Glauber's-Salt, a chemical composition, which is usually prepared by adding to sea-salt an equal quantity or oil of vitriol diluted with water, distilling off the marine acid, and dissolving and crystallizing the remainder.

These salts may also be obtained by mixing four ounces of borax with one ounce and one dram of oil of vitriol; the whole of which, when sublimed, affords what is by chemists called Sedative Salt ; and if the remainder be exposed to a strong fire, it will yield Glauber's-salts. They were first prepared by John RhodolPhus Glauber, a celebrated chemist of the 17th century ; and are of considerable use in medicine as cooling purgatives, when taken in doses from six to twelve'drams : they also prove excellent aperients in various chronical disorders, such as habitual cos-tiveness, for which small doses of one dram of this salt, with two scruples of cream of tartar, and one scruple of sal-ammoniac dissolved in water, may be given with advantage, three or four times a day.