This section is from the book "The Hygienic System: Fasting And Sun Bathing", by Herbert M. Shelton. Also available from Amazon: The Hygienic System Vol III Fasting and Sun Bathing.
The secretions of the body on the whole are either suspended altogether or greatly reduced during the fast. Secretion is commensurate with need. The body is not wasteful of its supplies, as a brief study of secretion will show.
The saliva is greatly diminished. Von Noorden says of Succi's experimental fast: "The secretion of saliva diminished in acute starvation even when water was taken ad libitum. Thus, Succi, on the seventh day of his fast, only produced as much saliva by the movements of his jaws in three hours as under ordinary circumstances is secreted in five minutes." Saliva changes during the fast from its normal alkalinity to a neutral or slightly acid condition. It again becomes alkaline upon the return of hunger or after eating is resumed.
In some cases the saliva becomes very foul and possesses a very unpleasant taste, sometimes, even causing vomiting. In certain cases it may be thick, tough, transparent, gelatinous, slimy and then gray, yellowish, greenish and even pus-like.