134 THE VITAL FUNCTIONS. 



vessels, produced, if kept at the usual temperature of the 

 animal, changes, to all appearance, exactly similar to those 

 which take place in natural digestion.* In animals which 

 feed on flesh, the gastric juice was found to dissolve only 

 animal substances, and to exert no action on vegetable mat- 

 ter; while, on the contrary, that taken from herbivorous ani- 

 mals, acted on grass and other vegetable substances, without 

 producing any eflect 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 diflcrent animals, displays, in the most 

 striking manner, the vast resources of nature, and the re- 

 fined chemistry she has put in action for the accomplishment 

 of her difierent purposes. 



In the stomachs of many animals, as also in the human, it 

 is impossible to distinguish with any accuracy the organi- 

 zation by which the secretion of the gastric juice is effected: 

 but where the structure is more complex, there may be ob- 

 served a number of glandular bodies interspersed in various 

 parts of tlic 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 ori- 

 fice 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 



* The accuracy of this conclusion has been lately contested by M. Ue 

 Montcgrc, whose report of the effects of the gastric juice of animals out of 

 the body, docs not accord with that of Spallanzani; but the difference of cir- 

 cumstances in which liis experiments were made, is quite sufficient to ac- 

 count for the discrepancy in the results; and those of M. De Montcgre, there- 

 fore, by no means, invalidate the general facts stated in the text, which have 

 been estabhslicd by the experiments, not only of Spallanzani, but also of 

 Reaumur, Stevens, Leuret, and Lassaigne. See Alison's Outlines of Phy- 

 siology and Pathology, p. 170. 



