FILTRATION

(Lat.) The proce by which liquids are separated from substances mechanically suspended in them; it is also sometimes resorted to to separate colouring matters and other bodies which are in a state of solution, and which are removed by the substance or 451 FINE OF LANDS. matter through which the liquids are filtered. Unsized paper is commonly used in the chemical laboratory for the former purjiose, and is known under the name of filtering paper; it is properly folded, and placed for support in a gla funnel. In the arts, linen and calico bags of different forms are frequently employed, containing well-burned charcoal or other materials, through which the liquids requiring purification are suffered slowly to trickle. In water filters, the coarser particles are generally collected in a piece of sponge, and the further separation of the more finely divided matters or organic taints is effected by layers of sand of various degrees of finene mixed with a proper quantity of charcoal. ( See Faraday's Chemical Manipulation; and Ure's Diet, of Arts, 8(C.) [s. 464]