THE PANCREATIC JUICE. 139 



glycerin and the corresponding fatty acids. While this phenomenon 

 has by some been referred to the action of bacteria, others hold that 

 it is dependent upon the presence of a specific ferment, which has 

 been termed steapsin. That the latter view is probably the correct 

 one, appears from the fact that the same result is obtained if the 

 perfectly fresh gland is used and care is taken to prevent the 

 action of micro-organisms by adding a small amount of hydro- 

 cyanic acid or of mercuric chloride. Of the nature of the ferment 

 nothing is known, but it is manifestly very unstable, as extracts 

 prepared from glands that have been left exposed to the air for 

 twenty-four hours are perfectly inert when brought in contact with 

 neutral fats. Apparently it is digested during this time by the 

 trypsin. To demonstrate the action of steapsin on fats, a small 

 amount of perfectly fresh pancreas is finely hashed and dehydrated 

 with 90 per cent, alcohol. It is then dried between filter-paper and 

 placed in an ethereal solution of neutral butyrin (Butterfett). On 

 evaporation of the ether the remaining material is kept between two 

 watch-crystals at a temperature of from 37 to 40 C., when after 

 awhile a distinct odor of butyric acid becomes manifest (Cl. Bernard). 

 Or, a small amount of neutral fat is treated with a few cubic centim- 

 eters of a feebly alkaline glycerin extract of the fresh gland (9 

 parts of glycerin and 1 part of a 1 per cent, solution for each gramme 

 of the gland), to which a few drops of tincture of litmus are added. 

 If this mixture is then kept at a temperature of 37 C., it will be 

 noted that the alkalinity gradually decreases, and the reaction finally 

 becomes acid, owing to the liberation of free fatty acids (Hammar- 

 sten). 



The emulsifying action of the pancreatic juice is owing to the 

 decomposition of the neutral fats and the subsequent saponification 

 of the resulting acids by the alkaline salts which are at the same 

 time present. 



Maltase. The presence of maltase in the pancreatic juice can 

 only be inferred indirectly from the fact that small amounts of 

 glucose are invariably formed during the action of the aqueous 

 or glycerin extract of the gland upon starch. 



Chymosin. Chymosin can be demonstrated by adding a small 

 amount of the pancreatic juice of the ox, pig, or sheep to milk, when 

 coagulation results, as in the case of the chymosin of the gastric 

 juice. The ferment, however, is not present in all mammals; in 

 dogs, for example, it is absent. 



The glucolytic ferment of Lepine has thus far not been isolated 

 either from the pancreatic juice or from the gland itself. 



In conclusion, it is to be noted that in some animals, such as the 

 rabbit, a secretion analogous to that of the pancreas is furnished also 

 by the glands of Brunner, which are found in the upper portion of 

 the duodenum. In other animals, however, such as the dog, the 

 function of these glands is to be compared to that of the pyloric 

 glands of the stomach ; and according to Gri'itzner, extracts of this 



