ACTION UPON FATS. 34:7 



moistened filter like milk. This does not take place in the 

 imperfect emulsion formed by a mixture of oil with any 

 other of the digestive fluids. 



Although the normal pancreatic juice is constantly al- 

 kaline, this is not an indispensable condition as regards its 

 peculiar action upon fats ; for the emulsion is none the less 

 complete when- the fluid has been previously neutralized 

 with gastric juice. 



Bernard has shown that the pancreatic juice and the tis- 

 sue of the pancreas have the property of saponifying fats, or 

 decomposing them into a fatty acid and glycerine, and that 

 this property is not possessed by any other tissue or liquid 

 of the economy. 1 The question naturally arises, then, whether 

 this be an accidental property of the tissue and the secretion 

 of the pancreas, or whether partial saponification of fat takes 

 place in digestion. Concerning this point there is no dif- 

 ference of opinion among physiological chemists. The fat 

 which is contained in the lacteal vessels is always neutral ; 

 and the absence of any fatty acid has been recognized by 

 Bernard, as well as by others. The inevitable conclusion to 

 be drawn from this fact is, that while fat may be in part de- 

 composed into an acid and glycerine by the pancreatic juice, 

 out of the body, in the natural process of digestion, either 

 this does not take place, or the acid is not absorbed by the 

 lacteals. The greatest part, if not the whole, of the fat 

 which is digested in the small intestine is simply formed 

 into an emulsion by the pancreatic juice, and undergoes no 

 chemical alteration. 



To complete the experimental evidence of the action of 

 the pancreatic juice in the digestion of fats, Bernard at- 

 tempted to extirpate or destroy the pancreas in a living ani- 

 mal. This he found very difficult. All attempts to extir- 

 pate the organ with the knife being unsuccessful, the injec- 

 tion of foreign matters into the duct was resorted to. After 

 a great number of unsuccessful experiments, in two in- 



1 BERNARD, op. dl., p. 94 et seq. 



