Sublimation
A process by which certain volatile substances are raised by heat and again condensed by cold into a solid or crystallized form, as iodine, sulphur, arsenic. Camphor thus vaporizes and condenses in crystals on the sides of the chemist's jars by the rise and fall of ordinary temperatures. It is possible, by decomposing a compound liquid or gas, to obtain one or more of its constituents crystallized. Various gases when passed through red-hot tubes deposit crystals. Metallic solutions are decomposed by passing a galvanic current through them, the metals being deposited in the crystalline form. See SULPHUR; ARSENIC.