Hydrolecithin. 



33 



incomplete state because of this. On the basis of recent work 

 on the hydrolytic products of cephalin a certain structural formula 

 has been assumed. This formula requires an elementary com- 

 position of C = 66.17, H = 10.57, N = 1.88, and P = 4.17. 

 However, all samples analyzed beginning with Thudichum and 

 up to the present by most recent investigators consistently had 

 the average composition of C = 60.00, H = 9.30, N = 1.80, and 

 P = 3.80. 



On the basis of these considerations, one may argue that if 

 cephalin and lecithin both had the composition required for them 

 by the theory, then a mixture of the two should possess practically 

 the same elementary composition as either one of them in the 

 pure state. On the other hand, if lecithin possessed the composi- 

 tion assumed by the theory and cephalin that found empirically, 

 then a mixture containing 80 per cent, of the one and 20 per cent, 

 of the other should possess a carbon content of about 64 per cent. 

 Conversely, if a mixture of the two reduced substances possessed 

 an elementary analysis of C = 65.3, H = 11.20, N = 1.75 and 

 P = 3.85, as was actually found, it would justify the conclusion 

 that both lecithin and cephalin possess the composition assumed 

 for them by the theory. 



The material analyzed by us contained 80 per cent, hydro- 

 lecithin and 20 per cent, of an impurity. It was found that the 

 material yielded on hydrolysis besides the choline also the base 

 aminoethanol which was isolated as the gold chloride salt. Hence 

 it was reasonable to assume that the 20 per cent, of impurity 

 consisted of hydrocephalin. If cephalin had the composition 

 found by experience then a substance consisting of 80 per cent, of 

 hydrolecithin and 20 per cent, of cephalin should have an ele- 

 mentary composition of C = 64.56, H = 10.49, N = 1.75 and 

 P = 3.84. On the other hand if both lecithin and cephalin possess 

 the structure assigned to them by theory then the above mixture 

 of the reduced bodies should have the elementary composition 

 found by experiment. Thus the facts presented in this report 

 furnish evidence in favor of the prevailing theory of the molecular 

 structure of lecithin and of cephalin. They also indicate the 

 method by which the reduced cephalin may eventually be obtained. 

 Efforts in this direction are now in progress. 



