A Mechanical Account of Poisons in Several Essays

by Richard Mead

And tho’ this Theory may perhaps appear extravagant, because new and uncommon, yet it will not, I believe, seem ill grounded or irrational to those who understand the Doctrine of the Mixture of Heterogene Fluids, and their Separation; and who withal know, that the Vessels are rarely obstructed, unless it be from the fault of the Liquid they carry, and consequently that a Defect in the Bile it self must be (excepting some extraordinary Cases) antecedent to the Obstruction of the Biliary Ducts.

In short, the different Cure of this Disease confirms these Notions; for an Icterus from the first Cause assign’d, which is generally owing to a sedentary Life, want of Exercise, &c. and attended with an extreme Costiveness and white Fæces, is cured by Volatile, Acrimonious, and Bitter Salts. From the Second produced oftentimes by drinking strong Liquors, Spirits, &c. and accompanied with a Diarrhœa, partly by Diluting and Temperating, partly by Stomachic and Strenghning Medicines. As the last Species of it (for the sake of which we have mention’d the other) is removed by such Antidotes as overcome and destroy the Venomous Ferment, corrupting the Blood, and breaking its Compages. But to have hinted these things may abundantly suffice for the present.

We must however take Notice, That tho’ the main Alterations made by this Poison be in the Fluid of the Arteries, yet that That of the Nerves may hereby be considerably changed too; for This consisting, as well as the Blood of differing Parts, and being dispersed in small Tubes all over the Body, is not only very capable of various Degrees of Force, Impulse, &c. but Undulating continually towards the Brain, and being the chief Instrument of Motion and Action, may perhaps sometimes more immediately convey the Mischief to the sensile Membranes, and thus be the Cause of those violent Pains, Convulsions, Sickness, &c with which Those who are Bitten are presently seiz’d.

Many are the Experiments I could relate to evince the Truth of this Reasoning concerning the Viperine Venom, which do entirely agree with those made by S^r Redi, whose Judgment and Sincerity in Observations of this Nature no Body ever called in Question, till Monsieur Charas having espous’d a Notion, that this Poison does not lie in the Yellow Liquor of the Gums, but in the enraged Spirits of the Viper, rais’d new Difficulties about the Success of some Trials made in France, endeavouring thereby to invalidate the Force and Authority of those made in Italy.

I shall therefore, in order to put this Matter out of all doubt, mention Two or Three Experiments made by Dr. Areskine, when at Paris, that it may appear how defective those of Mr. Charas are, and that the Difference of the Climate does not (as some began to imagine [(16)]) make any considerable Alteration in the Effects of this Venom, or its manner of Killing.

First then, having got a large Female Viper, he made it to Bite Six Pigeons, one after another; the First and Second that were bit, died within about half an Hour, one a little Time before the other; the third liv’d about two Hours; the Fourth seem’d to be very sick, but recovered; the Fifth and Sixth were no more hurt than if they had been prick’d with a Pin or Needle.

Then he cut off the Head of a brisk Viper, and let it lie twenty four Hours, with the Fangs of which he wounded One Pigeon in the Breast, and another in the Thigh, which both expired as soon after, as if they had been biten by a living Viper. After this, having got a great many Vipers together, he made them bite upon a peice of Glass of a Cylindrical Figure, by this means preserving the Yellow Juice which they emitted, and slightly wounding two Pigeons, he first let the Bleeding be stopt, then put some of this Liquor into the Wounds, upon which both the Pigeons died about two Hours after.

The same Ingenious Person tells me, that Monsieur du Verney made not only These, but also several other Experiments of the same Nature, in the Royal Acamy, with the like Success.

These Proofs are so convincing and full, that no one, I think, can desire more; but they will receive yet a farther Confirmation from the Apparatus or Mechanism of the Organs, with admirable Nicety contrived for the Discharge of this Venom, of which more by and by.

Nor is it any Objection against all This, that the Liquor is innocent and harmless in the Mouth or Stomach of any one, so as that it may be safely tasted or sucked out of the Wound, and swallowed; for, as we observ’d before, that many Acid Substances taken into the Stomach are by the Action of that Part turned to Alcalious, so there is no Question but these Saline Spicula are partly by the Muscular Force of the Fibres, partly by the Salival Juice, all broken and dissolved; or if any can pass into the Intestines, the Balsam of the Bile will be an Antidote for Them; the Reason of which will appear when we come to the Cure.