[Footnote 1: For an account of the encounter between the ichneumon and the venomous snakes of Ceylon, see Pt. II. ch. i. p. 149.]
As to the snake-stone itself, I submitted one, the application of which I have been describing, to Mr. Faraday, and he has communicated to me, as the result of his analysis, his belief that it is "a piece of charred bone which has been filled with blood perhaps several times, and then carefully charred again. Evidence of this is afforded, as well by the apertures of cells or tubes on its surface as by the fact that it yields and breaks under pressure, and exhibits an organic structure within. When heated slightly, water rises from it, and also a little ammonia; and, if heated still more highly in the air, carbon burns away, and a bulky white ash is left, retaining the shape and size of the stone." This ash, as is evident from inspection, cannot have belonged to any vegetable substance, for it is almost entirely composed of phosphate of lime. Mr. Faraday adds that "if the piece of matter has ever been employed as a spongy absorbent, it seems hardly fit for that purpose in its present state; but who can say to what treatment it has been subjected since it was fit for use, or to what treatment the natives may submit it when expecting to have occasion to use it?"
The probability is, that the animal charcoal, when instantaneously applied, may be sufficiently porous and absorbent to extract the venom from the recent wound, together with a portion of the blood, before it has had time to be carried into the system; and that the blood which Mr. Faraday detected in the specimen submitted to him was that of the Indian on whose person the effect was exhibited on the occasion to which my informant was an eye-witness. The snake-charmers from the coast who visit Ceylon profess to prepare the snake-stones for themselves, and preserve the composition as a secret. Dr. Davy[1], on the authority of Sir Alexander Johnston, says the manufacture of them is a lucrative trade, carried on by the monks of Manilla, who supply the merchants of India--and his analysis confirms that of Mr. Faraday. Of the three different kinds which he examined--one being of partially burnt bone, and another of chalk, the third, consisting chiefly of vegetable matter, resembled a bezoar,--all of them (except the first, which possessed a slight absorbent power) were quite inert, and incapable of having any effect exclusive of that on the imagination of the patient. Thunberg was shown the snake-stone used by the boers at the Cape in 1772, which was imported for them "from the Indies, especially from Malabar," at so high a price that few of the farmers could afford to possess themselves of it; he describes it as convex on one side black, and so porous that "when thrown into water, it caused bubbles to rise;" and hence, by its absorption, it served, if speedily applied, to extract the poison from the wound.[2]