a short time afterwards. The professor, however, did
not die in consequence of this accident; it appears, upon inquiry, that
he was seized with apoplexy while sitting in a coffee house in the
evening.
The distilled water of the _cherry laurel_[438] has been proved, by
numerous awful examples, to be a most energetic poison; and from the
fatal effects to which the officinal preparation of it gave rise, it was
early expunged from the Pharmacopœia of the London College. In the
_Philosophical Transactions_ for the year 1731, we shall find the
history of its effects upon a woman of the name of _Boyce_, who, with a
view to disprove an allegation, that one _Mary Whaley_ had died in
consequence of drinking a small quantity of laurel water, swallowed
three spoonsful, and, afterwards, two more of the same liquid; after
which she died in a very short time, without making the least complaint,
and without any convulsion.
_Foderé_ informs us that during the period he was pursuing his studies
at Turin in 1784, the chambermaid and man servant of a noble family of
that town, for the purpose of regaling themselves, stole from their
master a bottle of distilled laurel water; fearful of being surprised,
they hastily swallowed several mouthsful of it; but they soon paid the
price of their dishonesty, having almost instantly expired in
convulsions. Works on Toxicology also abound with the relation of
experiments, made by numerous physiologists on different animals, with
this deleterious liquid. Amongst the experimentalists we may enumerate
the names of _Madden_, _Mortimer_, _Browne_, _Langrish_, _Nicholls_,
_Stenzelius_, _Heberden_, _Watson_, _Vater_, _Rattrai_, the _Abbé
Rozier_, _Duhamel_, _Fontana_, and _Orfila_. In this country we have had
several fatal cases of poisoning by laurel water. In the year 1782, _Dr.
Price_, of Guildford, having professed to have converted mercury into
gold, offered to repeat his experiments before a competent tribunal, but
the unfortunate philosopher put a period to his existence before the day
appointed for his exhibition, by a draught of laurel water; a mode of
death which had been, no doubt, suggested by the celebrated trial of
_Donellan_, for the murder of _Sir Theodosius Boughton_, that had taken
place in the preceding year, and left a strong impression upon the
public mind; and whose details, it has been justly observed, are not
more important from the elucidation of the effects of this poison, than
from the strange display of professional testimony to which it gave
origin, (see _Appendix_, page 243.) There are those who still profess to
believe that the prisoner was unjustly convicted upon that occasion;
_Dr. Male_ states, without the least reserve, that it was neither proved
that the deceased was poisoned, nor that any poison had existed.[439] We
feel no difficulty in declaring that we hold a directly opposite
opinion; and we consider that many of the weaker points of professional
evidence delivered on the trial, have received powerful support and
elucidation from the experiments and observations of later physicians.
Nor are the leaves of this plant wholly free from danger; it is true
that they have, for many years, been in general use among cooks, to
communicate an almond or kernel-like flavour to custards, puddings,
creams, _blanc-mange_, and other delicacies of the table; but the custom
has not always been harmless; a fact with which it behoves the forensic
physician to be acquainted. In some parts of the continent milk is
boiled with one or two leaves of the cherry-laurel in it, and
_Ingenhouz_ states that he saw people much affected by it. In the
_Literary Chronicle_ (no. xxii, p. 348, 1819) we find the following
illustrative case: “Several children at a boarding-school, in the
vicinity of Richmond, having partaken of some custard flavoured with the
leaves of the cherry-laurel, four of them were taken severely ill in
consequence. Two of them, a girl of six, and a boy of five years of age,
fell into a profound sleep, out of which they could not be roused for
ten hours, the other two complained of severe pains in the epigastric
region. By proper medical treatment, they all recovered, after an
illness of three days.”
The essential oil of _bitter almonds_ is equally poisonous; and the
water distilled from them is highly dangerous if incautiously taken.
_Duvignau_ and _Parent_ instituted some experiments upon themselves to
ascertain this fact; they commenced by taking six drops of the water
distilled three times, in an appropriate vehicle, without producing any
other than a transient impression. On taking _eighteen_ drops, however,
vertigo was experienced, and a disposition to sleep, accompanied with a
tingling of the ears and dimness of sight. When the dose was increased
to _twenty-two_ drops, alarming symptoms followed, such as convulsions,
and vomiting; which, although the experimenters succeeded in allaying by
antispasmodics, cured them completely of any ulterior wish to ascertain
how far this substance might be deleterious. A drachm of the distilled
water of bitter almonds has killed a moderate sized dog. The _essential
oil_ is proportionally more active; _Mr. Brodie_[440] found that one
drop, when applied to the tongue of a cat, killed it in five minutes; no
sooner did the poison come in contact with the organ than the animal was
seized with convulsions. When two drops of the same oil were injected
with half an ounce of water into the rectum of a cat, it was not seized
for two minutes, but it died, as in the former experiment, after the
expiration of five minutes. While engaged in this inquiry, _Mr. Brodie_
dipped the blunt end of a probe into the essential oil, and applied it
to his tongue, with the intention of tasting it, and not having the
least suspicion that so small a quantity could produce any of its
specific effects on the nervous system; but scarcely had he applied it,
when he experienced a very remarkable and unpleasant sensation, which he
referred chiefly to the epigastric region, but the exact nature of which
he could not describe, because he knew nothing similar to it. At the
same time there was a sense of weakness in his limbs, as if he had not
the command of his muscles; and he thought that he should have fallen.
The fascinating liqueur noyau, _créme de noyau_, is indebted for its
flavour to the essential oil of the bitter almond, or peach; and is
undoubtedly deleterious if taken in excess. In the _Journal des Debats_,
for 1814, we find that the late _Duke Charles de Lorraine_ had nearly
lost his life from swallowing some drops of _eau de noyau_ too strongly
impregnated with the essential oil of peach kernels.
The bitter almond itself, in consequence of the manner in which its
deleterious principle is modified by the natural state of combination in
which it exists with sweet oil and albumen, does not produce an effect
corresponding with the proportion of essential oil which it yields. The
experiments of _Orfila_, however, prove that the almond, in doses of a
drachm, is destructive to cats; and there can be no doubt but that it
would be equally deleterious to the human species; but the quantity
required for the production of such an effect must ever prevent the
bitter almond from becoming either the accidental or criminal instrument
of death.
_Physiological action of Prussic acid._
The numerous experiments, which have been made with this poison, have
clearly established that its action is upon the nervous system, whose
energies it would seem to extinguish without any ostensible injury to
respiration and circulation; for in all those animals which were killed
by it, in the experiments of _Orfila_, _Brodie_, and others, the heart
was found acting regularly, and circulating dark coloured blood, and in
some cases this phenomenon was visible for many minutes after the animal
was in other respects apparently dead. _Orfila_ considers that he has
fully demonstrated that these effects depend on the absorption of the
poison, and its transmission to the brain through the medium of the
circulation. We have accordingly placed Prussic acid in the second
division of our classification. The essential oil of bitter almonds
would, according to the experiments of _Mr. Brodie_, appear to act
through the medium of the nerves, and it has accordingly been referred
to our first division. This is undoubtedly an anomaly, which it is not
easy to reconcile; the experiments, however, which led _Mr. Brodie_ to
the conclusion appear to us to warrant such a deduction; the
instantaneousness with which the poisonous effects were produced, and
the fact of its acting more speedily when applied to the tongue, than
when injected into the intestines, although the latter presents a better
absorbing surface, seem to oppose the idea of the oil requiring to be
absorbed, before it can display its energies. _M. Vogel_, of Munich, has
lately discovered some facts respecting the composition of this oil,
which may perhaps hereafter lead to the true explanation of this
apparent anomaly; this distinguished chemist succeeded in separating the
Prussic acid from the volatile oil with which it is combined, by
agitating the whole in a concentrated solution of potass, and distilling
to dryness; the oil volatilized together with the water, while the
residuum in the retort was found to contain _cyanide of potassium_. The
oil, thus separated from the Prussic acid, is without odour, and heavier
than water; its taste is extremely acrid and burning; in order to
discover whether it was still poisonous, _M. Vogel_ put a drop of it on
the tongue of a sparrow, when it died in a few seconds, after a very
violent convulsion; he also poisoned a dog, two months old, with four
drops of it; whence he concludes that the volatile oil, divested of its
hydro-cyanic acid is still a poison, although less energetic than that
which has not undergone such a change. Do there exist then two
independent principles of activity in the _bitter almond_? If such a
fact were established it would not be solitary, for we shall hereafter
shew that the energies of _tobacco_ are dependant upon an analogous
arrangement; and that our ignorance of the fact, at first, occasioned
apparent anomalies, as embarrassing as those which at present involve
the physiological history of the oil of almonds.
_Antidotes._
_Orfila_, in his celebrated Toxicology, informs us that vinegar, or the
vegetable acids; coffee; a solution of chlorine in water; camphor;
emollient drinks; and bleeding, have been successively, but not
successfully recommended.[441] With respect to the first of these
pretended _antidotes_, it deserves notice, that instead of palliating
the symptoms, it actually quickens, and gives more energy to the action
of the poison. Coffee, as far as it may stimulate, might be employed
with advantage; but its powers are not sufficient to meet the exigency
of the case. Bleeding seems decidedly a fatal measure. The authors of
the paper on Prussic acid, inserted in the _American Recorder_, consider
at length the claims of every substance which has been proposed as an
antidote to it; and they conclude by saying that, we are entirely
ignorant of a counter-agent of this poison. There is every reason, says
_Dr. Granville_, to believe that the Prussic acid taken in large
quantities, and in its concentrated state, is partially, if not wholly
absorbed ere it _reaches the stomach_;—else how happens it that scarcely
a minute after its exhibition, I have, in common with others, been
unable to detect its presence within that organ. If so, then all
chemical attempts must be nugatory, no decomposition, or fresh
combinations can be produced to render it harmless; nor will an emetic,
although so much recommended, be of much more service in freeing the
system of its presence. But although chemical remedies are thus shewn to
be of no avail, we may derive from the class of vital agents some
powerful antidotes; all medicines taken from the class of diffusible
stimuli will be useful in supporting the powers of the system against
the sedative influence of the poison. Hot brandy and water, with
ammonia, camphor, and other similar stimulants, are the resources to
which we should fly upon such occasions.
_Organic lesions discovered on Dissection._
The recorded dissections of persons, who have been poisoned by Prussic
acid, are too few and vague to furnish any satisfactory generalization.
In the case related by _M. Foderé_, of two servants who died after a
draught of laurel-water, the dead bodies were carried to the University
at Turin, and examined, when the stomach was found slightly inflamed,
but the other parts were in a sound state. We feel much hesitation in
giving credit to this report, the death was too immediate to allow the
access of inflammation; we are rather disposed to consider the
appearances of the stomach to have arisen from that species of
sanguineous congestion, which we have before alluded to, as sometimes
occurring in cases of sudden death. In other cases the coats of the
stomach are said to have been black and relaxed; the vessels of the
brain injected; the lungs have also been described as presenting
unnatural congestions, and purple spots; and the smell of Prussic acid
seemed as if it pervaded the whole system, and was embodied, as it were,
with the very substance of the muscles. In other cases, again, not the
slightest trace of any morbid appearance could be discovered. Some
authors have stated that in cases of death by this poison the cornea of
the eye does not collapse, but retains its fulness, and even its lustre,
for a considerable period.
_Chemical processes by which the presence of hydro-cyanic acid may be
ascertained._
The strong odour yielded by the body on dissection, will furnish a
satisfactory proof of the presence of this poison. Instances may occur,
when the practitioner will be called before a tribunal to answer, from
his professional knowledge, whether a particular case of death can have
happened from the action of the hydro-cyanic acid, or any of the
compounds in which it may enter as an ingredient; it therefore becomes
an object of great importance to inquire whether any farther tests might
be made subservient to our purpose. _Dr. Granville_, who has directed a
great share of his attention to the history of this poison, has given
some directions upon this point, which appear to us to be useful and
judicious; we shall, therefore, present them to our readers. “After
collecting the blood contained in the ventricles of the heart, a portion
of the contents of the stomach, and of the superior intestines, together
with a certain quantity of any fluid which may chance to be present
within the cavity of the head, chest, or abdomen; and having agitated
the mixture for some time in distilled water, and filtered the liquid,
taking care to keep the whole at a low temperature, proceed to the
following experiments.
A. To a small quantity of the liquid add a few drops of a solution of
caustic potass in alcohol.
B. To this, a few drops of a solution of sulphate of iron must be
added, when a cloudy and reddish precipitate, of the colour of burnt
_Terra-Sienna_ will fall down.
C. Some sulphuric acid is now to be introduced into the tube, when the
colour of the precipitate will instantly change to that of a
bluish-green, which by a permanent contact with the atmosphere,
becomes gradually of a beautiful blue, assuming at the same time a
pulverulent aspect.