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PHYSIOLOGY OP THE DOMESTIC ANIMALS. 



Heidenhain has employed a method of establishing permanent pancreatic 

 fistulas which he claims to have yielded in his hands satisfactory results. He 

 excises that portion of the duodenum which contains the opening of the pan- 

 creatic duct, restores the continuity of the gut, and sews the excised portion, after 

 division lengthwise, to the abdominal wound, so that the orifice of the duct opens 

 externally upon the abdominal surface. 



1. The Chemical Composition of Pancreatic Juice. — The pancreatic 

 secretion differs in composition and physical properties according as it is 

 obtained from permanent or temporary fistula, and according to the ani- 

 mal from which it is obtained. When obtained from temporary fistulse 

 in the dog, it is a clear fluid, almost of the consistency of syrup, very 



Fig. 160.— Panckeatic Fistula in the Ox. (Colin.) 



tenacious, and of strongly alkaline reaction. It contains few or no struc- 

 tural elements, though corpuscles similar to those found in saliva have 

 been claimed by Ku'hne to exist, and occasionally free particles of oil. It 

 has a decided salty taste, and under the action of heat coagulates, as does 

 the white of egg, to a firm white mass. Alkalies prevent the coagulation. 

 When alcohol is added to the fresh pancreatic secretion it forms a copi- 

 ous, white, flocculent precipitate, which is subsequently in large part, 

 after filtration, soluble in water. When very dilute acids are added to 

 pancreatic juice, they at first form a turbid mass which subsequently 

 dissolves in excess of acid. This action is to be explained as due to the 



