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THE POPULAR SCIENCE MONTHLY. 



be confined to a part, by means of a liga- 

 ture, 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 ani- 

 mal will live, whether stimulants alcohol 

 or ammonia be given or not. The intel- 

 lect does not appear to be affected by snake- 

 poisoning, but remains unclouded to the 

 last. 



Turquoises. The turquoise, in the mid- 

 dle 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 com- 

 pounds of copper and iron may be of va- 

 rious colors of blue and green, but only the 

 fast sky-blue specimens are prized as pre- 

 cious 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 mount- 

 ains of Khorassan in Persia. A very sat- 

 isfactory 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 num- 

 mulitic limestone of the mountains is mot- 

 tled, and are very ancient and extensive, 

 bearing frequent evidences of the old work- 

 ings. 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 im- 

 possible 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 peikani (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, de- 

 creases the value considerably. Then there 

 is that undefinable property of a good tur- 

 quoise, the zdt, something like the ' water ' 

 of a diamond or the luster of a pearl ; a fine 

 colored turquoise without the zdt 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 con- 

 vex 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 Diarrhoea," has 

 been considered by Dr. T. Lauder Brunton 

 in articles in " The Practitioner." There 

 are persons, he says, or even, perhaps, 

 11 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 for- 

 mation of purgative substances. In animal 

 foods poisonous properties are apt to appear 

 either from particular modes of cooking, or 

 from beginning decomposition. The decom- 



