240 B. C. H. HARVEY AND R. R. BENSLEY. 



demonstrated in them. Regarding the acid reaction obtained 

 by this method in the pyloric region he does not venture an 

 interpretation. 



The results obtained by Edinger by means of the sodium 

 alizarin reaction were similar to those of Frankel. Sodium ali- 

 zarin, as Edinger pointed out is, in neutral solutions, of a deep 

 purple reel color, while the addition of an acid results in the pre- 

 cipitation of the alizarin as a flocculent yellow precipitate. 

 Edinger prepared the solution by adding alizarin in excess to a 

 10 per cent, solution of sodium hydroxide. Then the solution 

 was filtered. 25-100 c.c. of this solution were injected into the 

 jugular veins of rabbits and dogs. In a rabbit he found after 

 this injection the stomach spotted red-violet and yellow, the 

 latter being more general in the region of the greater curvature, 

 though the pyloric mucous membrane was also yellow. He 

 concludes that the glands of the rabbit's stomach are not all in 

 activity at the same time, and that both the fundus and pyloric 

 mucous membranes react acid. In dogs, after similar treatment, 

 the whole mucous membrane of the stomach, including that of 

 the pyloric region, was yellow. Sections of the mucous mem- 

 brane showed that the yellow color was to be found at all levels, 

 but the intensity of the stain was too slight to permit of the 

 recognition of the stain in particular cells. The pancreas also 

 gave an acid reaction. 



Experiments w r ith tropeolin, congo red, litmus, phenol- 

 phthalein, and other indicators in common use, have been with- 

 out result or, at the most, have only indicated what was known 

 from examination of the secretion, namely, that the contents of 

 the stomach were acid. 



It is obvious from the foregoing statements that the results of 

 the experiments of Edinger and Frankel with sodium alizarin 

 and sodium rosanilin sulphonate were not in accord with what 

 had been previously determined concerning the place of forma- 

 tion of hydrochloric acid in the stomach, inasmuch as they 

 indicated the formation of acid in the pyloric mucous membrane 

 which had previously been shown by Heidenhain ('70) and 

 Klemensiewicz ('75) to secrete an alkaline fluid. Moreover, 

 neither of these experiments gave any clear indication of the 

 ource of the hvdrochloric acid. 



