An instrument for separating the small or particles of substances from the grosser; they are made of various forms and sizes, to suit the article to be sifted. In its most usual form it consists of a hoop, from 2 to 6 inches in depth, forming a flat cylinder, and having its bottom constituted of coarse or fine hair, canvass, muslin, lawn, net-work, or wire, stretched tightly over, according to the use intended.
There is a kind of sieve in extensive use amongst druggists, drysalters, and confectioners, termed a drum-sieve, owing to its form, and is used for sifting very fine powders. It consists of three parts or sections; the top and bottom sections of which are covered with parchment or leather, and fit over and under a sieve of the usual form, which is placed between them. Being thus closed in, the operator is not annoyed by the clouds of powder which would otherwise be produced by the agitation, and the material under operation is thus saved from waste.