[o66 



PROTEIN METABOLISM 



[PT. in 



parts of the egg from time to time, and it will be convenient at this 

 point to consider what knowledge their work has led to. Albumoses 

 and peptones have been shown to be present in the egg-white by 

 qualitative analysis on the 15th day by Fischel and on the 6th by 

 Emrys-Roberts. One of the first of these investigators was Tomita, 

 who removed the proteins from the white and the yolk by boiling with 



Non-protein nitrogen 

 ©Total non-protein nitrogen \ ©Total non-protein nitrogen | 



© Non-protein nitrogen pre- I Non-protein nitrogen pre- iNaka- 



cipibable with phosphotungsbic acid>Tomita cipi table with phosphotungstlc acid imufa 

 O Non-protein nitrogen not yQ— D Non-protein nitrogen not precipitablej 



precipitable 

 ®Total non-protein nitrogen (Aggazzotti) 

 ♦ " " » " (Vladimirov Sc 



Sclimidt^gQ 



13 Total non-protein 

 nitrogen (Wright) 



Days-* 5 



Days- 



Fig. 301. 



acetic and precipitating with tannic acid, after which he estimated the 

 total non-protein nitrogen in the filtrates, the nitrogen precipitable 

 by phosphotungstic acid (the di-amino-acids, peptides, and some of 

 the cystine), and, finally, that not so precipitable (the mono-amino- 

 acids, and some of the cystine and arginine) . His results are shown 

 in Fig. 301, together with those of Nakamura, who later confirmed 

 him. Unfortunately neither of them took into account the varying 

 water-content of the white and the yolk, so that the rise found in 



