248 DIGESTIVE SYSTEM. 



animal's weight : this would give for man, whose mean weight 

 is sixty-five kilogrammes, only 6500 grammes of gastric j uice 

 (in twenty-four hours). 



The most moderate estimate thus places the weight of this 

 juice at one-tenth of that of the body of the animal during 

 the period of twenty-four hours. The case has even been 

 cited of a woman, having a gastric fistula, and was nursing, 

 who yet at the same time produced a quantity of gastric 

 juice equal in weight to one quarter of that of her body 

 (Bechamp). 



B. Small intestine. 



Intestinal Secretions and Digestion. We are already 

 acquainted with the epithelium of the intestinal tube, 

 properly so called, its villosities and its glands (p. 191). 

 We will study the villosities more completely when we 

 come to the subject of absorption. What we have to do 

 now is to seek to discover the nature of the fluids which 

 flow from the glands, and which come more or less in contact 

 with the product of the digestion of the stomach. 



The contents of the stomach enter the intestine in waves, 

 and pass very quickly through the first part of the tube ; this 

 tube has been called the jejunum, because it is generally 

 found empty, the contents of the intestine accumulating in 

 the lower part of the small intestine (ilewn). It has been 

 generally supposed that the secreted products of the differ- 

 ent glands were poured into the intestine at this moment, 

 and thus came in contact with the alimentary substances. 

 This is the case with regard to the product of the glands of 

 Lieberkuhn, and that of the pancreas, but not of the bile. 

 Study of biliary fistulas proves that the bile is poured into 

 the intestine long after the passage of the product of the 

 stomach. The secretion of the bile is connected with absorp- 

 tion, not digestion, and we will study it under that head. 



The fluid secreted by the glands of Lieberkuhn constitutes 

 the enteric juice: this juice is very difficult to collect, and, 

 on this account, the ideas entertained respecting it were 

 erroneous, or, at least, extremely hypothetical : Thiry's pro- 

 cess of procuring it, which is now employed, consists in 

 isolating a certain length of the intestinal tube by two sec- 

 tions ; and joining the tube together again, so that the fluids 

 may flow as before ; one extremity of the part which has 

 been detached, and which adheres only by its mesentery, is 

 then sewed up, so as to form a pocket or cul-de-sac, while 



