158 PHYSIOLOGICAL CHEMISTRY. 



THE EXAMINATION OF STOMACH CONTENTS. 



From the clinical standpoint the examination of the con- 

 tents of the stomach at any given time is a matter of consider- 

 able importance. The examination may extend to the detec- 

 tion or recognition of the nature of various solid products 

 present, but ordinarily it is confined to the detection or esti- 

 mation of the acid and the enzymes on which the functional 

 activity of the organ depends. For such examinations it is 

 necessary to collect the liquid contents of the stomach by the 

 aid of some kind of stomach tube. Vomited matter may be 

 used for the same tests. In any event it is preferable to have 

 as much of the solid contents as possible along with the liquid. 



Inasmuch as the secretion of the gastric juice does not take 

 place all the time, as was pointed out above, but depends 

 largely on the action of certain stimuli, of which the passage 

 of food down into the stomach is the common and most impor- 

 tant one, it is customary to encourage the flow of the secre- 

 tion by giving what is called a " test meal " some time before 

 introducing the stomach tube. Unless this is done it might 

 be possible to collect from the stomach a liquid practically 

 free from either acid, or enzyme. The Ewald test-meal con- 

 sists of wheat bread and water or tea without sugar; 50 gm. 

 of bread to 400 cc. of water is an average meal. The content 

 of protein in this would amount to less than 5 gm. ordinarily, 

 and in the normal stomach enough hydrochloric acid to more 

 than combine with this would soon be secreted. After about 

 an hour therefore " free " acid should be detected by- the tests 

 given below. With a meal richer in proteins more time would 

 be consumed in producing an excess of hydrochloric acid. In 

 such a case two or three hours might elapse before it would 

 be possible to detect the free acid. The Riegel test-meal con- 

 sists of a plate of broth or soup, 200 gm. of beefsteak, 50 gm. 

 of wheat bread and 200 cc. of water. The protein in this 

 would amount to about 60 gm., which would require 2 to 3 

 gm. of hydrochloric acid for preliminary saturation. Some 

 hours would therefore be consumed in producing this. The 



