OF THE ALIMENTARY CANAL 109 



stomach, of which he was able to obtain a graphic 

 record. 



VARIATIONS IN THE HYDROCHLORIC ACID OF 

 THE STOMACH. 



The amount of acid normally present as free HCl 

 is given differently by different physiologists, some 

 following Topfer and relying on amido-azo-benzol as 

 the indicator, others using the more accurate but 

 somewhat tedious method of Willcox.* 



It has been customary to take the normal quantity 

 of free HCl as o-2 per cent, but Panton and Tidy 

 and other workers show that o-i is more accurate. 

 The total gastric acidity is about 50 c.c. of dccinormal 

 acid. 



The contradictory results obtained by various 

 workers are worthy of explanation. The significant 

 figure, the o-i per cent of HCl, means (a) HCl which 

 has already got to work on and combined with 

 protein in the food, together with [b) any free HCl still 

 unattached. Obviously, a larger or more albuminous 

 test-meal would reduce the free HCl still further in 

 any stomach, however normal the acidity. In spite 

 of this, some still prefer to estimate the free HCl and 

 to regard it as the significant figure ; they take the 

 normal to be 0-02 per cent after a test-meal, the 

 remaining O'cS having combined with the food. 



The total acidity of course includes lactic acid and 

 any other fermentation acids, also acid phosphates, 

 and is of no great importance. 



• Lancet, 1905, i, p. 1566. 



