CHEWING, or mastication, is the action of the teeth, by which solid food is broken, and divided into smaller particles: thus, being at the same time mixed with the saliva, it is better prepared for digestion, both on account of its pulpy state, and the solvent nature of the fluids, secreted by the salival glands, during the exertion of the adjacent muscles. Hence it is obvious, that those persons, who are in the habit of swallowing their meals with expedition, and afterwards inundate the stomach with large potations, do themselves a double injury: 1. Because their food passes through the stomach, only half digested—affording but a scanty supply of real nourishment; and 2. Their saliva is, against the order of Nature, constantly determined to other emunctories, so that it will, sooner or later, produce cutaneous, and painful diseases.

Chewing-Ball for horses, a kind of medicated bolus, for restoring a proper appetite: it is prepared of asaifœtida, liver of antimony, bay, or juniper-wood, and the pellitory of Spain; which, after being dried in the sun, and wrapped in a strong linen cloth, are fastened to the bit of the bridle, in order to induce the animal to chew the bag. Such balls, it is said, may also be made of Venice treacle, and successfully used for the same purpose. See Ball, p. 152, Horse-balls.