90 



OUR FARM CROPS. 



tions of sugar, gum, and oil, all severally subserve the 

 purposes of nutrition, and give to wheat the high feeding 

 value universally assigned to it. The proportion of starch 

 is about 50 to 60 per cent. ; the gluten may be taken at 

 1 2 per cent. ; and the other substances together at from 

 8 to 10 per cent. Thus, we may take the average com- 

 position of the grain of wheat to be 



Water about 12 in the 100 parts. 



12 

 55 

 12 



Bran 



Starch 

 Gluten 

 Oil ) 

 Sugar [ 

 Gum ) 



In grinding, the bran is never entirely separated, and 

 that portion which is separated always carries with it a 

 certain proportion of flour sometimes in sufficient quan- 

 tity to pay for a subsequent process of separation. Pro- 

 fessor Johnston gives, as the results of three lots of good 

 wheat ground for him in Durham 1 



The bran itself, irrespective of the proportion of flour 

 always attached to it, has a high nutritive value, though 

 probably owing to the shape which its constituents assume 

 to fit them for the duty they have to perform as the "testa" 

 or seed coat of the grain they are not so readily digested 

 and assimilated as the other portions of the grain. There 



1 Johnston's Agricultural Chemistry and Geology, p. 864. 



