1 92 GASTRIC DIGESTION 



parts, which are drops of gastric juice ; and these gradually increase in 

 size until the liquid trickles down the sides in small streams. The 

 membrane is now invariably of a strongly acid reaction, while at other 

 times it is either neutral or faintly alkaline. The thin watery liquid 

 thus produced is the true gastric juice. 



While natural food is the proper stimulus for the stomach, and while, 

 in normal digestion, the quantity of gastric juice is perfectly adapted to 

 the work it has to perform, it has been noted that savory and highly 

 seasoned articles ordinarily produce a more abundant secretion than 

 those which are comparatively insipid. An abundant secretion is like- 

 wise excited by some of the vegetable bitters and even by the sight or 

 odor of articles of food. 



The recent observations of Pawlow, of St. Petersburg, recall the 

 early brilliant experiments of Claude Bernard. Pawlow established an 

 opening in the stomach in the following way : He separated a small 

 portion of the organ from the main cavity completely, so that there 

 remained only an external opening into the portion thus isolated. 

 This is called Pawlow's pouch, or miniature stomach. After feeding, 

 the gastric juice flowed from this pouch clear and unmixed with debris 

 of food. He was thus enabled to obtain pure gastric juice and study 

 its properties, and to avoid sources of error in experiments made with 

 gastric juice artificially prepared. 1 



In the experiments of Pawlow some of whose conclusions are cer- 

 tainly remarkable, not to say extravagant it appeared that the juice 

 flowing from the miniature stomach after feeding with different articles 

 presented marked differences in proteolytic activity. The proteolytic 

 action was most vigorous after feeding with bread ; and the juice 

 collected at this time he called "bread-juice." The proteolytic power 

 was measured by noting the quantity of food, contained in a graduated 

 tube, that was dissolved in a certain time ; and bread-juice was found 

 to have an activity of 6.64 millimeters. The juice obtained after feed- 

 ing with meat had an activity of 3.39 millimeters. The activity after 

 feeding with milk was still less, being only 3.26 millimeters. Perhaps 

 the most striking observations were made on dogs with " sham-feeding." 

 In these experiments, the oesophagus was divided in the neck, leaving 

 two openings, so that the food swallowed did not pass into the stomach. 

 When food was taken in this way, pure gastric juice flowed in abun- 



1 MM. Cade and Latarjet have recently observed a case of " miniature stomach " of nearly 

 twenty years' standing in a young girl, following a hernia of part of the stomach in the median 

 line, occurring in early infancy. This little pouch had become isolated from the rest of the 

 organ. Nearly all the observations o^f Pawlow on dogs were confirmed in this case. The 

 fistula was finally closed by operation. Journal de physiologic et de pathologie generate, Paris, 

 Mars, 1905, tome vii, p. 221. 





