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