is that fluid by which the mouth and tongue are continually moistened in their natural state; and is supplied by glands which form it, that are called salivary glands. This humour is thin and pellucid, incapable of being concreted by the fire, almost without taste and smell. By chewing, it is expressed from the glands which separate it from the blood, and is intimately mixed with our food, the digestion of which it greatly promotes. In hungry persons it is acid, and copiously discharged; and in those who have fasted long it is highly acid, penetrating, and resolvent. A too copious evacuation of it produces thirst, loss of appetite, bad digestion, and an atrophy.