CHLORAL. A liquid, obtained by the action of chlorine as upon alcohol. CHLORATE OF POTASH. A salt composed of chloric acid and potass. It is formed by passing chlorine gas through a solution of caustic potass till no more gas is absorbed, evaporating the liquor and crystallizing. By the action of the gas two salts are formed : a chloride of potassium and a chlorate of potass,—the former remains in solution, the latter crystallizes readily, and it may he separ ated thus from the chloride. Washing and recrystallization are necessary to ob Min a pure salt. Mr. Culvert's improved process consists in forming a mixture of 51 ounces of burnt lime for 1 equivalent of caustic potash, and passing a current of chlorine through the hot murture. In this way chloride of calcium and chlorate of potash are formed. The loss of potash is thus avoided. Chlorate of potash cry stallizes in flat, pearly-looking plates, and has an unpleasant cool taste ; it does not bleach. It dissolves in six parts of cold
water, and when heated to redness, gives out 39 per cent. of oxygen ; it' rubbed hardly in a mortar, it crackles and gives off sparks. When rubbed with sulphur and phosphorus, it detonates danger ously. A mixture of this salt with sugar and sulphuret of antimony, is used for tipping lucifer matches, as it explodes when rubbed on emery or sand-paper. It formed the detonating powder which was dropped in percussion caps ; but owing to the rusting property of the gases pro duced by explosion, fulminate of mercury is now preferred.
Owing to its property of giving off oxy gen readily when decomposed, it has been used to some extent in bleaching fats and oils. It contains 76 parts of chloric acid, and 48 of potassa, in 124 parts of the chlorate.