Hydrolecithin. 



31 



126 (1304) 



Differentiation of typhoid, paratyphoid A and B by means of a 

 dextrin-inosite medium. 



By^FLORENCE Hulton-Frankel and Katherine MacDonald 



(by invitation). 



[From Harriman Research Laboratory, Roosevelt Hospital.] 



Typhoid and paratyphoid A and B can be differentiated by 

 means of a medium consisting of a 3 per cent, agar containing 

 1 per cent, of inosite and I per cent, dextrin, using litmus as an 

 indicator. The dextrin must be one of the lower dextrins. The 

 typhoid ferments the dextrin with acid formation in the butt of 

 the tube, decolorizing entirely in 24 hours with a violet slant. 

 Paratyphoid A does not ferment either dextrin or inosite and so 

 the butt and slant of tube both remain violet in color. Para- 

 typhoid B ferments inosite with gas formation and so para- 

 typhoid B decolorizes the butt of the tube with the formation of 

 gas bubbles, while the slant remains violet in color. 



127 (1305) 



Hydrolecithin and its bearing on the constitution of cephalin. 

 By P. A. Levene and C. J. West. 



[From the Rockefeller Institute for Medical Research.] 



The recent investigations on the chemical structure of lecithin 

 have resulted in many important contributions, all of which point 

 to the correctness of the generally accepted view of its molecular 

 structure, 



H 2 C - O - COC 17 H 35 

 I 



HC - O - COC lv H 3 i 

 I 



H 2 C - O - P = O 



/\ OH 

 (HO) x O - CH 2 — CH 2 — N = (CH 3 ) 3 



However, a scrutiny of all the work on lecithin reveals a re- 

 markable incompleteness of each individual investigation. A 



