DIGESTION. 83 



strong compound weak. The substance of young animals con- 

 sists generally of weaker compounds than that of old, and is 

 therefore tenderer and easier of digestion. Besides this reduction 

 to a weaker state, the articles of food in general are more or less 

 dissolved in the stomach. 



After the solution of the food and the reduction of its proxi- 

 mate principles to the weaker forms, the stomach possesses the 

 power of conversion, or of changing the proximate principles of 

 the food into others, so that a fluid, called chyle, of pretty uniform 

 composition, is obtained from it. Thus, it would appear, that the 

 various substances belonging to the classes of saccharine, albu- 

 minous, and oleaginous, are all convertible into each other, some 

 out of the body, some only within it. The albuminous and olea- 

 ginous require little change; and although the saccharine must 

 require more, we ought to remember that sugar spontaneously 

 becomes alcohol out of the body, and that alcohol is merely an 

 oleaginous substance of a weak kind, and therefore probably un- 

 dergoes in the stomach a similar series of changes to those which, 

 out of the body, convert it to alcohol. y 



The cardiac portion of the stomach is the chief seat of di- 

 gestion, and when a part of the food is tolerably digested it passes 

 along the large curvature to the pyloric portion, where the pro- 

 cess is completed. As the cardiac half is the great digesting 

 portion, it is this half that is found sometimes to have been dis- 

 solved by the gastric juice after death; its contents are much 

 more fluid than those of the pyloric half; and Dr. Philip, who by 

 the dissection of about a hundred and thirty rabbits has been 

 enabled to furnish the completest account of what goes on in the 

 stomach, relates the case of a woman who had eaten and properly 

 digested to the last, but whose stomach was ulcerated every 

 where except at the cardiac end. Sir Everard Home says he 

 found that fluids which had been drunk were chiefly contained in 

 the cardiac portion, and, like many others, for upwards of a cen- 

 tury and a half 2 , that, if the body was examined early after death, 

 the two portions of the stomach were frequently in fact divided 

 by a muscular contractions Dr. Haighton observed the same 



y Dr. Prout, 1. c. p. 498. sqq. 



z See Dr. Monro (Tertius), Outli?ies of the Anatomy of the. Human Body in its 

 sound and diseased State, vol. ii. p. 111. 1813. 

 a Phil. Trans. 1808. 



G 4 



