Читать книгу Pharmacologia - John Ayrton Paris - Страница 68

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—