160 NON-DIGESTION OF THE STOMACH. [BOOK II. 



The final Products of Digestion which leave the Stomach. The 



Chyme. 



As a result of the combined influence of the gastric juice, of the 

 movements of the stomach, and of the high temperature of the organ, 

 the solid alimentary matters are reduced to a pulpy or semi-fluid 

 condition, and it is in this state that they escape through the 

 pylorus into the duodenum. 



During the digestive process, large quantities of proteids and of 

 albuminoid bodies have been converted into peptones, of which 

 doubtless a part though we have no data on the subject is ab- 

 sorbed by the gastric mucous membrane as soon as formed, whilst 

 a part is held in solution in the liquid portion of the chyme. As a 

 result of the action of the acid of the gastric juice, insoluble mineral 

 salts, as e.g. bone-earth, are dissolved and doubtless are absorbed, 

 as are also soluble salts, sugar, and large quantities of water. 



The chyme then must contain chiefly the undigested or partially 

 digested fragments of food, mixed with gastric juice holding in solu- 

 tion products of digestion. 



Accordingly we observe it to contain fragments of muscle, indi- 

 vidual muscular fibres, splitting into fibrils, but especially tending 

 to cleave into transverse discs. The fibrillar connective tissue has, 

 wholly or in great part, disappeared, but yellow elastic tissue is 

 found apparently quite intact ; the same remark applies to cellulose 

 and to the epidermal tissues of animals. If raw starch has been 

 partaken of, the chyme is sure to contain unaltered starch grains. 



Lastly, if adipose tissue or any fat was contained in the food, 

 drops of liquid fat are found in the chyme. It has been observed by 

 Richet that where the contents of the stomach contain much fat, 

 this appears to be retained in the stomach until all other matters 

 have been expelled. 



SECT. 14. THE NON-DIGESTION OF THE STOMACH BY ITS JUICE. 



The fact that the delicate mucous membrane of the living stomach 

 is not digested by the gastric juice which it secretes early attracted 

 the attention of observers. 



Post-mortem John Hunter 1 was the first to draw attention to the 

 digestion of the fact that when animals or human beings are killed 

 stomach. whilst the digestive process is actively proceeding, it 



not unfrequently happens that large portions of the stomach are 

 softened and perforated. The gastric juice, then escaping, may act 

 upon adjacent organs, partially digesting them, as in a case which 

 came under the notice of the Author, and in which a part of the 



1 John Hunter ' Observations on Certain Parts of the Animal Economy,' London, 

 1786, and Philosophical Transactions for 1772. 





