1910. | Hydrochloric Acid in the Gastric Tubules. a 
superficial deposit of Prussian blue was very slight. The animal had received 
43 to 45 c. ems. of the injection solution by four subcutaneous injections of 
about 11 c¢.cms. each. One hour had elapsed between the first and second 
injections, and the remainder had been given at intervals of half-an-hour. 
A toxic effect was not observed. Food had been given prior to the 
beginning of the experiment. 
The experiments with these two rabbits (Rabbits 5 and 6) although differing 
in some respects, both in minor details in the method of procedure and in 
certain of the results obtained, possess essential features in common, namely, 
the subcutaneous administration of a large quantity of the injection solution 
during the space of a few hours, and the similarity of the situation in which 
the Prussian blue was ultimately found in the gastric mucosa. Instead of 
occurring within the parietal cells, the Prussian blue was found as a granular 
deposit scattered on their surface remote from the lumen. The cells 
frequently presented the appearance of being partly covered with a delicate 
pale blue film, punctuated with dark blue. (See Plate 8, fig. 14.) The 
deposit only occurred on certain of the cells. 
In many instances the surface of the cells was clear and the deposit was 
found in isolated areas, evidently lymphatic spaces, between the cells and 
close to the interstitial tissue adjacent to the external border of the tubule. 
In such areas, also, the dark blue granules appeared to be set in a pale blue 
ground substance. (See Plate 8, fig. 15.) 
Certain of the intertubular lymphatic channels, as well as other lymphatic 
vessels adjacent to the gland tubules, were found to be lined with a deposit 
of Prussian blue and frequently to contain large aggregations of the blue 
compound. The course of the lymphatic vessels could be readily followed 
from their blue content. (See Plate 8, fig. 13 and fig.16.) On the other 
hand, the central lumina of the gland tubules contained no Prussian blue. 
Wandering cells found between the tubules, and the lymph cells in the 
course of the larger channels, were frequently observed to be deeply 
impregnated with Prussian blue, and large phagocytic cells studded with 
blue granules were found in the submucous coat (Rabbit 5). (See Plate 8, 
fig. 17.) In certain of the preparations Prussian blue was also found in the 
contents of the blood vessels. (See Plate 8, fig. 16.) 
It is therefore evident that, under certain conditions the acid, instead of 
being wholly discharged into the canaliculi and thence into the central lumina 
of the yland tubules, may also be discharged in the’ inverse direction. 
Whether the occurrence of the Prussian blue in the lymphatic and blood- 
vessels thus reveals a normal tendency in the direction of the secretion 
or part of the secretion of the parietal cells, or whether the occurrence is 
