122 THE WORK OF THE DIGESTIVE GLANDS. 



india-rubber tube was opened and the contents of the stomach emptied 

 out. For the most part it contained only 15 c.c. to 20 c.c. of oil, and 

 3 c.c. to 5 c.c. of alkaline mucus, while later only mucus mixed 

 with small quantities of oil flowed out. In other cases, together 

 with this mucus, either early or late, some bile or bile-stained fluid 

 escaped from the stomach. This latter fluid contained suspended 

 fat, reacted alkaline, and was obviously driven into the stomach by 

 anti-peristaltic action. Nevertheless, during the whole of this time 

 pancreatic juice freely flowed from the fistula. These facts exclude the 

 immediate idea that an acid reaction is rapidly set up in the intestine by 

 cleavage of the fat, and then acts as an exciter of the pancreas. The in- 

 testinal contents, in the course of an hour or still longer, showed no trace 

 of acid reaction. The experiment affords us adequate grounds for con- 

 cluding that fat is an independent exciter of the pancreatic gland. The 

 investigations of Dr. Walther go still farther, and show undoubtedly 

 that fat excites not only a free secretion of pancreatic fluid, but 

 also leads to an increase of the fat-splitting ferment. In the 

 first two hours after a meal of milk a juice is furnished which is un- 

 commonly rich in fat-splitting ferment. If the milk, however, be 

 deprived of its fat by filtration, the juice presents a very low fat- 

 splitting power, without any other alteration in the progress or rate 

 of the secretion. When, however, the milk filtrate is again mixed with 

 fat that is to say, when the milk is synthetically reconstructed the 

 fat ferment in the pancreatic juice increases to the previous amount, 

 which is characteristic of "milk juice." 



And now, as regards the seat of influence of the fat. We might 

 suppose, from the experiments related, that the stimulus acts on the 

 mucous membrane of the duodenum. Thus we have often observed 

 a strong and lasting secretion of pancreatic juice, even when the 

 stomach had been perfectly emptied of fat. But the mechanism of 

 pancreatic excitation by means of fat scarcely requires a special dis- 

 cussion. When it is borne in mind that fat is a chemically indifferent 

 substance, an effect through the blood can scarcely be thought of. But 

 the fat may well excite the peripheral end-apparatus of the nerves 

 which are specially adapted to react to every possible influence, such as 

 chemical, mechanical, and the like. 



I now wish to introduce some i-emarks relative to the experiments 

 with the oil described above. An emulsion-like fluid, as has been 

 stated, flows for one to two hours from the stomach. This fact, possibly, 

 suggests the idea that the duodenum forms a cavity, bounded somewhat 

 like the stomach, and that the contents of this cavity are continuously 

 driven from one end to the other. In our case the contents consist of 

 fat mixed with the fluids bile and pancreatic juice which act upon 



