CORROSIVE SUBLIMATE, a white solid, melting at 288° C and boiling at 3o3° C. It is sparingly soluble in cold, and more so in hot water, and very soluble in alcohol and ether. Chemically it is mercuric chloride (perchloride of mercury), and it is obtained by the action of chlorine on mercury or calomel (q.v.), by the addition of hydrochloric acid to a hot, strong solution of mercurous nitrate, and, commercially, by heating a mixture of mercuric sulphate and common salt, the mercuric chloride sub liming and being condensed in the form of small rhombic crystals. When treated with hydrochloric acid, it dissolves and forms compounds such as ac cording to the temperature and concentration; it also forms double salts with many chlorides; sal alembroth, is the compound with ammonium chloride. It absorbs ammonia to form which may be distilled without decomposi tion. Various oxychlorides are formed by digesting corrosive sublimate with mercuric oxide. Corrosive sublimate has im portant applications in medicine—as an astringent, stimulant, caustic and antiseptic (see MERCURY).