180 



THE VITAL FUNCTIONS. 



pylorus appears to be one means employed for 

 attaining this end ; and another is derived from 

 the property which the gastric juice possesses of 

 coagulating, or rendering solid, every animal or 

 vegetable fluid susceptible of undergoing that 

 change. This is the case with fluid albumen ; 

 the white of an egg, for instance, which is 

 nearly pure albumen, is very speedily coagu- 

 lated when taken into the stomach ; the same 

 change occurs in milk, which is immediately 

 curdled by the juices that are there secreted, 

 and these effects take place quite independently 

 of any acid that may be present. The object 

 of this change from fluid to solid appears to be 

 to detain the food for some time in the stomach, 

 and thus to allow of its being thoroughly acted 

 upon by the digestive powers of that organ. 

 Those fluids which pass quickly through the 

 stomach, and thereby escape its chemical action, 

 however much they may be in themselves 

 nutritious, are very imperfectly digested, and 

 consequently aflbrd very little nourishment. This 

 is the case with oils, with jelly, and with all 

 food that is much diluted.* Hunter ascer- 



I 



* A diet consisting of too large a proportion of liquids, 

 although it may contain much nutritive matter, yet if it be 

 incapable of being coagulated by the stomach, will not be 

 sufficiently acted upon by that organ to be properly digested, 

 and will not only aftord comparatively little nourishment, but 

 be very liable to produce disorder of the alimentary canal. Thus 



