i2 J. L. ROSEDALE 



mutton 18 % histidine, 2 % non-amino N, while in other cases this observa- 

 tion cannot be made. This may be due, either to incomplete precipitation of 

 the hiistidine by the phosphotungstic acid, or to washing. Work in this con- 

 nection is in progress. 



It is not possible to draw any conclusions from the figures of the mono- 

 amino fraction, which account for about 55 to 60 % of the total N. 



The average percentage of the di-amino N is 35. 



Comparison with former work on the hydrolysis of meat is difficult, because, 

 with the exception of Drummond [1916] on chicken meat, the other figures 

 relate to the method of Kossel, which generally gives lower results than the 

 Van Slyke method. 



The above figures for chicken breast agree in the main with those of 

 Drummond, his total hexone bases N 27-26 being the same as that above. 

 The arginine figures are within 1 % and he records having used the same 

 modification of that process as mentioned above. The figures for histidine 

 and lysine are discordant, Drummond finding 8*45 and 9-81 respectively, 

 while the total N of the mono-amino fraction is 4 % higher than that found 

 by Drummond. 



In order to compare the figures of Osborne and co-workers with the above 

 it is necessary to refer to the percentages not of total N but of actual arginine, 

 histidine and lysine. The figures for arginine are generally constant within 

 1 %, those for histidine are higher than Osborne's, while the lysine figures, 

 owing to the calculation in Van Slyke's method, are dependent on the histidine 

 values. Apart from the arginine values, only the beef of the present sets has 

 given results comparable with those of Osborne, who found 7-5 % arginine, 

 1-8 % histidine and 7-6 % lysine against 6-8 % arginine, 2-6 % histidine and 

 9*6 % lysine in this experiment. 



Summary. 



1. Determinations have been made of the di-amino-acids of the protein of 

 the flesh muscle of rabbit, chicken, ox, horse, sheep, pig by Van Slyke's method. 



2. The red meats show a higher lysine content than the white meats. 



I wish to take this opportunity of expressing my gratitude to Dr Plimmer, 

 who suggested this work, for his kindness and guidance throughout the time 

 I was under him, and also to Professor J. A. Mac William, F.R.S., for so kindly 

 placing his laboratory at my disposal. 



REFERENCES. 



Drummond (1916). Biochem. J. 10, 473. 



Gortner-Holm (1920, 1). J. Amer. Chem. Soc. 42, 821. 



Gortner-Holm (1920, 2). J. Amer. Chem. Soc. 42, 1682. 



Osborne and Heyl (1908). J. Biol. Chem. 22, 433; 23, 81. 



Osborne and Jones (1909). J. Biol. Chem. 24, 161, 437. 



Plimmer (1916). Biochem. J. 10, 115. 



Plimmer (1921, 1). Analyses and Energy Values of Foods (Stationery Oflfice). 



Plimmer (1921, 2). Proc. Roy. Inst.; Nature, 107, 664; J. Soc. Chem. Ind. 40, 227. 



Thomas (1921). Bui. Soc. Chim. Biol. 3, 197. 



