Retort
A vessel employed for the purpose of decomposing bodies by the aid of heat, the process being termed distillation. Those used in the chemist's laboratory are a kind of globular bottle, with a long neck bent at an angle of about sixty degrees with the belly of the retort; they are made of glass, porcelain, platinum, earthenware, etc., according to the substances to be acted upon. The spirit-lamp, gas, or sand-bath is usually employed for heating glass retorts, but when higher temperatures are required it is necessary to use those made of platinum or earthenware.
Single retorts for distilling coal-gas are usually made D-shaped, about 21 X 14 inches X 9 feet, closed at one end, and provided with a mouthpiece at the other.
Through retorts are made twice this length, with both ends open, but having mouthpieces which close them during the process of distillation. Formerly these retorts were all made of cast iron, but they are fast being superseded by those made of fire-clay, which admit of higher temperatures and last much longer. The distillation of mercury from cinnabar is conducted in retorts similar to those used for making illuminating-gas. See DISTILLATION; MERCURY; TAR.