130 PHYSIOLOGY OF ORGANIC LIFE. 



which supply the waste it sustains in point of 

 quantity also. 



With respect to saliva, instead of considering 

 it as an auxiliary to the teeth, in acting upon 

 the food ; it is, for the most part, viewed as a 

 mere mucous fluid, intended to lubricate the 

 surface of the mouth. The saliva, however, 

 seems destined to a higher office. While the food 

 is broken down, with respect to mass, by the me- 

 chanical action of the teeth, the saliva is intended 

 to assist the teeth in comminuting those parts 

 into smaller particles. It is one of the first 

 agents employed to eliminate the specific and 

 chemical qualities which the food contains ; it 

 bereaves acids of their acidity; alkalies of their 

 acrimony ; and, to a certain and limited extent, 

 blunts the asperity of both; rendering the 

 different articles of food bland and mild, as a 

 preparatory step to the action, in the stomach, 

 which the food is to undergo. 



The various facts which were produced by 

 Mr. HUNTER, and which have been multiplied 

 without end, by others, prove, in a manner the 

 most decisive, that the change which the food 

 undergoes in the stomach, from a dead to a 

 living state, is a living, not a chemical act. Al- 

 though all agree that the gastric juice is the 

 agent, by the energy of which the process is 

 accomplished, with the exception of a few, the 

 effect is referred to a chemical, not to a living 



