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FOOD AND DIGESTION 



Intestinal Gases. Under ordinary circumstances, the alimentary 

 canal contains a considerable quantity of gases. The presence of gas in the 

 intestines is so constant and the amount in health so uniform that there can 

 be no doubt that its existence is a normal condition. 



The gas contained in the stomach and bowels is from air swallowed with 

 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, although the amounts of the gases vary with 

 the diet. 



GASES FOUND IN THE ALIMENTARY CANAL. 



An analysis of the intestinal gases by Ruge in man is as follows: 



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 intes- 

 tine from above downward. Such constrictions carry the intestinal contents 

 forward. The longitudinal muscles by their contraction produce pendular 

 motion of the intestine. 



A most instructive contribution to the knowledge of intestinal movements 



