MICROSCOPICAL EXAMINATION OF FLOUR. 11 



Table 8. — Effect of method of computing average on count. 





Bran particles. 



Hairs. 



Method of averaging. 



Keenan. 



Lyons. 



Keenan. 



Lyons. 





Min. 



Max. 



Min. 



Max. 



Min. 



Max. 



Min. 



Max. 





20 

 22 

 22 

 23 



43 

 40 

 39 

 39 



19 



20 

 21 

 21 



43 

 42 

 41 

 41 



48 

 47 

 49 

 51 



80 

 79 

 79 



77 



49 

 48 

 49 

 50 



83 





81 





81 





80 







EXAMINATION OF MILL STOCKS. 1 



Before undertaking a discussion of the work done on finished com- 

 mercial flours, it seemed advisable to consider the degree of purity of 

 the various mill stocks entering into the composition of the end- 

 product. The data compiled in Table 9 demonstrate the quality of 

 the stocks made on the break rolls, the purpose of which is to crush 

 the wheat kernel to release the enclosed endosperm that is later re- 

 duced to fineness on other rolls and finally purified of offal debris. 

 The general practice in milling is to make as little break flour as possi- 

 ble. When break flour is made to any extent, it invariably con- 

 tains a notable amount of offal, consisting of bran particles, as well 

 as numerous hairs from the beard. The results recorded in Table 9 

 were obtained on samples of material procured from the first, second, 

 third, and fourth brejak rolls, respectively, and from different mills. 

 It was stated that they had been bolted through silks of various 

 numbers of meshes per lineal inch, the following silks being employed: 



Silk number. 



Meshes 

 per inch. 



lOxx 



109 

 116 

 125 

 125 

 125 

 129 

 139 



llxx 



12xx 



12x 





13xx 







1 The designations for the various stocks and grades of flour examined, as well as the statements concern- 

 ing the kind of wheat from which the flour was milled, were taken from the millers supplying the samples 

 and were not verified in the Bureau of Chemistry. 



