80 



SCIENCE. 



[N. S. Vol. XX. No. 498. 



gram. The platinum, therefore, constituted 

 32.7 per cent, of the salt. Cholin platinic 

 chloride contains 31.6 per cent, of platinum. 

 It appears highly probable, however, that some 

 of the platinum salt was decomposed during 

 the concentration of its solution with heat. 

 It is also possible that some of the cholin suf- 

 fered decomposition, or was lost, in the manip- 

 ulations preceding its precipitation with 

 platinic chloride. With these considerations 

 in mind, the foregoing results render it highly 

 probable that the phosphorus is present in some 

 form of licithin, but although these calcula- 

 tions are based on di-stearyl-lecithin, it is cer- 

 tain that this is not the only lecithin present. 

 The fact that lecithin obtained in moderate 

 purity (about 99 per cent.) from the kidney 

 extract promptly blackens with osmic acid, 

 indicates that the oleic acid radicle is present. 

 The recognition of this fact would make but 

 trifling changes in the calculations in this 

 report. 



The foregoing analyses appear to justify the 

 conclusion that one may, at least tentatively, 

 assume the phosphorus content of the extracts 

 obtained to be dependent upon the presence of 

 some form of lecithin. 



Upon this assumption the calculations given 

 in the following table* are based: 



Dog Kidneys. 

 I. 14.93 2.04 53.29 7.95 



Rabbit Kidneys. 

 I. 16.59 2.53 66.06 10.96 f 



* The author presented a large number of data. 

 The table here given shows only a few examples 

 of the many results obtained. 



t 2.24 per cent, of the fresh kidney. 



These analyses demonstrate that even in the 

 kidney, which can not be regarded as one of 

 the fat-depots of the body and which probably 

 plays little, if any, part in the general fat 

 metabolism, the lecithin content must be 

 taken into consideration in any study of the 

 fatty extract. The limited number of the 

 observations here referred to do not justify 

 conclusions bearing upon the question of the 

 nature of the fatty changes met with in the 

 kidney, but it is the author's intention to con- 

 tinue the study of this subject. 



On the Phloridzin Test in Bright' s Disease: 

 P. A. Levene and L. B. Stookey. 

 Investigation of the action of phloridzin in 

 Bright's disease has a theoretical as well as a 

 practical interest. The mechanism of kidney 

 diabetes is as yet imperfectly understood. 

 The original idea that it was due to a change 

 in the permeability of the kidney epithelium 

 has gradually lost support, and instead there 

 is a growing belief in the hypothesis that, in 

 kidney diabetes, the sugar owes its origin to 

 an exaggerated catabolic condition of the 

 kidney. This view was first expressed by one 

 of the authors in 1894. In support of this 

 theory evidence was brought forward to show 

 that in animals with injured kidneys, phloridzin 

 fails to bring about glycosuria, or causes it in 

 less degree than in normal animals. However, 

 it is impossible to injure, by means of drugs 

 or by mechanical interference, only one special 

 part of the kidney. In the course of Bright's 

 disease there are known conditions under 

 which the involvement of either the epithelium 

 or of the glomeruli predominates to a very 

 great extent, and this, of course, enables one 

 to study the seat of the sugar formation within 

 the kidney. The observations of most authors 

 tend to show that when the epithelium of the 

 kidney is injured administration of phloridzin 

 fails to cause glycosuria or does so in very 

 slight degree. 



The authors injected simultaneously phlo- 

 ridzin and methylene blue, and compared the 

 course of the elimination of the dye with that 

 of the sugar. The results of their observa- 

 tions in a general way corroborate the state- 

 ments made by other writers. In acute paren- 

 chymatous Bright's disease sugar fails to 



