164 THE VITAL FUNCTIONS. 



the gastric juice was found to dissolve only animal 

 substances, and to exert no action on vegetable 

 matter; while, on the contrary, that taken from 

 herbivorous animals, acted on grass and other vege- 

 table substances, without producing any effect on 

 flesh ; but in those animals, which, like man, are 

 omnivorous, that is, partake indiscriminately of 

 both species of aliment, it appeared to be fitted 

 equally for the solution of both. So accurate an 

 adaptation of the chemical powers of a solvent to 

 the variety of substances employed as food by dif- 

 ferent animals, displays, in the most striking 

 manner, the vast provision of nature, and the re- 

 fined chemistry she has put in action for the accom- 

 plishment of her different purposes. 



In the stomachs of many animals, as also in the 

 human, it is impossible to distinguish with any 

 accuracy the organization by which the secretion 

 of the gastric juice is effected : but where the struc- 

 ture is more complex, there may be observed a 

 number of glandular bodies interspersed in various 

 parts of the internal coats of the stomach. These, 

 which are termed the Gastric glands, are distributed 

 in various ways in different instances : they are 

 generally found in greatest number, and often in 

 clusters, about the cardiac orifice of the stomach ; 

 and they are frequently intermixed with glands of 

 another kind, which prepare a mucilaginous fluid 

 serving to protect the highly sensible coats of the 

 stomach from injurious impressions. These latter 

 are termed the mucous glands, and they are often 

 constructed so as to pour their contents into inter- 

 mediate cavities, or small sacs, which are denomi- 

 nated yb/Z/c/e^, where the fluid is collected before it 



