34 



Scientific Proceedings (78). 



The conclusion, therefore, seems reasonable that tartaric acid 

 and oxalic acid exert their influence on the kidney tubules by 

 precipitating the calcium salts in the cells, during the process of 

 their excretion. 



22 (1200) 



Do lecithin and glucose combine to form a true chemical 

 compound? 



By Ernest L. Scott. 



[From the Department of Physiology, Columbia University, New 



York.} 



About a year ago I 1 reported a substance found after the 

 evaporation of an emulsion of lecithin and glucose. This material 

 seemed to be identical with the one previously reported by Bing 2 

 and others, the only point of difference being that previously it 

 had been prepared by the evaporation of an alcoholic solution of 

 lecithin and glucose upon the water bath while I evaporated 

 a watery emulsion either on the water bath or in a vacuum 

 desiccator at room temperature. 



In attempting to study by the freezing-point method any 

 changes in molecular weight which might occur, I found that 

 some reaction took place between the benzene, which was used 

 as a solvent, and the solute, lecithin, so that the results were 

 entirely irregular and of no value for my purpose. 



A further search for a solvent which could be used for the 

 determination of either the freezing or the boiling point has re- 

 vealed the same difficulty for a number of other solvents. In 

 their turn ether, chloroform, carbon tetrachloride, bromoform, 

 ethylene dibromide, acetic acid, formic acid and phenol were 

 tried and discarded. 



However, when the boiling point of a solution of "lecithin" 

 in alcohol was determined the molecular weight of the sample of 

 "lecithin" which I was using was consistently found to be 1,300. 

 The high figure found would indicate an association of two mole- 



1 Scott, E. L., Am. Journ. of Physiol., XL. p. 145, 1916. 



2 Bing, H. J., Skand. Arch. f. Physiol., XI, pp. 166-175, 1901. 



