438 Pht/sical Characteristics and Milfin// Qualitu 



which have the larger proportion of bran and germ, also have the lower 

 specific gravity. This is shown by Table III, which gives the specific 



gravity of a number of lianl red spring wheat samples arranged according 

 to their size or kernel vohimo. Deviations from the general rule 

 exhibited by certain of these sam])les may be explained on the basi.s 

 of their nitrogen content, as will be shown later. Thus C 783 in the 

 first group has a specific gravity of 1-4083, which is somewhat above 

 the average of similar samples so far as kernel volume is concerned. 

 It contains 2-62 per cent, of nitrogen, however, which is considerably 

 more than is found in the others in the group. Similarly the average 

 specific gravity of the entire second group, in which the kernel volumes 

 range between 12 and 14 c.c. per 1000, is probably somewhat high 

 because of the higher average nitrogen content. The data indicate 

 that the bran and germ tissues have a lower specific gravity than do 

 the endosperm structures, which fact must be considered in evaluating 

 wheats on the basis of specific gravity. 



Practical fU)ur milleis have observed that in general the milling of 

 the soft types of wheat by tiu' roller jirocess presents greater diflieulties 

 than does the milling of hard kinds of the same degree of plumpness. 



