FORMATION OF HYDROCHLORIC ACID IN THE FOVEOL/E. 239 



EXPERIMENTS WITH INDICATORS: THE REACTION OF THE SECRE- 

 TION WITHIN THE LUMEN OF THE ACTIVE FUNDUS GLAND, 

 AND WITHIN THE INTRACELLULAR CANALICULI 

 OF THE PARIETAL CELLS. 



It is obvious from the observations of Fitzgerald and ourselves 

 reported in the preceding section that the Prussian blue reaction 

 is not a trustworthy indication of the place of formation of the 

 hydrochloric acid of the gastric juice, and that we must look 

 to other methods for a solution of this problem. One naturally 

 turns to the chemical indicators for this purpose. The results 

 obtained by means of these substances by previous investigators 

 who have employed them have been uniformly unsatisfactory 

 and unconvincing. The most definite results obtained by these 

 methods are those reported by Frankel ('91) who used neutral 

 sodium rosanilinsulphonate as an indicator, and by Edinger 

 ('79), who employed a solution of sodium alizarin. 



Rosanilin sulphonic acid possesses the property of forming 

 with sodium hydroxide acid salts which form red solutions (acid 

 fuchsin), and neutral salts whose solutions are colorless. The 

 addition of small quantities of acid to solutions of the neutral 

 salt results in the production of the red colored acid salt. Ac- 

 cordingly, Frankel injected into the jugular veins of dogs 50- 

 100 c.c. of a 5 per cent, solution of the neutral sodium rosanilin 

 sulphonate. As a result of this proceeding he found the entire 

 mucous membrane of the stomach, including the pyloric mucous 

 membrane, stained brilliant red. Teasing portions of the mucous 

 membrane in distilled water he found that both parietal and chief 

 cells were stained in the fundus glands, and that the cells of the 

 pyloric glands were also stained, while the cylindrical cells of 

 the surface were unstained. He could see no difference in the 

 intensity of the stain in the two types of cells. The same experi- 

 ment was also performed on rabbits, but in this case he found 

 that the color was not uniformly distributed throughout the 

 mucous membrane, and the pyloric mucosa showed only a few 

 slightly red spots. 



From these experiments Frankel concludes: that the mucous 

 membrane of the stomach has an acid reaction; that the acid is 

 formed in the parenchyma cells; and that it can always be 



