SOURCE OF THE ACIDITY OF THE GASTRIC JTHCE. 24:1 



all the salivary ducts were tied before the fluid was taken 

 from the stomach. 



The first step was to take about one hundred grammes of 

 cold gastric juice, strongly acidulated with nitric acid, and 

 precipitate it with nitrate of silver. The chloride of silver, 

 free from organic mixture, was then separated by filtration 

 and weighed, the total quantity of chlorine being calculated 

 therefrom. After having precipitated the excess of the salt 

 of silver in the filtered fluid by hydrochloric acid, the liquid 

 was calcinated in a porcelain vessel, and the total quantity 

 of bases estimated. Having thus obtained the proportion 

 of bases and the total quantity of chlorine, it is evident 

 that if this quantity be more than sufficient to saturate the 

 bases, the chlorine must exist in some other form, which 

 is supposed by Schmidt to be that of hydrochloric acid. It 

 was found, indeed, that .the quantity of chlorine was greater 

 than the equivalent of the bases estimated. 



The second step was to determine, by saturating the acid 

 of the gastric juice with potassa, lime, or baryta, the propor- 

 tion of free acid. It was found by this process that the 

 quantity of free acid nearly corresponded with the excess of 

 chlorine over the quantity estimated as combined with bases 

 in the previous experiment. 



In this process, the ammonia is necessarily lost during; 

 calcination; but in subsequent experiments, this substance 

 ,was found to be constantly present, but in inconsiderable 

 quantity. It was also assumed to be experimentally demon- 

 strated that no organic acid, with the elements, C.H.O., ex- 

 isted in the gastric juice, except in infinitesimal quantity. 



These experiments afford the strongest arguments in fa- 

 vor of the view that hydrochloric acid is the free acid of the 

 gastric juice ; but on the other hand, facts have been brought 

 forward, some of which have already been referred to,, which 

 show that this acid cannot here exist in a free state. 



One of the most important of these facts is, that the addi- 

 tion of a small quantity of oxalic acid to gastric juice produces 

 16 



