298 Medicine. [Chap. i.v\ 



the state of gas should be admitted. In this case 

 it is evident that the air at first would only set free 

 part of its caloric, and that the remainder must 

 gradually escape in the successive stages of the cir- 

 culation. In another mode, likewise, that defect 

 has been attempted to be remedied. It has been 

 alleged, that the evolution of caloric attends almost 

 all chemical combinations; that all animal fluids 

 which pass through capillary vessels and glands, for 

 the purposes of secretion, are subjected to such new 

 chemical combinations, as must incessantly give 

 out heat ; and that this glandular action thu,s ac- 

 counts for the more general and copious source of 

 animal temperature. 



From the view of respiration now given, it re- 

 sults that the final causes of that function are these : 



1. To complete the assimilation of the blood: 



2. To produce and support animal heat : 3. To 

 impart a quality to the circulating fluid which 

 enables it to stimulate the left side of the heart. 



After this account of respiration, vvliich, from 

 its great importance in the animal economy, has 

 been treated of more at large than was at first in- 

 tended, it is proper to proceed to the consideration 

 of Digeslion. This function in its full extent in- 

 cludes all the changes which aliment undergoes for 

 the formation of chyle, whether such changes are 

 elFected in the mouth, stomach, or small intes- 

 tines. But as it is the knowledge of the oflice of 

 the stomach which has received the most impor- 

 tant improvement within the period assigned for 

 this retrospect, and as the other parts of the pro- 

 cess, such as mastication, deglutition, the admix- 

 ture of saliva, &c., were tolerably well understood' 



