For upon the Sense of a violent Irritation and Pain, the Fluid of the Nerves is presently in large quantities determined to the Part affected; and this, if the Stimulus be not over great, will be only to such a Degree as is sufficient, by contracting the Fibres of the Stomach, and Muscles of the Abdomen, to throw off the Cause of the Disagreable Sensation; but the uneasie Twitching being too terrible to be born, the Mind, by a kind of surprize, does with Haste and Fury as it were Command the Spirits thither; Thus the Business is over-done, and the Action of the Fibres becomes so strong, that the Orifices of the Stomach are quite closed; so that instead of discharging the Noxious Matter, The Torment is made greater, and the whole Œconomy put into Confusion.
This forcible Contraction of the Muscles was the Reason that one of the Children which Wepfer saw, made Urine in the midst of the Agony, to the height of Five or Six Foot, with a strength and violence Surprising to the Spectators.
Nor is it any wonder, if in these Circumstances all Sense be lost, Blood gush out at the Ears, Nostrils, &c. the Parts being all torn and broke by the Violence of the Convulsions; which tho’ they began in the Muscles of the Belly, must at last prevail in the Members too, till the whole Fabrick is shock’d and overturn’d; and some of the Corrosive Salts perhaps getting into the Blood, and by the Rarefaction of It Distending the Vessels, The Membranous Coats of which being already overstretched, will the more easily give way, and let out their Fluid.
The Case of Aconitum is much the same; this is our Napellus or Monkshood; and its Effects do so nearly agree with those now related of Œnanthe, that I shall not need to recite Them; the Experiments of Wepfer [(145)] are full and convincing. And indeed as all the Histories which this same Author has so carefully given Us of Trials made with several Vegetable Poisons, Solanum, Nux Vomica, Coculus Indicus, &c. on different Creatures, do put it out of all doubt, that the common Mischief of These is a Twitching and Inflammation of the Stomach; so it appears from hence, that Virulent Plants, although they may be distinguished even from one another by particular Virtues, do however Kill by a like Operation and Force, which differs chiefly in Degree from That of Noxious Minerals.
And therefore in order to know what the Specifick Qualities of any such Herbs are, they must be given only in very small Doses; and then perhaps it would appear, that they are not made (as some do imagine) to be Deleterious and Destructive, but for very Good and Beneficial Uses; as we do particularly Experience in the Case of Opium.
Nor is it at all strange, that the Symptoms from a Vegetable, and from a Mineral Virulency, should be so different, although of the same kind, and only of unequal force; for the more solid Parts of Minerals, eroding the Coats of the Stomach, induce a perfect Mortification and Gangrene, and thus do their Work at once; whereas the weaker Salts of Plants can make but a slighter Excoriation, upon the painful Sense of which those Agonies and Convulsions that follow do rather gradually exhaust the Strength; and thus the Animal is not kill’d so speedily, nor with the same Appearances.
Upon this Score, tho’ Mineral Poisons do not pass the Primæ Viæ, Vegetable ones in some Cases possibly may; just as We find Those Medicines which have a great Degree of Irritation presently to induce a Vomiting; whereas the same Twitching a little weakened suffers them to pass into the Intestines, and Work downwards by Stools.
By this We may perhaps give some Guess at the Nature of those Poisons, with which They tell Us the Natives in some Parts of Africa and India are so expert at Killing, that they can do It in a longer or shorter time as they please. These are most probably either the Fruits, or the Inspissated Juices of Corrosive Plants, which inflaming the Bowels, may cause little Ulcers there, whose Fatal Consequences, we know, may very well be slow and lingering.
This I am the rather induced to believe, because an Ingenious Surgeon, who liv’d in Guinea, told Me, that the Antidote by which the Negroes would sometimes Cure Those who were poisoned, was the Leaf of an Herb which purged both upwards and downwards. For by this means the Stomach might be cleared from the adhering Corrosive Parts of the Venom. Yet I can hardly think it possible at the same time that they should be able, by varying the Composition or Quantity of the Dose, to ascertain the Time in which It shall Kill, to a Week, Month, &c. nor indeed have I ever met with any Person who could Attest This, to be Matter of Fact.
Tho’ repeated Trials and Observations may help one well practised in such Tricks to give notable Conjectures in this Point.