120 



THE WORK OF THE DIGESTIVE GLANDS. 



which became evident in certain cases during the activity of the pan- 

 creatic gland. As we have already related, solutions of alkalies and of 

 alkaline salts of the alkali metals not only do not excite a flow of 

 pancreatic juice but even exert an inhibitory action. I will describe 

 the experiment more exactly. The secretory influence of the solutions 

 in question was compared with that of water, and in every case the 

 flow of pancreatic juice was considerably less with the former. I give 

 here some figures taken from the article of Dr. Becker. 

 The fluid was collected and recorded every half-hour. 



250 c.c. water poured 

 into the stomach. 



5"6 c.c. 

 9-9 

 6-2 



2 grins, of NaHCO 3 given in 

 250 c.c. of water. 



4-2 c.c. 



o-o 



1-0 . 



250 c.c. water poured 

 into the stomach. 



18-0 c.c. 

 7-3 



The inhibitory efl'ect was also investigated in another way, in which 

 it was particularly observed how long such influence lasted. The solu- 

 tion to be investigated was poured into the stomach of a dog by means 

 of the tube. An hour later the animal received its ordinary meal and 

 the resulting secretion was compared with the normal. In every case a 

 marked diminution of the secretion was to be seen. Once more I give 

 an example from Dr. Becker's article. 



The secretion was recorded every hour. 



The dog was given 1200 c.c. 

 milk and 2 Ib. of meat. 



4G'(5 c.c. 



4.V4 



r>3-."> ., 



is-i 



22-4 



18-7 , 



Total 204-7 



Two hours before the feeding 



the dog was given 400 c.c. 



of Essentucky water. 



32'2 c.c. 

 56-3 

 21-5 

 1-V7 

 12-0 

 14-4 , 



Total 152-1 



The same food without the 

 Essentucky water. 



42-3 c.c. 

 62-1 

 46-4 

 21-4 

 14-5 

 13-1) , 



Total 200-6 



And here I ask you to recall to mind what I said to you in the first 

 lecture, c mcerning the efl'ects of a continued addition of sodium bicar- 

 bonate to the food. Such an addition for a length of time markedly 

 depresses the secretory activity of the pancreas, which comes down to 

 an unusually low point. 



Hence the fact that some substances diminish the secretion of pan- 

 creatic juice is very striking, and cei'tainly deserves our consideration. 

 How we are to interpret the mechanism of inhibition remains still 

 obscure. It is at present difficult to decide whether we have only a local 

 effect on the peripheral terminations of the reflex-transmitting nerves, 

 or whether an influence is also produced through the blood. That the 



