THE WORK OF THE DIGESTIVE GLANDS. 



diverse relations between the content of water and the richness of the 

 juice in ferments; a strong digestive power may recur both with a 

 copious as well as with a scanty secretion. In one and the same 

 juice, the different ferments may suffer variations running courses 



independently of each other, a 



HOURS i n in rv if in IV fact which undoubtedly shows 



that glands such as the pancreas, 

 which possess a complex chemical 

 activity, .are able to furnish, 

 during given periods of their 

 secretory work, now one product 

 and now another. That which 

 has been said of theferments may 

 also be applied to the quantities 

 of salts present in the juices. 



All the more interesting, 

 therefore, appears the fact, as 

 one must accept it, that the 

 gastric juice possesses a con- 

 stant acidity. It is true that 

 clinical investigations of the 

 secretory activity of the human 

 stomach are almost daily con- 

 cerned with variations of acidity, 

 and even in our observations, 

 where we deal with absolutely 

 pure juice, such fluctuations are 

 also to be seen. But a careful 

 investigation of all the data 

 leads to the almost indubitable 

 conclusion that the juice, as 

 it is poured out by the glands, 

 always possesses the same degree 

 of acidity. We do not, how- 

 ever, receive the juice directly 

 from the glands, even in our 

 method. After it is secreted by these it has to flow down over the 

 alkaline mucous membrane and inevitably becomes partially neutralised, 

 that is to say, has its acidity reduced. To this circumstance must be 

 attributed the apparent fluctuations of acidity, as is clearly shown by 

 numerous observations. It is a rule almost without exception that the 

 acidity of the juice is closely dependent upon the rate of secretion ; the 

 more rapid the latter, the more acid the juice, and vice versa. This rela- 



FlG. fi. Ferment content in hourly portions 

 of pancreatic jnico after a meal of 600 

 c.c. milk. 



