48 E. J. STIEGLITZ 



The urine in the bladder at death was strongly positive for iron. 



Histological findings (fig. 1): In the cortex of the kidney prepara- 

 tions of this experiment the Prussian blue was found to some extent in 

 the lumina of the convoluted tubules and in a finely granular form in 

 the cytoplasm of the cells, just under the brush border. There was 

 also considerable iron in the lumina of the thick limbs of Henle's loops 

 and also in the lumina of the medullary collecting tubules. None was 

 found in the blood-vessels in the sections. 



Thirty minutes {K26). Adult female rabbit. Weight = 1770 

 grams. Injected 0.4 gram green ferric ammonium citrate plus 0.4 gram 

 sodium ferrocyanide. Animal killed thirty minutes later. Kidneys 

 fixed in: 



Absolute alcohol. 



Carnoy's fluid plus trichloracetic acid. 

 Zenker's fluid plus trichloracetic acid. 

 5 per cent trichloracetic acid. 



The urine in the bladder at death was strongly positive for iron. 



Histological findings: There was more iron to be seen in the cortex 

 of the sections of this experiment than in the medulla; the greater 

 portion of this cortical iron was in the form of finely granular clumps 

 in the cytoplasm of the cells of the convoluted tubules, in the half 

 toward the lumen, and in some cases apparently stuck to the brush 

 border. Very little indeed was in any other position than this in the 

 cells of the so-called secreting tubules. Prussian blue was also present 

 in the lumen of collecting tubules, both of the medullary rays and of 

 the medulla proper. 



Thirty-seven minutes (KIO). Large albino male rabbit. Injected 

 0.7 gram brown ferric ammonium citrate intravenously. Animal killed 

 thirty-seven minutes later. Kidneys fixed in: 

 95 per cent alcohol. 

 Zenker's fluid. 



The urine in the bladder was strongly positive for iron. 



Histological findings: Practically every collecting tubule in the 

 medulla of the sections of this experinient contained much iron in its 

 lumen. The straight tubules of the medullary rays also gave a strong 

 Prussian-blue reaction. It was noticeable that many of the convoluted 

 tubules in the section were negative for iron, and that those which did 

 contain iron varied greatly in the extent of their reaction. In some 

 cases the cells were heavily laden at their peripheral border at the 

 lumen, while others retained only a smaller amount. The localization 

 of the iron in the cells was the same as described just above. 



Three hundred and thirty minutes (K13). Medium-sized female 

 0.8 rabbit. Injected 0.8 gram brown ferric ammonium citrate intra- 

 venously. The animal showed toxic symptoms from the brown salt. 

 Died five and one quarter hours later. Autopsied at once. Kidneys 

 fixed in: 



95 per cent alcohol. 

 Zenker's fluid. 



