DIGESTION. 167 



suture?, and the extremity of the canula left projecting between its 

 edges. The secretion is thus diverted from the intestine, and may be 

 collected as it flows from the canula. The operation has been most 

 frequently performed on the dog, but it has also been done on the 

 rabbit, the ox, the sheep, the goat, the pig, and the goose. The secre- 

 tion has been obtained, from the horse, by opening the duodenum and 

 inserting a canula in the orifice of the pancreatic duct. 



The fistula produced by this means is a temporary one, as the ligature 

 soon cuts its way through the duct, and the canula is displaced ; the 

 communication of the duct with the intestine soon becoming re-estab- 

 lished. In the ox, this happens within six or eight days after the 

 operation ; and in the dog, according to Bernard, within three days. 

 As the pancreas, furthermore, is very sensitive to irritation and its 

 secretion liable to alteration by the inflammatory process, it should be 

 collected for examination within twenty-four hours after the insertion 

 of the canula. 



Physical Properties fmd Composition of the Pancreatic Juice. 

 Pancreatic juice, obtained from the dog in the above manner, during 

 digestion, is a clear, colorless fluid, distinctly alkaline, with a well 

 marked viscid consistency, like fluid white of egg. Owing to the 

 abundance of its albumenoid ingredients, it coagulates completely at 

 the boiling temperature, often solidifying into a jelly-like mass. It also 

 assumes a gelatinous consistency on being cooled down to C., again 

 liquefying when raised to the ordinary temperature. According to 

 Schmidt,* it has the following composition: 



COMPOSITION OF PAXCREATIC JCICE. 



Water 900.76 



Albumenoid substances 90.44 



Sodium chloride 7.35 



Potassium chloride 0.02 



Lime phosphate ........ 0.41 



Mairnesian phosphate ....... 0.12 



Soda, lime, and magnesia, in organic combination . 0.90 



1000.00 



The pancreatic juice resembles a solution of albumen in being coag- 

 ulable by heat, by mineral acids, and by alcohol in excess. It presents, 

 however, the important distinction that its organic matter, after being 

 precipitated by alcohol, is again soluble in water. This substance is, 

 therefore, different in character from ordinary albumen, notwithstand- 

 ing the similarity in some of its reactions. 



A striking peculiarity of this secretion, due to the presence of its 

 albumenoid matter, is its property of emulsioning neutral fats. If a 

 few drops of oil be shaken in a test-tube with fresh pancreatic juice, it 

 is instantaneously broken up into a permanent uniform emulsion ; and 

 if the oil be in slight excess it forms, after a time, an opaque creamy 

 layer upon the surface, the greater part remaining diffused through the 



* Annalen der Chemie und Pharmacia. Heidelberg, 1854, Band xcii., p. 33. 



