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284 be confined to a part, by means of a ligature, then permanganate of potash, in a five per cent solution, is an efficient destroyer of its power. Ammonia is not a remedy. Some seeming cures may be accounted for by the fact that, if an insufficient dose of the venom be administered, the bitten animal will live, whether stimulants—alcohol or ammonia—be given or not. The intellect does not appear to be affected by snake poisoning, but remains unclouded to the last.

Turquoises.—The turquoise, in the middle ages, was accredited with even more supernatural virtues than were ascribed to other precious stones. The wearer of it had his sight strengthened and his spirits cheered; if he fell, the gem would break instead of his bones, and save them; and, if he became sick, it turned pale. When its possessor died, it lost its color, to recover it again on passing into the hands of another. In some mysterious way, when suspended by a string, it was capable of correctly striking the hours on the inside of a glass vessel. Turquoise—a hydrated phosphate of alumina colored by traces of compounds of copper and iron—may be of various colors of blue and green, but only the fast sky-blue specimens are prized as precious stones. The other shades may be imitated in inferior stones, this one not. The material of some fossil teeth is capable of being colored with phosphate of iron so as to resemble real turquoise, when it is called odontolite or Occidental turquoise, but it is softer than the genuine Oriental stone, and thereby easily distinguishable from it. Jewelers' turquoises come from the mountains of Khorassan in Persia. A very satisfactory report upon the mines has been furnished the British Foreign Office by Mr. A. H. Schindler, who was for a short time director of them. The veins occur in the met amorphic strata, with which the nummulitic limestone of the mountains is mottled, and are very ancient and extensive, bearing frequent evidences of the old workings. The mines are quite deep, one of them reaching down to one hundred and sixty feet. The works are carried on by the people of the villages, who are careless in management, and improvident. At the mines, the turquoises are roughly divided into three classes, of first, second, and third qualities. All the stones of good and fast color and favorable shape belong to the first class. But they vary most curiously in value, for Mr. Schindler says, "it is impossible to fix any price, or classify them according to different qualities. I have not yet seen two stones alike. A stone two thirds of an inch in length, two fifths of an inch in width, and about half an inch in thickness, cut peikâni (conical) shape, was valued at Meshed at three hundred pounds; another, of about the same size, shape, and cut, was valued at only eighty pounds. The color most prized is the deep blue of the sky. A small speck of lighter color, which only connoisseurs can distinguish, or an almost unappreciable tinge of green, decreases the value considerably. Then there is that undefinable property of a good turquoise, the zât, something like the 'water' of a diamond or the luster of a pearl; a fine colored turquoise without the zât is not worth much." The stones are cut in three ways—the flat or slightly convex form, the truncated cone, and the tallow-drop or en cabochon. The higher the conical and convex surfaces in the two latter, the more the turquoises are prized. None but a fine, deep-colored stone can be advantageously cut into a conical shape, since one of a pale color would appear almost white at the apex. Some mines contain stones which look well at first, but soon change their color and fade. These, of course, are worthless.

Poisons formed from Food.—The subject of "Poisons formed from Food, and their Relation to Biliousness and Diarrhœa," has been considered by Dr. T. Lauder Brunton in articles in "The Practitioner." There are persons, he says, or even, perhaps, "classes of people," to whom even articles of food, usually salutary, are poisonous. Many articles of food, also, have a property of splitting themselves up so as to yield poisons. The melon and cucumber tribe of vegetables exhibits a tendency to the formation of purgative substances. In animal foods poisonous properties are apt to appear either from particular modes of cooking, or from beginning decomposition. The