Studies of saliva in its relation to the teeth

By the use of a slight modification of the Folin-Benedict method for the determination of uric acid in blood, we definitely established the presence of uric acid (urate) in saliva. The average quantity of uric acid in saliva from men amounted to 2.10 mg. per 100 c.c. of the secretion; in saliva from women it amounted to I. I I mg. per 100 C.C. We also succeeded in separating uric acid, in crystalline form, from saliva. For normal individuals, the proportion of uric acid in saliva was independent of the diet, speaking generally, but was influenced by the rate of secretion as well as by the nature of the stimulant employed to accelerate the flow of the saliva. Saliva appears to register promptly the variations in the endogenous metabolism of uric acid. We noted an almost immediate rise in the proportion of uric acid in saliva after increased muscular exertion, and after the ingestion of purine-free food following a brief fast. We also observed a definite relationship between the quantity of uric acid excreted in saliva, and the quantity eliminated simultaneously in the urine, in normal people on an ordinary diet. The details of this study, and those related to it, will be published in the Journal of Dental Research.