ACCORDING TO THE DIFFERENT PRIMARY OPERATIONS, BY WHICH THEY PRODUCE
THEIR EFFECTS,
With a view to furnish a General Theorem for the administration of
Antidotes.
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CLASS I. POISONS WHICH ACT PRIMARILY, THROUGH THE MEDIUM OF THE
NERVES, WITHOUT BEING ABSORBED; OR EXCITING LOCAL
INFLAMMATION.
_Order 1._ _By which the functions of the Nervous System are
suspended, or destroyed._
(_Death by Suffocation from paralysis of the
Respiratory muscles._)
Alcohol.
Aconite.
Oil of Tobacco.
Essential Oil of Almonds.[220]
Camphor.[220]
Opium?[220]
Salts of Lead?
Croton Tiglium.[221]
_Order 2._ _By which the heart is rendered insensible to the
Stimulus of the Blood._
(_Death by Syncope._)
Infusion of Tobacco.
Upas Antiar.
CLASS II. POISONS WHICH, BY ENTERING THE CIRCULATION, ACT THROUGH THAT
MEDIUM, WITH DIFFERENT DEGREES OF ENERGY, ON THE HEART,
BRAIN, AND ALIMENTARY CANAL.
(_Death in many forms._)
Arsenic.
Emetic Tartar.
Muriate of Baryta.
Hellebore.
Savine.
Meadow Saffron.
Squill.
Opium?[221]
Lettuce.
Henbane.
Prussic Acid.
Deadly Nightshade.[221]
Hemlock.
Camphor.[221]
Coculus Indicus.
CLASS III. POISONS WHICH, THROUGH THE MEDIUM OF THE CIRCULATION, EXPEND
THEIR ENERGIES UPON THE SPINAL MARROW, WITHOUT DIRECTLY
INVOLVING THE FUNCTIONS OF THE BRAIN.
(_Death by Tetanic Convulsions._)
Nux Vomica—and the whole tribe of
_Strychnus_.
CLASS IV. POISONS WHICH PRODUCE A DIRECT LOCAL ACTION ON THE MUCOUS
MEMBRANE OF THE ALIMENTARY CANAL.
(_Death by Gangrene._)
Corrosive Sublimate.[220]
Verdigris.
Muriate and
Oxide of Tin.
Sulphate of Zinc.
Nitrate of Silver.
Concentrated Acids.
Caustic Alkalies.
Cantharides.
Bryony.
Elaterium.
Euphorbium.
Colocynth.
Hedge Hyssop.
Ranunculi.
Nitre.
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The _First Class_ of our arrangement comprehends such poisons as
operate, through the medium of the nerves, upon the organs immediately
subservient to life; in their application it is obvious that they cannot
require to be introduced into the stomach; they may convey their
destructive influence by an application to any part duly supplied with
nerves, and whose extremities are exposed to their action. It had been
long admitted that a poison might occasion death, by acting on the
nerves of the stomach and intestines without being absorbed; but to the
experimental labours of Mr. Brodie[222] we are principally indebted for
our present correct views of the subject. The class admits of two
important divisions, into one comprehending those poisons which destroy
the functions of the brain, and into another, including those which
direct their influence upon the heart. We shall offer a few observations
upon the facts which have suggested such a division, and upon the
practical advantages which may attend its adoption.
It was observed by _Bichât_, and the observation has been fully
confirmed by _Brodie_, that the influence of the brain is not _directly_
necessary to the action of the heart; and is _immediately_ necessary to
life, only because the muscles of respiration owe their action to its
influence.[223] For when the functions of the brain are destroyed, even
when the head is removed, the heart continues to contract for some time
afterwards, and then ceases only in consequence of the suspension of
respiration, which is under the direct influence of the brain. Assuming
this as a fact, it will appear evident that certain poisons may, by
affecting the brain, so paralyse the muscles of respiration as to
occasion death by suffocation, and by such a mode of operation I imagine
that those substances, arranged in the former division of my first
class, prove mortal. _Mr. Brodie_ accordingly found that, by the
administration of a large dose of alcohol to a rabbit, the pupils of its
eyes became dilated, the extremities convulsed, and the respiration
laborious, and that this latter function was gradually performed at
longer and longer intervals, and that it at length entirely ceased. Two
minutes after the apparent death of the animal, he opened the thorax,
and found the heart acting with moderate force and frequency,
_circulating dark coloured blood_; he then introduced a tube into the
trachea, and produced artificial respiration by inflating the lungs, and
he found that by these means the action of the heart might be kept up to
the natural standard, as in an animal from whom the head is removed. The
same phenomena resulted from the injection of two drops of the
_Essential Oil of Bitter Almonds_, diffused in half an ounce of water,
into the rectum of a cat; and from the application of the empyreumatic
oil of _Tobacco_ to the tongue, and rectum of cats and dogs. Now it is
obvious that the functions of the brain are immediately disordered by
the influence of these poisons on the tongue, stomach, and lower bowels
of animals, so instantaneously, that it is impossible absorption should
have already taken place.
Although the general proposition seems to be established, that the brain
is not _immediately_ necessary to the action of the heart, yet it must
not lead us to the conclusion that the heart is therefore incapable of
being affected by violent impressions on the nervous system; the fact is
quite otherwise, for although the brain may be removed, and the
circulation be nevertheless maintained by artificial respiration, yet an
injury of another kind inflicted on the brain, may be followed by those
immediately fatal consequences which decapitation itself would not
produce; thus is a blow on the head commonly followed by syncope, and
there are certain poisons that would seem to act in the same manner,
such is the _Infusion of Tobacco_,[224] which suspends the action of the
heart long before the animal ceases to respire, and kills by producing
syncope, although in this latter case it has been questioned whether the
spinal marrow may not be primarily affected, which has been shewn by
recent experiments to have an intimate relation with the action of the
heart. Be this as it may, it is sufficiently obvious, that the second
division of the first class is sanctioned by theory, and confirmed by
experiment.
We come now to speak of the Second Class,—of those Poisons which enter
the circulation, and act through that medium on the heart, brain, and
alimentary canal. These organs, however, are affected in very different
degrees by different poisons, or even by the same poisons, under
different circumstances. _Mr. Brodie_ has shewn that vegetable poison,
although when introduced into the alimentary canal affect life, in
consequence of the nervous sympathy which subsists between these
surfaces and the common sensorium, yet, that the same poisons applied
externally to a wound, produce their effects exclusively through the
medium of the circulation, being conveyed to the brain only by mixing
with the blood in its vessels, and not by being conveyed through the
lymphatics, for a ligature upon the great blood-vessels prevents their
producing deleterious effects; whereas a ligature upon the thoracic
duct, or general canal through which all the absorbents pour their
contents into the blood, does _not_ in the least retard or prevent the
operation of the poison. There are also several of the mineral poisons
which, whether introduced into the stomach, or applied externally to a
wound, poison the animal in consequence of being carried into the
circulation. It had long been supposed that Arsenic occasioned death by
inflaming the stomach; but _Mr. Brodie_ has very satisfactorily shewn
that its influence arises from its absorption, and that it must be
regarded rather as a _vital_, than as a _chemical_ agent. In the first
place, he has found the inflammation of the stomach, in several cases,
so slight, that on a superficial examination it might have been easily
overlooked; and, in most of his experiments with Arsenic, death took
place in too short a time to be considered as the result of
inflammation; and in the next place, in whatever manner the poison is
applied, whether _externally_ to a wound, or _internally_ to the
membrane of the stomach, the inflammation is confined to the stomach and
intestines; and, indeed, it is commonly more violent, and even more
immediate, when applied to a wound, than when internally administered;
and it also precedes any inflammation of the wound. This important fact
was proved by an experiment made by Mr. Hunter and Sir Everard Home, and
subsequently by the repeated investigations of Mr. Brodie.
It has been just stated that after a poison has found its way into the
circulation, it expends its virulence upon some particular organs. In
some cases this is much more striking than in others. The preparations
of _Baryta_, and of _Tartarized Antimony_, attack the heart, and
occasion death by syncope. _Arsenic_ is less definite in its action, it
influences both the brain and the heart, but with different degrees of
force in different cases, so that it is often difficult to ascertain
which of these organs is the first to fail in its functions.
_Hydro-cyanic Acid_ is absorbed, and destroys life by its action upon
the nervous system, whose energies it would seem to extinguish without
any ostensible injury to the 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.
Some substances would seem to direct their powers to various parts of
the alimentary canal; and the appearance so produced might be mistaken
for the effects of the local action of the poison, had they not been
clearly proved by experiment to have arisen from an application
addressed through the medium of the circulation; thus is inflammation of
the _primæ viæ_ induced by the contact of Arsenic with an external
surface of the body!
The _Third Class_ of my arrangement includes those poisons which enter
the circulation, and, through that medium, expend their influence upon
the spinal marrow, without _directly_ involving the functions of the
brain. _M. Majendie_, in the year 1809, submitted to the first class of
the French Institute a series of experiments which had conducted him to
the extraordinary result above stated. He found that an entire class of
vegetables (the _bitter Strychnus_) possesses this singular property.
The _Fourth Class_ comprehends all those substances which destroy life
by a local action upon the alimentary canal, not by any impression upon
their nerves, but by simply inducing a fatal lesion in the membranes.
Through one or more of the above modes of operation all poisons may be
said to produce their fatal effects. In some cases a poisonous substance
will be found to act in several different ways; thus, the _Nightshade_
is evidently absorbed, carried into the circulation, and is enabled,
through that medium to act upon the brain; at the same time it exerts a
local action upon the stomach, although less violent than that
occasioned by the acrid poisons; it moreover would appear, upon some
occasions, to act directly through the medium of the nerves, like those
substances which have been received in our first class, or else, how
shall we explain the fact of the pupil of the eye becoming permanently
dilated by the contact of the _Belladonna_ with the tunica conjunctiva?
It would appear therefore that this plant unites within itself all the
three great modes of action, upon which I have just attempted to
establish a physiological arrangement of Poisons. So again, _Corrosive
Sublimate_, although placed in the fourth division, as being a substance
which destroys by inflicting local mischief, is nevertheless capable of
being absorbed. The embarrassments, however, which might be supposed to
arise from this double mode of operation, are of but trifling
importance. It is to the primary operation of a poison to which we are
to direct our attention, the subsequent effects are less important in as
much as they are more capable of being controlled.
Having thus offered a summary of our present views respecting the
physiological action of Poisons, we are prepared to lay down a general
plan of treatment, which, it will be seen, can only be successful when
conducted on principles strictly conformable with the just notions which
the preceding experiments have so satisfactorily established.
Where a poisonous substance has, either through accident or design,
found its way into the alimentary canal, three important indications
are, if possible, to be fulfilled; and under these heads I shall offer
such observations as may serve to instruct the practitioner in the
philosophy of the general treatment, reserving the details to be
observed in that of each poison, for more particular notice in a
subsequent part of the work, where the history of these substances will
be individually considered. The indications to which I allude are the
following, viz.
1. _The immediate ejectment of the poison from the body, by the
operation of vomiting and purging._
Whatever may be the nature of the poison, we should endeavour with all
possible expedition, to eject it from the body; and upon the promptness
with which this is effected, the safety of the patient will generally
depend; for the dangerous effects of such substances advance in a very
increasing ratio, with the time they remain in contact with a living
surface. A question may arise, whether in some cases it would not be
judicious to attempt in the first instance the neutralization or
decomposition of the poison; where a mineral acid, or a caustic alkali
has been swallowed, it would undoubtedly be right to neutralize, and
dilute it, as soon as possible, and then to excite vomiting, which may
be advantageously effected by thrusting the finger down the throat, or
by tickling the internal fauces with a feather: where an emetic is at
hand, whatever may be its nature, it should be promptly given, but if
circumstances will allow us the opportunity of selection, _Antimony_,
_Ipecacuanha_, &c. should be rejected, and _Sulphate of Zinc_, or
_Sulphate of Copper_, for several reasons, be preferred; in the first
place they do not require much dilution[225] for their action, a
circumstance of no small importance in the treatment of poisons that act
by being absorbed; in the next place, they are extremely expeditious, a
dose of fifteen or twenty grains producing almost instantaneous
vomiting, without exciting that previous stage of nausea which so
frequently characterises other emetics, and which occasions a state of
the vascular system highly favourable to the function of absorption, (as
I have so fully explained at page 86, &c.)
The practice of emptying the stomach by means of a syringe, as proposed
by Boerhaave, has lately been revived with all the confidence of a _new_
invention. There are cases of narcotic poisoning in which there can be
no doubt it would furnish the practitioner with a valuable resource, but
I much fear that it will be found to be less successful than its more
sanguine advocates have anticipated; for where the stomach has so far
lost its power as to be insensible to the stimulus of a potent emetic,
the chances of recovery are small; the practice, however, in such cases
ought never to be neglected, for it cannot possibly do harm, and may
perhaps be beneficial.
After all has been ejected, which the operations of art can effect, we
are to proceed, without delay, to the fulfilment of the second
indication; viz.
2. _The Decomposition of any remaining Portion, and the adoption of
measures best calculated to obviate its absorption._
Where the substance is in a solid form, and acts by absorption, we
should be very cautious how we favour its solution; while, if it exists
in a liquid state, our object must be to render its active portion
insoluble; this problem involves a series of questions which are wholly
_chemical_. In order to prevent, or retard, the absorption of the active
matter, we must, to a great degree, depend upon the agency of _vital_
adjuvants; this latter indication however does not apply to _Corrosive
Sublimate_ and other substances which act upon the stomach locally, and
are not absorbed; copious dilution also, in such cases, will frequently
disarm the poison of its virulence,[226] but it should be followed as
quickly as possible by vomiting. In cases where the poison requires to
be absorbed, before it can display its energies, it would be generally
unsafe to administer any solvent. Nothing therefore can be less true as
an aphorism, nor more dangerous as a precept, than the unqualified
assertion of Boerhaave, “_Aqua omnia venena enervat, quæ cum aqua
misceri possunt_.” (Prælect. in Instit: T. vi. p. 289.) _Alkaline_
solutions and _Magnesia_, in cases of the ingestion of arsenic,
accelerate its fatal effects, by promoting its solution,[227] whereas
_Lime_, or its _Carbonate_, has as an opposite tendency,[228] in
consequence of the insolubility of _Arsenite of Lime_; so again, Orfila
has shewn that the pernicious qualities of the _Muriate of Baryta_ are
counteracted by the administration of any soluble _Sulphate_, which
renders the former substance _insoluble_. In cases where _Verdegris_ has
been swallowed, the administration of vinegar greatly increases its
virulence, as M. Drouard has ascertained, by converting the substance
into a soluble _acetate of copper_. This view of the subject will
explain why the pure earth _Baryta_ is so slow, and comparatively inert,
in its effects upon the system, while its _muriate_ is distinguished by
the extreme rapidity and virulence with which it operates. The propriety
of administering _vinegar_, _lemonade_, and different acid potations, in
order to counteract the baneful effects of _Opium_, which has been so
often questioned, will thus also receive ample explanation; it must
appear that, if any quantity of the substance of opium remain in the
primæ viæ, acid, or mucilaginous drinks will, by favouring its solution
and absorption, accelerate its fatal effects;[229] but should it have
been previously ejected from the stomach, that then the anti-narcotic
influence of a vegetable acid[230] may remove the consecutive stupor and
delirium, and thus realize the expectations which Virgil has so
poetically raised.
“Media fert tristes succos tardumque saporem
Felicis Mali: quo non præsentius ullum
(Pocula si quando sævæ infecere novercæ
Miscueruntque herbas, et non innoxia verba)
Auxilium venit, ac membris agit atra venena.”
“Nor be the Citron, Media’s boast unsung,
Though harsh the juice, and ling’ring on the tongue.
When the drug’d bowl mid witching curses brew’d
Wastes the pale youth by step-dame hate pursu’d,
Its powerful aid unbinds the mutter’d spell
And frees the victim from the draught of hell.”
Chardin, in his travels through Persia, informs us that when a Persian
finds himself in a distressed situation, he has recourse to a piece of
opium as large as the thumb, and that immediately afterwards he drinks a
glassful of vinegar; by which he is thrown into a fit of laughter,
terminating in convulsions and death.
With regard to the use of _Antidotes_, it has been already stated how
little they are to be depended upon; in certain cases, however, we are
bound to acknowledge their power, but they should be very rarely
trusted, unless subsequent to, or in conjunction with, the operation of
an emetic; in many cases the effects of this latter remedy may be
promoted by the ingestion of liquids holding the particular antidote in
solution, a practice which offers the double advantage of accelerating
the elimination of the poison, and at the same time of decomposing any
which may remain. Orfila has fully established the fact of _Albumen_
being a counter-poison to _Corrosive Sublimate_; vomiting may therefore
be very judiciously promoted in cases of such poisoning by water holding
the white of egg in solution; with equal effect, where _Verdegris_ has
been swallowed, sugared water may be used as a diluent to encourage
emesis; and _Muriate of Soda_ in solution will be found the most
efficient antidote to _Nitrate of Silver_; and _Sulphate of Magnesia_ to
_Acetate of Lead_. Where an emetic salt, like _Tartarized Antimony_, has
been taken, copious dilution with common water will in general so
provoke vomiting, as to render it its own antidote; but it may be useful
to remember, that the _Infusion of Galls_, and according to Berthollet,
the _Decoctions of Bark_, at the temperature of from 30° to 40° _Fah._
have the power of decomposing it; while Orfila considers milk the most
efficient counter-poison to the _Sulphate of Zinc_.
Having ejected from the stomach all the poisonous matter we can by
vomiting, and attempted to decompose what remains, we are to pursue such
measures as may be calculated to prevent the absorption of the poison
into the circulation; it has been already observed that on this account
nauseating emetics should be avoided; the reader is now requested to
refer to our _exposé_ of the celebrated doctrine of _Majendie_, (_page
86_, _note_) and he will see that _Venesection_ proves one of the most
powerful means of exciting the function of absorption; hence in
poisoning by arsenic, such an expedient should never be
recommended,[231] while a particle of that substance remains in the
body; where _Corrosive Sublimate_ has been swallowed, the same
precaution is unnecessary. The last indication which remains to be
fulfilled is—
3. _To anticipate the occurrence of the Consecutive Phœnomena, and to
combat them by appropriate treatment._
This is to be conducted on the general principles of Therapeutics; the
treatment must necessarily vary in each particular case. Where the
exhaustion of nervous energy is to be feared, as after poisoning by
_Prussic Acid_, ammonia, and other diffusible stimulants, together with
external warmth, will furnish the best resource; for the same reason
Venesection should be performed with great caution and judgment after a
narcotic poison. Where, on the other hand, inflammatory action is to be
anticipated, it is unnecessary to detail the plan of treatment which may
be adopted with the greatest chance of success. In cases where the
nervous system is stupified, the symptoms may be combated by vegetable
acids, infusion of coffee, &c. but where it is in a state of
præternatural excitement, recourse must be had to opiates.