294 Proceedings Columbia Biochemical Association [Jan. 



servations by Liebermann^"* (whose work on colored Compounds 

 produced from phenols has been of great importa'nce ) , as well as 

 the many uses o£ oxidizing agents in the production of phenol pig- 

 ments, suggested that 'atmospheric oxygen takes an active part in the 

 process. This supposition was confirmed. A current of hydrogen 

 passed throiigh an aqneous ammonia-thymol mixture inhibited the 

 f ormation of pigment. Nascent hydrogen ( f ormed by the addition of 

 Zn dust or sodium amalgam) acted similarly. On the other band, 

 the addition of a few drops of hydrogen peroxid greatly accelerated 

 the production of pigment by oxidation. A rise has been noticed 

 in an aqueous ammonia-thymol mixture inverted over water, in- 

 d'icating the absorption of oxygen. 



The addition of Zn dust to the blue Solution in an open vessel 

 caused the color to disappear, except near the surface, where blue 

 always remained, showing the influence of atmospheric oxygen. 

 Ether was added to ascertain whether the reduced substance could 

 be extracted by it and whether the chromogen thus removed by ether 

 would yield pigment in the presence of oxygen. The bottle was 

 now tightly stoppered and allowed to stand. Within 24 hours the 

 red ether layer (the blue pigment yields a red Solution in ether) had 

 become colorless. On releasing the stopper the ether Solution be~ 

 came colored again. This was repeated many times with different 

 samples but always with the same result. Attempts have since been 

 made to isolate the reduced product by evaporating the ether Solu- 

 tion in a current of hydrogen, but so f ar without success. The work 

 is in progress. 



61. Influence of uranium nephritis on the excretion of 

 Creatinin, uric acid and chlorids, and the effect of Creatinin in- 

 jections during uranium nephritis. W. M. Kraus. In acute 

 uranium nephritis in dogs, Creatinin was excreted in decreased 

 amounts ; uric acid, in increased amounts. In subacute uranium 

 nephritis, Creatinin was eliminated in decreased amounts ; uric acid 

 and dhlorids, in increased amounts (2 weeks). Creatinin, injected 

 in normal dogs, appears to be excreted " in toto." Creatinin, in- 

 jected during acute uranium nephritis, is not wholly eliminated. 

 Such an injection causes decreased Output of endogenous Creatinin, 



"Liebermann: Ber. d. d. Chem. Gesell., 1874, vii, p. 247; 1875, viii, p. 1649. 



