of the University of Pennsylvania. 39 



iodide, even in relatively minute quantity, of pre- 

 cipitating acid albumen in solutions, which shall, 

 after its addition, possess the normal degree of 

 acidity of human or even canine gastric juice. The 

 same may be said of potassium bromide and of sev- 

 eral other analogous compounds. The precipitation 

 effected by the iodide is so complete that when solu- 

 tions of acid-albumen are thus treated and filtered, 

 the still acid filtrate yields no trace of proteid mat- 

 ter. This observation, which is doubtless old, 

 though I have been as yet unable to find it re- 

 corded, tends to show that the time at which the 

 administration of this drug is least liable to disturb 

 digestion is either during or immediately after the 

 ingestion of food. 



There are several t sources of error in attempts at 

 deduction from the results of artificial digestion, as 

 ordinarily performed. Thus the continued activity 

 of a digestive fluid is largely conditioned by the re- 

 moval of the products of its action soon after their 

 formation. This occurs in the living viscus, but 

 not in the test-tube of the experimenter. The 

 maintenance of the normal temperature of the ac- 

 tive stomach is, of course, readily accomplished, but 

 the conscientious imitation of other factors in the 

 normal digestive process implies not only a constant 



