222 DIGESTION. 



the wound closed by sutures passed through the integument, 

 muscles, and peritoneum. 



The dog will generally eat on the second or third day 

 after the operation ; and peritonitis aside from the inflam- 

 matory action which agglutinates the stomach at the site of 

 the operation to the walls of the abdomen rarely follows. 

 It is best to feed the animal sparingly a short time before 

 operating, as there is some difficulty in seizing the stomach 

 when it is entirely empty. 



Having thus established a permanent fistula into the 

 stomach, after the wound has cicatrized around the canula, 

 the animal suffers no inconvenience, and may serve indefi- 

 nitely for experiments on the gastric juice. Many physiol- 

 ogists have been in the habit of exciting the flow of this 

 fluid by the introduction into the stomach of pieces of ten- 

 don, or hard indigestible articles, on the ground that the 

 fluid taken from the fistula, under these circumstances, is 

 unmixed with the products of stomach digestion ; but it has 

 been . shown that the quantity and character of the juice is 

 influenced by the nature of the stimulus which causes its se- 

 cretion ; and it is proper, therefore, to excite the action of the 

 stomach by articles which are relished by the animal. For 

 this purpose, lean meat may be given, cut into pieces so small 

 that they will be swallowed entire, and first thrown into 

 boiling water so that their exterior may become somewhat 

 hardened. The cork is then removed from the tube, which 

 is simply freed from mucus and debris, when the gastric 

 juice will begin to flow, sometimes immediately, and some- 

 times in from three to five minutes after the food is taken. 

 It will flow in clear drops or in a small stream for about 

 fifteen minutes, nearly free from the products of digestion. 

 At the end of this time it is generally accompanied with 

 grumous matter, and the experiment should be concluded if 

 it be desired simply to obtain the pure secretion. In fifteen 

 minutes, from two to three ounces of fluid may be obtained 

 from a good-sized dog, which, when filtered, is perfectly 



