Prep. By passing chlorine gas over hydrate of lime loosely spread out in a proper chamber or vessel until it is completely saturated.

Prop. & Comp. A whitish powder, having the odour of chlorine and an acrid taste; absorbs carbonic acid and water when exposed to the air, and at the same time gives off chlorine; it is only partly soluble in water, the solution being alkaline, and possessing bleaching properties; the addition of oxalic acid causes the rapid and copious evolution of chlorine, and the deposition of oxalate of lime. Composition, probably (Ca O, Cl O), or a hypochlorite of lime; but besides this compound, free lime, chloride of calcium, etc, are present. Ten grains mixed with 30 grains of iodide of potassium, and dissolved in 4 fluid ounces of water, produce, when acidulated with 2 fluid drachms of hydrochloric acid, a reddish solution requiring for the discharge of its colour at least 85 measures of the volumetric solution of hyposulphite of soda, which corresponds to about 11 grains of iodine, or a little more than 3 grains of chlorine.

Off. Prep. Liquor Calcts Chloratae. Solution of Chlorinated Lime. (Not officinal in U. S. P.) (Chlorinated lime, one pound; distilled water, one hundred and sixty fluid ounces.) Sp. gr. 1.035.

One fluid drachm mixed with twenty grains of iodide of potassium dissolved in four fluid ounces of water, when acidulated with two fluid drachms of hydrochloric acid, gives a red solution requiring for the discharge of its colour forty-six measures of the volumetric solution of hyposulphite of soda, equivalent to 1.62 grains of chlorine.

Use. In the preparation of chloroform; also as a disinfectant agent to evolve chlorine: is not often given internally, or used externally, chlorinated or chlorated soda being usually substituted for it.