1910.] 
Fig. 2—Diagram of Dorsal Wall of Opened Stomach of Rabbit (Rabbit 5), illustrating 
region in which Prussian blue deposit usually occurred, maximum intensity of 
occurrence of reaction, and unusual area covered by deposit in pyloric region. 
bar 
2 size. 
the blue compound, and this coloration extended for a considerable depth 
beneath the contiguous layer in the region of the cesophageal opening and 
of the lesser curvature adjacent to it. On the other hand, the contents of 
the fundus and of the superior half of the organ, as well as the greater 
portion of the contents of the pyloric region, were of the yellow colour 
normally found with a carrot diet, and exhibited no trace of the presence of 
Prussian blue. 
On testing the filtrates obtained by extracting portions of the contents 
removed from (1) the fundus region; (2) the region of the cesophageal 
opening and of the lesser curvature adjacent to it; and (3) the pyloric 
region, proof was not obtained of the presence of either the iron salt or 
potassium ferrocyanide in the filtrate of the fundus contents, but the Prussian 
blue reaction occurred to a marked degree in the filtrate of region (2), and 
to a slight degree in that of region (5), on the addition of a small quantity 
of 0°5 per cent. hydrochloric acid and of one drop of a 1°5-per-cent. solution 
of potassium ferrocyanide, bearing witness to the presence of an iron salt, and, 
therefore, to the salt in question, or possibly to more than one of the factors 
necessary to the reaction, being mixed more particularly with the contents of 
region (2). 
The contents of the intestines, similarly extracted, and the bile were 
likewise tested, but with negative results. 
On the addition of 0°5 per cent. hydrochloric acid the Prussian blue reaction 
was obtained in the urine voided four hours after the first injection. Further 
interesting points observed in the same rabbit (5) will be dealt with later. 
In some instances the examination of sections of the tissue underlying the 
superficial deposit of Prussian blue furnished no evidence of the presence of 
