DIGESTION. 129 



of potassium is the indican reaction. 1 These bacteria also help form 

 the gases of the intestine by a fermentation of the food. The gases 

 in the intestine are nitrogen, carbonic acid, hydrogen, sulphuretted 

 hydrogen, and carburetted hydrogen. The large intestine is not 

 necessary to life, as the cure of chronic constipation has been accom- 

 plished by resection of the intestine. 



THE RCCES 



The foods that have failed to be absorbed, after having remained 

 about three hours in the small intestine, pass into the large intestine, 

 where they remain for about twelve hours. The quantity and con- 



Fig. 36. Stool. Collective Microscopic Picture. X 350. (Partly 

 after NOTHNAGEL. ) (LENHABTZ. ) 



m, Muscle-fiber, e, Intestinal epithelium, ve, The same, "broken down." 

 c, Clostridium butyricum. h, Yeast, p, Vegetable cells, t, Triple phosphate. 



sistency of that secreted daily by an adult varies within wide marks, 

 depending upon the kind of diet, and the length of time the food- 

 stuffs remain within the intestine. The adult eliminates about 8 

 ounces of moist excrement per diem. From a vegetable diet the 

 faeces are both softer and contain a higher percentage of solids, than 

 from a meat diet; softer because their irritations to the intestinal 

 walls heighten mucous secretion and increase peristalsis, thereby 

 hastening its passage, to the detriment of absorption. In a meat 

 diet the want of this stimulation retards defecation to such an extent 



'Herter, "Chemical Pathology." 



