110 STUDIES IN CLINICAL PHYSIOLOGY 



The most reliable test for the presence of HCl is 

 Gunsberg's (phloroglucin and vanillin) ; this is too 

 well known to need description. It is merely a 

 qualitative test. 



By whichever method the estimation is made, it 

 would appear that diet exercises Httle or no effect 

 on the percentage of active hydrochloric acid, 

 although it so markedly affects the pepsin. Never- 

 theless, the percentage of acid is liable to change, 

 and the changes are of great value for both diagnosis 

 and treatment. 



Increased relative amount of HCl is particularly 

 common in gastric ulcer, so much so that an analysis 

 of a test-meal is of diagnostic importance. It is 

 also seen in duodenal ulcer, and, as has recently been 

 pointed out, in many other affections of the alimentary 

 canal, such as appendicitis. It is probable that the 

 cases which have been diagnosed as simple hyper- 

 chlorhydria have usually some latent disease, if not 

 in the stomach or duodenum, then in the gall-bladder, 

 kidney, or appendix, and removal of the offending 

 organ will cure the hyperchlorhydria. The charac- 

 teristic symptom of this condition is '' hunger- 

 pain," that is, a feeling of gnawing of the stomach, 

 which may be only a discomfort or may amount to 

 positive pain ; it occurs two or three hours after a 

 meal, and is relieved by food or alkalies. It is proba- 

 bly due to the spasmodic contraction of the pylorus 

 set up by the long persistence of the acidity on the 

 duodenal side. Another view is that it is caused 

 by incipient self-digestion of the stomach. This is 

 normally guarded against by an anti-pepsin in the 



