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 to preserve the composition a secret. Dr. Davy[3161], 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 bezoar,—all of them (except the first, which possessed a slight absorbent power) were quite inert, and incapable of having any effect except 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 absorbent qualities, it served, if speedily applied, to extract the poison from the wound.[3171]
Coecilia.—The rocky jungle, bordering the higher coffee estates, provides a safe retreat for a very singular animal, first introduced to the notice of European naturalists about a century ago by Linnæus, who gave it the name Coecilia glutinosa, to indicate two peculiarities manifest to the ordinary observer—an apparent defect of vision, from the eyes being so small and embedded as to be scarcely distinguishable; and a power of secreting from minute pores in the skin a viscous fluid, resembling that of snails, eels, and some salamanders. Specimens are rare in Europe owing to the readiness with which it decomposes, breaking down into a flaky mass in the spirits in which it is attempted to preserve it.
The creature is about the length and thickness of an ordinary round desk ruler, a little flattened before and rounded behind. It is brownish, with a pale stripe along either side. The skin is furrowed into 350 circular folds, in which are imbedded minute scales. The head is tolerably distinct, with a double row of fine curved teeth for seizing the insects and worms on which it is supposed to live.
Naturalists are most desirous that the habits and metamorphoses of this creature should be carefully ascertained, for great doubts have been entertained as to the position it is entitled to occupy in the chain of creation.
Batrachians.—In the numerous marshes formed by the overflowing of the rivers in the plains of the low country, there are many varieties of frogs, which, both by their colours and by their extraordinary size, are calculated to excite the surprise of a stranger. In the lakes around Colombo and the still water near Trincomalie, there are huge creatures of this family, from six to eight inches in length[3181], of an olive hue, deepening into brown on the back and yellow on the under side. A Kandyan species, recently described, is of much smaller dimensions, but distinguished by its brilliant colouring, a beautiful grass green above and deep orange underneath[3182].
In the shrubberies around my house at Colombo the graceful little tree-frogs[3191] were to be found in great numbers, sheltered under broad leaves to protect them from the scorching sun;—some of them utter a sharp metallic sound at night, similar to that produced by smacking the lips.
In the gardens and grounds toads[3192] crouch in the shade, and pursue the flies and minute coleoptera. In Ceylon, as in Europe, these creatures suffer from the bad renown of injecting a poison into the wound inflicted by their bite.[3193] The main calumny is confuted by the fact that no toad has yet been discovered furnished with any teeth whatsoever; but the obnoxious repute still attaches to the milky exudation sometimes perceptible from glands situated on either side behind the head; nevertheless experiments have shown, that though acrid, the secretions of the toad are incapable of exciting more than a slight erythema on the most delicate skins. The smell is, however, fetid and offensive, and hence toads are less exposed to the attacks of carnivorous animals and of birds than frogs, in which such glands do not exist.
In the class of Reptiles, those only are included in the order of Batrachians which undergo a metamorphosis before attaining maturity; and as they offer the only example amongst Vertebrate animals of this marvellous transformation, they are justly considered as the lowest in the scale, with the exception of fishes, which remain during life in that stage of development which is only the commencement of existence to a frog.