In this paper it is the intention to allude to some well-known physiologic principles and to describe certain details not so well recognized, all with reference to their application in digestive practice. It is obvious that such a consideration, to be even fairly brief, must be disjointed and incomplete.
1. The Mouth and Salivary Glands.
—The importance of mastication and insalivation is an old story. While admitting it, I am skeptical as to the chemical value of salivary digestion. While, by very elaborate mastication of dry cereals, J. H. Kellogg has been able to accomplish the conversion of considerable quantities of starch into sugar, as ordinarily carried out, even by careful eaters, only the small proportion of soluble starch of the very light test-meal is digested. Some animals are quite lacking in ptyalin, and I believe the principal function of the mouth and salivary glands to be mechanical. It may