66 Miss M. P. FitzGerald. The Origin of the [June 4, 
but Heidenhain had previously suggested this as possibly responsible for 
such cells being stained by anilin blue.* 
Sehrwald found that if hydrochloric acid was added to a dilute solution of 
anilin black, which is of a blue colour in transmitted light, the blue was 
unchanged, but that, on the addition of alkali, the colour changed to a dirty 
pale violet, with no resemblance to that of the original solution. On the 
addition of potassium bichromate, the blue and pale violet colour disappeared 
respectively from the acid and alkaline solutions, but a striking difference was 
observable in the intensity and character of the colour then attained, the 
acid solution being grey blue, and the alkaline pale grey; with highly 
concentrated solutions, the colour difference obtained was similar to that 
shown by Grtitzner to prevail in the parietal and chief cells of prepara- 
tions of the gastric mucosa stained by anilin black. Sehrwald therefore 
concluded that the darkly-stained parietal cells, described by Griitzner, 
were richer in acid, and the pale grey chief cells more alkaline, and that 
these results furnish evidence of acid formation in the parietal cells. 
Frankelf repeated the alizarin experiment of Edinger on the dog, and fully 
confirmed the results obtained by the earlier investigator, but could not 
determine in which cellular element the acid occurred. He also points 
out that an objection can be raised to the use of sodium alizarin for 
the end in view, since the reaction may be brought about by acid resulting 
from dissociation of the neutral salt. 
Frankel therefore turned his attention to another reagent. Following the 
method employed by Dresert to demonstrate the presence of acid in 
muscle during activity, he injected into the jugular vein of a dog a 5-per-cent. 
solution of acid fuchsin, previously decolourised with either caustic soda or 
with carbonate of soda, the latter being usually employed. The amount 
injected varied from 50 to 100 c.cms., according to the size of the animal. 
Prior to injection, the gastric juice of the dog to be experimented upon 
was tested with phloroglucin and vanillin and with Congo paper. The dogs 
used were in full digestion. As result, the mucosa, macroscopically, was 
seen to be of a beautiful red colour, the pylorus region included, while the 
cesophagus and duodenum were uncoloured. From the microscopical examina- 
tion of teased portions of the mucosa placed in a drop of distilled water, he 
found both the parietal and chief cells, readily distinguishable one from 
another, intensely red, the colour of both kinds being of equal intensity. 
* Heidenhain, ‘ Handbuch d. Physiol., Hermann,’ 1883, vol. 5, p. 150. 
+ S. Frankel, zbid. 
+ H. Dreser, ‘Centralb. f. Physiol.,’ 1887, vol. I. 
