102 



THE WORK OF THE DIGESTIVE GLANDS. 



therefore endeavoured to supply its place by some other mean?. Before 

 each feeding we washed out the dog's stomach, then introduced 200- 

 :>(>() c.c. of meat broth and waited till it became strongly acid, that is to 

 say, till the gastric glands were thrown into vigorous activity. Not 

 till then did \ve introduce solid food. By this means the food, which 

 otherwise began to decompose, was satisfactorily digested. 



In dealing with the secretory processes, we have up to the present 

 almost exclusively confined ourselves to the quantity of juice secreted 

 upon the different foods. But from the second lecture, we know that 

 the quality of the juice with the different kinds of foods also varies. 

 How is this alteration produced ? As we have already repeatedly stated, 

 the psychic juice for all kinds of food possesses a uniform digestive 

 power. Consequently, the variations of digestive power in the juice 

 secreted during the later hours after the eating of food, must be pro- 

 duced by the dissimilar chemical influence of the different foods. 



In our investigation we started from the fact that a much stronger 

 juice is poured out on bread than upon flesh. On what does this 

 difference depend ? There were a whole series of possibilities. It 

 might be due to the physical properties of the food, or to the special 

 nature of the proteid substances of bread and flesh respectively, or 

 finally to the amalgamation of starch with the proteid of the bread. 

 The first supposition was easily set aside. Meat may be desiccated, or 

 bread again moistened, without the relationships in the digestive powers 

 of the juices being altered (Dr. Chigin\. The third hypothesis was 

 then tested (Dr. Lobassoff). We mixed flesh and pure starch paste in 

 the same proportions in which the proteid and starch of bread are 

 found, gave this artificial bread to our dogs to eat, and obtained, as a 

 matter of fact, a juice of like digestive power to that secreted on 

 ordinary bread. 



