of the University of Pennsylvania. 49 



conclusively proven that nitrogen in non-albuminoid 

 combination i.e., in compounds not capable of afford- 

 ing nourishment to any of the higher organisms is 

 present in many food -stuffs, and especially in those 

 of vegetable origin. As a case in point may be 

 mentioned the analysis of AVigner, 1 in which it is 

 shown that of the total nitrogenous matter of the 

 entire wheat-grain, 87.9 per cent, is coagulable, 

 i.e., distinctively proteid. Of the bran only 42.4 per 

 cent, of its nitrogenous compounds are coagulable, 

 whereas, in the flour, 89.7 per cent, of these bodies 

 come under the head of true proteids. Yet more 

 marked instances of the inaccuracies attending the 

 ordinary methods of estimating proteids have be- 

 come evident in the course of researches by Schulze 

 and Barbieri, 2 who find that of the entire nitrogen 

 of the potato but 56.2 per cent, enters into the com- 

 position of albuminoid matter, while in the fodder- 

 beet only 20 per cent, of its contained nitrogen is 

 thus combined, the remaining 80 per cent, aiding in 

 the formation of amides, nitrates, and ammonia. It 

 is evident from these facts that estimates of the nu- 



1 Der oeslerr. ungar. Miiller, 1879, p. 52. 



2 Quoted by Voit, Hermann's Hdb. d. Physiol., vol. vi. p. 



462. 



5 



