RETORT, a vessel employed by chemists for the purpose of distilling or effecting decomposition by the aid of heat. It may be made of glass, earthenware, or metal, according to the purposes for which is to be employed.
Glass retorts are the most common, and their ordinary form is seen in the figure. They may he employed for the production of such products as do not require any extra ordinary degree of cold for the condensation of their vapor—as, for instance. for the production of hydrocyanic or nitric acid. The globular vessel in which the neck of the retort is inserted is from its function termed the receiver. Cold may be applied to the neck of the retort—for the purpose of condensing the vapor—in various ways. as by the application of a cold wet cloth, by a current of water,' or by a special apparatus known as Licbt:V.4 condenser.
- In the accompanying figure a Lithig condenser is fitted on to the retort. A is the bulb of the retort, into which the matter to be distilled is inserted. It Can be opened or closed at will at the top by a ground-glass stopper. From the bulb the neck proceeds, and its termination is seen in the receiver D. The condenser, BI3, embraces
the greater part of the neck of the retort. It consists of a glass tube, tapering from end to end, fixed in the Center of a metal pipe, pro vided with tubes, so arranged that u current of cold water may circu late through the apparatus. By putting a Jew pieces of ice into the little cistern, E, the temperature of this water may be kept at 32°, and extremely volatile liquids con densed.
'1'1,0 retort may be heated in various ways—as by means of a lamp, or by placing its body in a mnd-hntit nr even in the fire• in _ _ the last case, the retort is usually protected by a coaling of lute.
In ordinary eases requiring a higher temperature than glass could bear, earthen retorts are used; for the preparation of hydrofluoric acid, retorts of lead are employed; while for the preparation of strong sulphuric acid, platinum is the best material for the retort. Iron retorts are employed in the laboratory for the preparation of oxygen from black oxide of manganese and some other processes; and in gas-works, for the destruc tive distillation of coal.