GASTRIC DIGESTION 



147 



be found that the rubber bag has passed through the stomach unopened. If the 

 methylene blue is found in the urine inside of 18-20 hours a satisfactory gastric 

 function is indicated. 



For Einhorn's bead method for the study of digestive function see chapter on 

 Feces. 



8. Testing the Motor and Functional Activities of the Stomach. This 

 test is performed the same as Experiment 20 under Salivary Digestion, page 60. 

 If the experiment was carried out under salivary digestion it will not be neces- 

 sary to repeat it here. 





cc 



96 



6C 



Wnfca. 



FIG. 43. CURVES SHOWING STIMULATORY POWER OF BEEF EXTRACT 

 (Plotted from unpublished data collected in the author's laboratory by Professor Chester C. 



Fowler.} 



This test does not serve as an index of gastric absorption as is sometimes stated. 

 It has been shown by von Mering, for example, that potassium iodide is not ab- 

 sorbed from the stomach for 2-3 hours. Hence when iodine appears in the saliva 

 a few minutes after the KI is ingested this fact would indicate absorption from the 

 intestine. The gastric mucosa is not importantly related to absorption. 



9. Influence of Bile. Prepare three tubes as follows: 



(a) Five c.c. of pepsin-hydrochloric acid solution + 0.5-1 c.c. of bile. 



(b) Five c.c. of pepsin-hydrochloric acid solution -f 5 c.c. of bile. 



(c) Five c.c. of pepsin-hydrochloric acid solution. 



