Still

Still is an apparatus for Distillation (q.v.). It consists essentially of a vessel in which the liquid to be distilled is placed, the vapour being conducted by means of a head or neck to the condenser or worm, where it is cooled by water or other means, and again forms liquid. The still itself varies greatly according to the purpose for which it is used. It is made of copper, iron, earthenware, or glass, and is heated by naked flame or steam-heat. The steam may either be applied on the outside by means of a jacket or inside by the use of a coil. A vacuum still is one in which a partial vacuum is constantly maintained by means of an air-pump, distillation under such circumstances being more rapid and at a lower temperature. See also RETORT.