Saliva, a term applied to the fluid, with which the mouth and continually moistened: it is secreted by the salival glands.
This humour is thin and transparent; it cannot be reduced to a concrete form by fire, and is almost totally divested both of taste and smell. It is supplied from the glands by mastication ; and, being intimately blended with the aliment, essentially contributes to its digestion ; serving also to improve the taste of food ; to mix with, dissolve, decompose the nutritive matter into its principles; and to moderate thirst.
The saliva of hungry persons, and of such as indulge in violent passion, is extremely acrid, penetrating, and profusely discharged. But, if this fluid be evacuated too copiously, for instance, by those who indulge in smoking tobacco, it excites thirst, and occasions loss of appetite, indigestion, and at length atrophy, with all its attendant evils. On the other hand, if it be swallowed, together with the oil deposited on the tongue from the fumes of that narcotic herb, its effects are alike pernicious. Nor is it advisable to absorb the saliva in sick-rooms, or places where malignant disorders prevail; because the contagious miasma might thus be introduced into the body, as well as by actual contact. - See also Contagion, and Infection.