82 DIGESTION AND RESORPTION 



could be done in two different ways, either by giving 

 the food to the animal, generally a dog, to eat, or by 

 putting the food into the stomach direct, by a tube 

 ending in the stomach — the different juices, gastric, 

 pancreatic or enteric, are secreted by the animal. 

 These different juices may be collected by tubes 

 introduced into the different fistulae. 



The production of gastric juice begins about ten 

 minutes after the introduction of food. The total 

 time of secretion is observed and the quantity of juice 

 secreted during this time. Very often the quantity 

 of juice secreted during a certain time, e.g. one hour 

 or three hours, reckoned from the beginning of the 

 process, is also given. The quantity of undigested 

 food may in the same manner be taken out from the 

 stomach after a given time and analysed, in which 

 case a correction is applied for the quantity of ac- 

 companying gastric juice, determined from the acidity 

 of the content in the stomach. In order to study 

 the stomachical secretion free from the food taken, 

 another method has been used. A small part of 

 the stomach is separated from the rest of the stomach 

 by sewing, whereby a tube is formed, which is open 

 so that its secretions may be collected in calibrated 

 tubes. Special experiments have shown that the 

 juice secreted from the "small stomach," or portion 

 thus separated off, is of the same composition as that 

 secreted from the corresponding part — the fundus 

 part or the pyloric one of the stomach — and that it 

 is always the same fraction of the total secretion. 

 This method has been used by Lonnquist and 



