48 Notes from the Physiological Laboratory 



become detached from the main flake, and are with 

 the greatest difficulty recovered. 



III. Wheat-bran contains a considerable but vary- 

 ing proportion of nitrogenous compounds, averaging, 

 however, about 14 per cent. 1 This fact has per- 

 mitted the continued existence of two widely cred- 

 ited assumptions : (a) That this nitrogen exists in 

 albuminoid combination, or, in other words, is in a 

 nutritious form ; and (6) that the prote'id matter of 

 wheat is contained almost exclusively in specific cor- 

 tical cells of the grain, the so-called " glu ten-eel Is." 



(a) Nearly all the existing estimates of the pro- 

 portion of proteids in food-stuffs are based upon the 

 hypothesis that all of the contained nitrogen is 

 present in some albuminoid combination. The per- 

 centage of nitrogen in a given food is therefore as- 

 certained, multiplied usually by either 6.5 (Pay en) 

 or 6.33 (Ritthauseu) and the result recorded as the 

 percentage of proteid matter. It has lately been 



1 Dempwolf, Ann. d. Chem. u. Pharm., vol. cxl. p. 343. 

 His figures, of interest here, are as follows : The amount of 

 nitrogenous matter in the whole wheat was 14 35 per cent. 

 The amount varied in the different grades of white flour from 

 11.01 to 15.56 per cent. The nitrogenous matter of the two 

 grades of bran made from this wheat was respectively 13.93 

 and 14.06 per cent. 



