MOVEMENTS OF THE INTESTINES 



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either food or saliva, gases developed by the decomposition of foods, or of the 

 secretions and excretions thrown into the intestines. The decomposition of 

 foods is the chief source. The following table, compiled by Brinton, is a col- 

 lection of analyses that have been made and is chiefly valuable as showing 

 the kinds of gases present: 



GASES FOUND IN THE ALIMENTARY CANAL. 



The amounts of the gases vary with the diet. 



An analysis of the intestinal gases (Ruge, copied by Halliburton) in man 

 is as follows: 



The carbon dioxide arises from the carbonates and lactates in food, from 

 fermentation and putrefaction of carbohydrates and proteids, and from 

 butyric-acid fermentation. 



The hydrogen is derived from butyric- and lactic-acid fermentations, and 

 carbureted hydrogen comes from the decomposition of acetates and lactates 

 and from cellulose. The nitrogen is derived from the swallowed air. 



MOVEMENTS OF THE INTESTINES. 



The muscular activity of the intestines accomplishes two important func- 

 tions, i.e., it thoroughly mixes the digesting food and secretions and it carries 

 the content along the tract. Intestinal peristalses have been described for a 

 long time. These peristalses begin as contractions of the circular muscles, 

 producing ring-like constrictions that are propagated as waves over the intestine 



