since one of its processes has been omitted. The only portion of the operation of digestion that can be voluntarily controlled is that which is done in the mouth, hence the subject of the mastication of food is an all-important one. Its value in the economy of the human body is excellently treated by Horace Fletcher in his "A-B-Z of our own Nutrition."
Fletcher says: "When food is filtered into the body after having become liquified and made alkaline or at least neutral by saliva, the appetite is given a chance to measure the needs of the body and to discriminate against excess. As soon as the point of complete saturation of any one deficiency is reached, the appetite is cut off as short as possible, with no indication of stomach fullness. It will welcome a little of protein, and then turn to sugar or fat in some of their numerous forms. Thirst for water will assert itself for a moment, sometimes asking but a drop and again for a full glass ; and, afterwards, when near the point of complete saturation, appetite will hesitate for a moment, as if searching around for some rare substance and may find its final satisfaction in a single spoonful of sweet, or of a sip of something in sight.
