04 THE WORK OF THE DIGESTIVE GLANDS. 



influence the secretory process either by causing pain, or in some 

 other way. In passing the t-ound, vomiting movements may be set 

 up, which, it cannot be denied, may in certain ways affect the work 

 of the glands. Further, in spite of every precaution, during the 

 withdrawal of the sound, a few drops of the liquid injected not 

 infrequently fell on the mucous membrane of the mouth, and these 

 drops may have awakened the idea of food in the dog's mind. All this 

 is, of course, avoided by the fistula leading into the large stomach. 

 The substances may even be introduced when the animal is asleep, with- 

 out waking it. Moreover, not only fluids, but also more consistent 

 substances, may be employed in this way. 



It was natural to commence the investigation with water the 

 simplest and, from its wide occurrence, the most important constituent 

 of the food. Has water an exciting effect upon the gastric glands? 

 From a long series of experiments we have arrived at the conviction 

 that it has. When, for instance, in the case of our dog with the 

 two stomachs, we introduced 400 to 500 c.c. of water into the larger 

 cavity, we always obtained a secretion of gastric juice (Dr. Chit/in), 

 though not a large one. The constancy of the result, and especially 

 the regularity of the quantity of juice secreted, clearly indicated that 

 no accidental condition, such as a mental effect, came into play. We 

 have, however, both earlier and later experiments at hand which remove 

 every doubt concerning the stimulating influence of water. Heiden- 

 hain had long ago shown that a secretion began from the gastric 

 cul-de-sac, isolated by his method, as soon as water was introduced 

 into the main cavity. The same phenomenon was likewise observed 

 at a later period by Professor Ssanozki. In such a case the possi- 

 bility of a j sychic excitation of the secretion is excluded, owing to 

 the division of the vagus nerve fibres. For instance, in dogs whose 

 vagi were cut below the diaphragm, Dr. Jiirgens never saw a secre- 

 tion of gastric juice as the result of sham feeding. As soon, how- 

 ever, as water was poured into the stomach, an undoubted secretion 

 occurred. Finally, I have myself always obtained a secretion from the 

 introduction of water in dogs which I succeeded in keeping healthy 

 for several months after the vagi nerves were divided in the neck. 

 Hence water must be accepted as a chemical excitant of gastric secre- 

 tion, if only a weak one. Thus, if instead of 500 c.c., only 100 c.c. 

 to 1 50 e.c. of water be injected into the large stomach of a dog with 

 the isolated pouch, very often that is to say, in about half the cases 

 not the least trace of secretion is to be seen. It is only a prolonged 

 and widely spread contact of the water with the gastric mucous mem- 

 brane, which gives a constant and positive result. 



Before passing, I wish further to emphasise the fnct that section of 



