[L.] A yellow mineral, occrring in large quantities either as pyrites (sulphides), gypsum (sulphates), or native, mixed with gyp-sum. It is found in volcanic regions. It is purified by distillation, and is obtained by sublimation as a lemon-yellow powder (flowers of sulphur) or as sticks (brimstone). It burns with a blue flame and a peculiar irritating odor. It is used in gunpowder, and in making matches, in medicine, and in making sulphuric acid. Sulphur is also obtained as crystals.-Sulphuric acid, the most important compound of sulphur and oxygen, is a heavy, corrosive oily liquid, colorless when pure, but usually of a brownish color. It is used in the manufacture of hydrochloric and nitric acids, alizarin, soda, and bleaching - powders; in making ether, parchment, and nitro-glycerine, and in etching iron. It was formerly called vitriolic acid, and is popularly called vitriol or oil of vitriol. (See Epsom Salts.)