ACTION OP THE PANCREATIC JUICE IN DIGESTION. 341 



when neutralized with an acid, there is a considerable evo- 

 lution of carbonic acid ; which does not occur in fresh pan- 

 creatic juice. 



A reaction peculiar to decomposed pancreatic juice is 

 described by Bernard. On the addition of a small quantity 

 of chlorine-water, a red color is produced which disappears 

 in an excess of the reagent. 1 The color is intense in propor- 

 tion to the extent to which decomposition of the organic 

 matter has advanced ; except, however, when the process of 

 putrefaction has arrived at its last degree, when the exces- 

 sive alkalinity interferes with the reaction, and the color 

 only appears when the fluid has been neutralized with an 

 acid. 2 



Action of the Pancreatic Juice in Digestion. 



It is only since the observations of Bernard, in 184:8, that 

 the pancreatic juice has been regarded as a fluid of any great 

 importance in digestion. It has now been demonstrated, 

 both by cases of disorganization of the pancreas in man, and 

 by experiments on animals, in which the tissue of the organ 

 has been destroyed, that the pancreatic juice is essential to 

 digestion and to life ; animals dying of inanition when its 

 function has been abolished. 



The most striking feature in the discovery made by Ber- 

 nard was the action of the pancreatic juice in the digestion 

 of fats ; it being shown that these principles are acted upon 

 almost exclusively by the pancreas, and that they pass 

 through the alimentary canal undigested when this organ 

 has been destroyed. For this reason, probably, the action of 

 -the pancreas in the digestion of fatty substances has received 



1 BERNARD, op.,cit., p. 57. 



2 This reaction with chlorine was observed by Tiedemaun and Gmelin (Re- 

 cherches Experimental, etc., Paris, 1827, tome L, p. 41); but these authors re- 

 garded it as one of the properties of the normal secretion. Bernard does not 

 assume to have been the first to observe the peculiar color produced by chlo- 

 rine, but simply to have pointed out the fact that it occurs in the decomposed, 

 and not in the normal secretion. 



