454 SUCCUS ENTERICUS. [BOOK n. 



is present, the fatty acids thus set free form their corresponding 

 soaps. Pancreatic juice contains fats, and is consequently apt after 

 collection to have its alkalinity reduced ; and an aqueous infusion 

 of a pancreatic gland (which always contains a considerable amount 

 of fat) very speedily becomes acid. 



Thus pancreatic juice is remarkable for the power it possesses 

 of acting on all the food-stuffs, on starch, fats and proteids. 



The action on starch, the action on proteids, and the splitting 

 up of neutral fats appear to be due to the presence of three distinct 

 ferments, and methods have been suggested for isolating them. 

 The emulsifying power, on the other hand, is connected with the 

 general composition of the juice (or of the aqueous infusion of the 

 gland), being probably in large measure dependent on the alkali 

 and the alkali-albumin present. The proteolytic ferment trypsin 

 as ordinarily prepared seems to be proteid in nature and capable 

 of giving rise, by digestion, to peptone ; but it may be doubted, as 

 in the case of pepsin and other ferments, whether the pure ferment 

 has yet been isolated. There are no means of distinguishing the 

 amylolytic ferment of the pancreas from ptyalin. The term pan- 

 creatin has been variously applied to many different preparations 

 from the gland, and its use had perhaps better be avoided. 



The action of pancreatic juice, or of the infusion or extract of 

 the gland, on starch, is seen under all circumstances, whether the 

 animal be fasting or not. The same may probably be said of the 

 action on fats. On proteids the natural juice, when secreted in a 

 normal state, is always active. The glycerin extract or aqueous 

 infusion of the gland, on the contrary, as we have already explained, 

 238, is active in proportion as the trypsinogen has been converted 

 into trypsin. 



Succus Entericus. 



250. When, in a living animal, a portion of the small 

 intestine is ligatured, so that the secretions coming down from 

 above cannot enter its canal, while yet the blood-supply is 

 maintained as usual, a small amount of secretion collects in its 

 interior. This is spoken of as the succus enteric as, and is supposed 

 to be furnished by the glands of Lieberkiihn, of which we shall 

 presently speak. 



Succus entericus may be obtained by the following method, known 

 as that of Thiry modified by Yella. The small intestine is divided in 

 two places at some distance (30 to 50 cm.) apart. By fine sutures the 

 lower end of the upper section is carefully united with the upper end 

 of the lower section, thus as it were cutting out a whole piece of the 

 small intestine from the alimentary tract. In successful cases, union 

 between the cut surfaces takes place, and a shortened but otherwise 

 satisfactory canal is re-established. Of the isolated piece the two 

 ends are separately brought through incisions in the abdominal 



