This process consists in boiling a liquid and condensing the vapor which is formed. The liquid, which we may suppose to be water, is heated in a vessel. The steam or vapor, as soon as it is formed, is made to pass through a coil of pipes, placed in a vessel of cold water.

While passing through this soil, the vapor parts with its heat to the cold water, and o n con-d ens i n g is drawn from the end of the worm. The vessel must be constantly replenished with cold water, and the heated water allowed to run off, otherwise the condensation would soon cease. The object of distillation is generally to free the liquid from any impurities it may contain, and also to separate a more volatile liquid from one less so, such as alcohol from water.