VARIATIONS AND FUNCTIONS OF BILE. 191 



been established for the examination of the gastric juice. (Fig. 53.) 

 An incision was made through the abdominal walls, a short distance 

 to the right of the median line, the floating portion of the duodenum 

 drawn up toward the external wound, opened by a longitudinal in- 

 cision, and a silver tube, armed at each end with a narrow projecting 

 collar or flange, inserted into it by one extremity, five and a half 

 inches below the pylorus, and two and a half inches below the 

 orifice of the lower pancreatic duct. The other extremity of the 

 tube was left projecting from the external opening in the abdominal 

 parietes, the parts secured by sutures, and the wound allowed to 

 heal. After cicatrization was complete, and the animal had entirely 

 recovered his healthy condition and appetite, the intestinal fluids 

 were drawn off at various intervals after feeding, and their contents 

 examined. This operation, which is rather more difficult than that 

 of making a permanent gastric fistula, is nevertheless exceedingly 

 useful when it succeeds, since it enables us to study, not only the 

 time and rate of the biliary discharge, but also, as mentioned in a 

 previous chapter (Chap. VI.), many other extremely interesting 

 matters connected with intestinal digestion. 



In order to ascertain the absolute quantity of bile discharged 

 into the intestine, and its variations during digestion, the duodenal 

 fluids were drawn off, for fifteen minutes at a time, at various 

 periods after feeding, collected, weighed, and examined separately, 

 as follows : each separate quantity was evaporated to dryness, its 

 dry residue extracted with absolute alcohol, the alcoholic solution 

 precipitated with ether, and the ether-precipitate, regarded as repre- 

 senting the amount of biliary matters present, dried, weighed, and 

 then treated with Pettenkofer's test, in order to determine, as nearly 

 as possible, their degree of purity or admixture. The result of 

 these experiments is given in the following table. At the eigh- 

 teenth hour so small a quantity of fluid was obtained that the 

 amount of its biliary ingredients was not ascertained. It reacted 

 perfectly, however, with Pettenkofer's test, showing that bile was 

 really present. 



