232 



DIGESTION. 



FiG. 59. Gastric fistula. (Bernard.) 



E, stomach ; D, duodenum ; M, muscles of the abdomen, di- 

 vided ; O, opening of the fistula. 



The dog will generally eat on the second or third day after the operation ; and perito- 

 nitis aside from the inflammatory 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 established a permanent fistula into the stomach, after the wound has cica- 

 trized around the canula, the animal suffers no inconvenience and may serve indefi- 

 nitely for experiments on the gastric 

 juice. Many physiologists have been in 

 the habit of exciting the flow of this 

 fluid by the introduction into the stom- 

 ach of pieces of tendon or hard, indi- 

 gestible articles, on the ground that the 

 fluid taken from the fistula, under these 

 circumstances, is unmixed with the pro- 

 ducts of stomach-digestion ; but it has 

 been shown that the quantity and char- 

 acter of the juice are influenced by the 

 nature of the stimulus which causes its 

 secretion, and it is proper, therefore, to 

 excite the action of the stomach by ar- 

 ticles 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 freed from mucus and debris, when 



the gastric juice will begin to flow, sometimes immediately 

 and sometimes in from three to five minutes after the food 

 has been taken. It flows 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 accom- 

 panied with grumous matter, and the experiment should 

 be concluded if it be desired simply to obtain the pure se- 

 cretion. In fifteen minutes, from two to three ounces of 

 fluid may be obtained from a good-sized dog, which, when 

 filtered, is perfectly clear; and this operation may be re- 

 peated three or four times a week without interfering with 

 the quality of the secretion or injuring the health of the 

 animal. 



Although instances of gastric fistula in the human sub- 

 ject had been reported before the case of St. Martin and 

 have been observed since that time, the remarkably healthy 

 condition of the subject and the extended experiments of 

 so competent and conscientious an observer as Dr. Beau- 

 mont have rendered this case memorable in the history of 

 physiology. It is undoubtedly the fact that this is the only 

 instance on record in which pure, normal gastric juice has 

 been obtained from the human subject; and it served a 

 most important purpose as the standard for comparison of 

 subsequent experiments on the inferior animals. The de- 

 tails of this case, condensed from the monograph of Beau- 

 mont, are briefly the following : 

 Alexis St. Martin, a Canadian voyageur in the service of the American Fur Company, 



FIG. 60. Dog with a gastric fistula. 

 (Beclard.) 



