MICROSCOPICAL EXAMINATION OF FLOUR. 

 Table 2. — Variation in counting of each analyst. 





Count 

 No. 



Bran particles. 





Hairs. 





Slide. 



Jan. 7, 

 1918. 



Jan. 8, 

 1918. 



Jan. 9, 

 1918. 



Jan. 7, 

 1918. 



Jan. 8, 

 1918. 



Jan. 9, 

 1918. 



A 



Keenan. 

 1 

 2 

 1 

 2 

 1 

 2 



Lyons. 

 1 

 2 

 1 

 2 

 1 

 2 



87 

 92 

 60 

 60 

 87 

 81 



103 

 114 

 86 

 80 

 90 

 87 



76 

 82 

 60 

 49 

 62 

 64 



100 



96 

 85 

 77 

 89 

 83 



80 

 83 

 49 

 53 

 60 

 77 



104 

 106 

 78 

 77 

 86 

 86 



59 

 64 

 60 

 58 

 62 

 74 



58 

 52 

 64 

 58 

 62 

 59 



66 

 69 

 55 

 48 

 66 

 68 



54 

 56 

 52 

 55 

 65 

 62 



65 



A 



66 



B... 



61 



B... 



57 



C 



66 



C 



71 



A 



54 



A 



55 



B 



55 



B 



55 



C 



68 



c 



63 







COUNTING THE SAME SLIDE ON THE SAME DAY BY TWO ANALYSTS. 



The variation between the counts made by two analysts on the 

 same slide on the same day is demonstrated by comparing the daily- 

 averages 1 obtained by each of the two analysts. These data are 

 compiled in Table 3. 



Table 3 . — Variation in counting of two analysts on same day^ 



Date. 



Analyst. 



Bran particles. 



Hairs. 



Slide A. 



Slide B. 



Slide C 



Slide A. 



Slide B. 



Slide C 



1918. 





89 

 108 

 19 

 79 

 98 

 19 

 81 

 105 

 24 



60 

 83 

 23 

 54 

 81 

 27 

 51 

 77 

 26 



84 

 88 

 4 

 63 

 86 

 23 

 68 

 86 

 18 



61 

 55 

 6 

 67 

 55 

 12 

 65 

 54 

 11 



59 

 61 



2 

 51 

 53 



2 

 59 

 55 



4 



63 



Jan. 7 



•{Lyons 



59 







9 







67 



Jan. 8 





62 







5 







63 



Jan. 9 





63 







5 









The table shows an average variation in the count of bran par- 

 ticles of 20, with a range of from 4 to 27. The average variation in 

 the count of hairs was 18, with a range of from 2 to 12. It is evident 

 that the variation between analysts in making the count of bran 

 particles is greater than in making the count on hairs. 



DAILY VARIATION DUE TO CONDITION OP LIGHT, ETC. 



To determine what influence, if any, physical conditions, such as 

 degree of light, have upon the count, it is necessary to first eliminate, 

 as far as possible, the personal variations already considered. This 

 may be accomplished by taking the average of two counts on three 



' By "daily average" is meant the average of two counts made by the same analyst on the same slide 

 on a given day. 



