GASTRIC JUICE. 



217 



gastric juice : The subject was placed on the right side in the recumbent 

 posture, the valve was depressed within the aperture, and a gum-elastic tube, 

 of the size of a large quill, was passed into the stomach to the extent of five 

 to six inches (12 to 15 centimetres). On turning him upon the left side 

 until the opening became dependent, the stimulation of the tube caused the 

 secretion to flow, sometimes in drops and sometimes in a small stream. 



Since the publication of Beaumont's experiments, many observations 

 have been made upon animals in which a permanent gastric fistula had been 

 established. In these experiments the dog is most frequently used, as in this 

 animal the operation usually is successful. The animals operated upon by 

 Bassow, who was the first to establish a gastric fistula (1842), were merely 

 objects of curiosity ; but Blondlot (1843) and others fixed a tube in the 

 stomach, collected the juice and made important observations with regard to 

 its action in digestion. Most experimenters follow the method employed by 

 Blondlot and Bernard, making the opening in the abdomen in the median 

 line, a little below the ensiform cartilage. 



Having established a permanent fistula into the stomach, after the wound 

 has cicatrized around the canula, the animal suffers no inconvenience and 

 may serve indefinitely for experiments on the 

 gastric juice. In some experiments, the flow of 

 gastric juice has been excited by the introduc- 

 tion into the stomach, of pieces of tendon or 

 hard, indigestible articles, on the ground that 

 the fluid taken from the fistula, under these con- 

 ditions, is unmixed with the products of gastric 

 digestion ; but it has been shown that the 

 quantity and character of the secretion are in- 

 fluenced by the nature of the stimulus, 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 some- 

 what hardened. The cork is then removed from 

 the tube, which is freed from mucus etc., when 

 the gastric juice will begin to flow, sometimes 

 immediately and sometimes in four or five min- 

 utes 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 diges- 

 tion. 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, two to three ounces (60 to 

 90 c.c.) of fluid may be obtained from a good-sized dog, which, when filtered, 

 is perfectly clear ; and this operation may be repeated three or four times a 



FIG. 64. Dog with a gastric fistula 

 (B6clard). 



