DEPURATION is the freeing of any fluid from its heterogeneous matter or feculence. It is of three kinds. 1. Decantation; which is performed by letting the liquid to be depurated stand for some time in a pretty deep vessel, till the gross sediment has fallen to the bottom; after which the clear fluid is poured off. 2. Despumation; which is performed by means of the whites of eggs, or other viscous matter, and is also called CLARIFICATION. 3. Filtration. See CHEMISTRY, no 69.