3. The dispute is of no consequence, and the experiment will prove the same thing whether we suppose the poison to act upon the irritable fibre (the nerves and muscles) or upon the blood. The only important point to be ascertained is, whether there be in nature any substance which, applied to the internal parts of the body, or to a wound, will instantly disorder the whole in such a manner as to bring on a violent disease which may prove mortal in a short time. If any such there is, that substance, whether solid or fluid, visible or invisible, may with propriety be called _contagion_; and if any such proceeds from the body of a diseased person to one in health, the vapour so proceeding is _infection_. As to the _mode_ of its operation we are little concerned; the sudden manner in which people are affected shows that poisons kill by suppressing in a very short time the principle of life, which seems to be analogous to electricity, or rather the very same with it; neither is it more incredible that the poison of a serpent should kill by disturbing the natural electricity of the body, than that the stroke of a torpedo, or electrical eel, should kill by the same means. The only difference is, that, in the case of poisons, the pernicious substance is introduced into the body itself; in the torpedo, it comes with violence from without. The former we may compare to the silent discharge of an electrified jar by a point, the latter to its discharge with a violent flash by a knob. But that in poisonous bites the blood is greatly affected, and that in a very short time, we certainly know. There are some kinds of serpents whose bites are so suddenly fatal, that no cure can be applied: one of these, called the small _laharra_, is mentioned by Mr. Bancroft in his Natural History of Guiana. Mr. D’Opsonville, in his Philosophic Essays, takes notice of one in the East-Indies, which he calls the _poison serpent_ or _serpent poison_, which seems to be as bad as the _laharra_ mentioned by Bancroft. This too is but small, viz. two feet long, and very slender. Its skin is freckled with “little traits of brown, or a pale red, and contrasted with a ground of dirty yellow: it is mostly found in dry and rocky places, and its bite proves mortal in less than one or two minutes. In the year 1759, and in the province of Cadapet, I saw several instances of it; and, among others, one very singular, in the midst of a corps of troops, commanded by M. de Bussy. An Indian Gentoo merchant perceived a Mahometan soldier of his acquaintance going to kill one of these reptiles, which he had found sleeping under his packet. The Gentoo flew to beg its life, protesting that it would do no hurt if it was not first provoked; passing at the same time his hand under its belly, to carry it out of the camp; when suddenly it twisted round, and bit his little finger; upon which this unfortunate martyr of a fanatic charity gave a shriek, took a few steps, and fell down insensible. They flew to