Barium, Sulphide of

BaS. Syn. Sul′phide of barium , Sul′phuret of baryta ; Ba′′rii sulphure′tum , ., L.; Sulfure de baryum , ., Fr. Prep. Sulphate of barium, well dried and in fine powder, 3 parts; powdered charcoal or powdered coal, 1 part; the mixture is pre ed tightly into an earthen crucible, and the cover being fitted on, it is exposed for 1 1 ⁄ 2 to 2 hours, to a bright red heat; after it has cooled, the black ma thus obtained is powdered, and boiled in water, and the resulting solution allowed to crystallise. Some authorities recommend forming the mixed powders into a stiff paste with oil, or oil of turpentine, before calcination; but this is not at all nece ary. Prop., Uses, . Crystals, thin and nearly colourle plates, containing combined water; very soluble in hot water, le so in cold water; and rapidly decomposed by exposure to the air. It is principally used to form the BARIUM SALTS , and in organic analysis. Care should be taken in its preparation to expose the solution to the air as little as po ible. Sulphides of a higher grade may be formed by boiling this compound with sulphur; but they po e little practical interest.