216 THE PROTEOLYTIC ENZYME. [BOOK II. 



hypothesis as Griitzner believes that the central zones of the 



to the seat of pancreatic cells not only form the proteolytic enzyme 

 formation of of the pancreas, but that the fat-decomposing and 

 thefat-decom- diastatic enzymes are also formed there, 

 posing ferment. 



The part which the emulsionizing and fat-decomposing properties 

 of the pancreatic juice plays in intestinal digestion will be treated of 

 in Chapter VI. 



SECT. 6. THE PROTEOLYTIC ENZYME TRYPSIN. 



Historical notes on the discovery of the property of the Pancreatic 

 Juice to dissolve and digest Proteids. 



The state- It was, we are informed by Corvisart, discovered by 



ments of Purkinji and Pappenheim in 1836 that the pancreas 



Purttnji and can furnish extracts which possess the power of dis- 

 Pappenheim. solving proteids 1 , but the discovery seems to have passed 

 altogether unnoticed 2 . 



Claude Claude Bernard does not appear to have known 



Bernard's the researches of the authors just mentioned. In his 



statements. writings on the pancreas, he, however, stated that the 

 pancreatic juice by itself has no action upon proteids, but that it is 

 able to dissolve them either when they have first of all been subjected 

 to the action of bile or when it acts in conjunction with bile. He 

 pretended, indeed, that by mixing bile and pancreatic juice a liquid 

 is obtained possessed of new properties, being capable not only of 

 emulsionizing and decomposing fats and of converting starch into 

 sugar, but of dissolving proteids 3 . To this function of the pan- 

 creatic juice Claude Bernard, however, attributed but little weight; 

 he, indeed, subordinated in a remarkable degree the other functions 

 of the pancreas to the one which he had himself discovered, viz. 

 its action upon fats. 



Corvisart's The whole merit of clearly pointing out the great 



discoveries 4 . error into which Claude Bernard had fallen in denying 

 a proteolytic action to the pancreatic juice per se, belongs to Lucien 



1 The references given by Corvisart are the following : Burdach, Traite de physio- 

 logic, traduit par Jourdan sur la deuxieme edition, ix e vol. p. 317. Paris, 1841. 

 D'apres Froriep's Notizen, Vol. 14. 



2 This statement is made because of the silence of all the important systematic 

 writers on this matter. 



3 Claude Bernard, Lemons de Physiologic Experimental, Vol. n. (1856), p. 440 et seq. 



4 Corvisart, Sur une fonction pen connue du Pancreas: La Digestion dcs Aliments 

 azotes, Paris, 1857-58. 





