MORTAR, a chemical utensil, used for the division of bodies, partly by percussion and partly by grinding. Mortars have usually the form of an inverted bell, and are made either of iron, stone, stoneware, or glass, &c., according to the use to which they are applied. For the finer chemical processes they are often composed of agate, flint, or porphyry. The matter intended to be pounded is put into them, and then struck and bruised by an instrument denominated a pestle.