354: DIGESTION. 



acid. "When a very large quantity of sugar has been taken, 

 a part of it may be converted in the intestine into lactic acid, 

 and this may happen with the sugar which results from the 

 digestion of starch ; but under ordinary conditions, starch 

 and cane-sugar are readily changed into glucose and are ab- 

 sorbed without undergoing further transformation. All the 

 varieties of sugar after they have been absorbed by the por- 

 tal vein and carried to the liver, are here transformed into 

 glucose, the only form under which they can be used in nu- 

 trition. 



Action of the Pancreatic Juice on Nitrogenized Prin- 

 ciples. Although Eberle and some other German observers, 

 particularly Purkinje and Pappenheim, alluded to the action 

 of an acid infusion of the tissue of the pancreas upon certain 

 nitrogenized principles, as early as 1834 and 1836, it is only 

 since the normal pancreatic juice was obtained by Bernard 

 that any thing definite has been ascertained concerning its 

 action upon this class of alimentary substances ; 1 and even 

 now, much remains to be done in this direction. 



"We have frequently had occasion to insist upon the great 

 relative importance of intestinal digestion, and it has been 

 apparent that in the stomach, the process of disintegration of 

 food is not final, even as regards many of the nitrogenized 

 principles, but is rather preparatory to the complete liquefac- 

 tion of these principles, which takes place in the small intes- 

 tine. The experiments, already referred to, of Bernard, in 

 which the pancreas has been partly destroyed in dogs, show 



1 The ideas of the German physiologists concerning the functions of the pan- 

 creas were very indefinite before the publication of Bernard's experiments. The 

 vague and uncertain observations of Eberle and of Purkinje and Pappenheim are 

 simply alluded to in some of their most elaborate works upon physiology (see 

 BURDACH, Traite de Physiologic, trad, par Jourdau, Paris, 1841, tome ix., p. 

 317). These observations by no means justify the claim made by Corvisart that 

 the authors referred to discovered the action of the pancreatic juice upon the 

 albuminoids (CORVISART, Sur-une Fonction pen connue du Pancreas, Paris, 1857 

 -1858, p. 1). 



