40 Society for Experimental Biology and Medicine. 



Extract. Phosphorus. Platinum. Lecithin in the extract (calculated 



Grams. Grams. as distearyliecithin), 



I O.460O I.43 37.23 



O.460O I.47 37.45 



I-5859 O.0650 34.50 



II O.6032 1. 12 29.II 



O.6032 I. II ' 28.99 



2.I556 O.07II 27.4O 



Before incineration, in the first case, the platinum salt in the 

 crucible weighed 0.2009 gm. The platinum, therefore, constituted 

 32.7 <fo of the salt. Cholin platinic chlorid contains 31.6 fo of plat- 

 inum. 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 

 suffered decomposition, or was lost, in the manipulations preceding 

 its precipitation with platinic chlorid. With these considerations 

 in mind, the foregoing results render it highly probable that the 

 phosphorus is present in some form of lecithin, but, although these 

 calculations are based on distearyliecithin, it is certain that this is 

 not the only lecithin present. The fact that lecithin obtained in 

 moderate purity (about 99 fo) from the kidney extract promptly 

 blackens with osmic acid, indicates that the oleic acid radical is 

 present. The recogniton 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 are based the calculations given in the 

 summary at the top of the next page. 



These analytic results demonstrate that even in the kidney, 

 which cannot be regarded as one of the fat depots of the body, and 

 which probably plays little, if any, part in the general fat metab- 

 olism, the lecithin content must be taken into consideration in any 

 study of the fatty extract. The limited number of the observa- 

 tions 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 continue the study of this 

 subject. 



