10 
BULLETIN 839, U. S. DEPARTMENT OF AGRICULTURE. 
Apparently, sifting or thorough mixing of the flour a number of 
times has little appreciable effect upon the offal count obtained. 
NUMBER OF SLIDES COUNTED. 
In practice, two slides, or at most three, from the sample of flour 
have been used as the basis for judgment as to the character of the 
product as far as the offal material was concerned, and the question 
might very properly be asked if that number is sufficient. In order 
to test out this point, 12 slides were prepared from the same bulk 
sample of flour. Two counts on each slide were made of the bran 
particles and hairs by each of two analysts. The results obtained are 
recorded in Table 7. 
Table 7. — Counts on 12 slides. 
Slide des- 
ignation. 
Analyst. 
Count 
No. 
Bran 
parti- 
cles. 
Hairs. 
Slide des- 
ignation. 
Analyst. 
Count 
No. 
Bran 
parti- 
cles. 
Hairs. 
A 
Keenan 
...do 
Lyons 
do 
1 
2 
1 
2 
1 
2 
1 
2 
1 
2 
1 
2 
1 
2 
1 
2 
1 
2 
1 
2 
1 
2 
1 
2 
21 
22 
20 
22 
24 
23 
19 
23 
23 
31 
34 
33 
33 
30 
31 
35 
24 
22 
23 
26 
31 
29 
29 
30 
76 
75 
78 
77 
54 
53 
52 
56 
55 
60 
59 
53 
77 
81 
84 
82 
79 
79 
82 
78 
64 
65 
70 
66 
G 
Keenan. — 
do 
1 
2 
1 
2 
1 
2 
1 
2 
1 
2 
1 
2 
1 
2 
1 
2 
1 
2 
1 
2 
1 
2 
1 
2 
38 
32 
35 
40 
37 
24 
38 
40 
26 
44 
44 
42 
39 
38 
34 
41 
32 
30 
33 
37 
32 
36 
42 
39 
64 
A 
G 
57 
A 
G 
Lyons 
do 
61 
A 
G 
61 
B 
Keenan 
....do 
H 
Keenan 
...do 
61 
B 
H 
47 
B 
Lyons 
...do 
H 
Lyons 
do 
56 
B 
H 
61 
c 
Keenan 
. do 
I 
Keenan 
...do 
74 
c . 
I 
67 
c 
Lyons 
do 
I 
Lyons 
do 
67 
c .... 
I 
72 
D-... 
Keenan 
do 
J 
50 
D 
J 
.. do 
55 
D 
Lyons 
do 
J 
Lyons 
do 
48 
D 
J 
56 
E 
Keenan 
.. do 
K 
Keenan 
do 
63 
E 
K 
60 
E..... 
Lyons 
do 
K 
Lyons 
do . 
68 
E 
K 
71 
F 
Keenan 
do 
L 1 Keenan 
L ' do 
L Lvons 
47 
F 
49 
F 
Lyons 
do 
47 
F 
L 
do 
51 
From the data in Table 7 it is possible to average Keenan's first 
count on slide A with each count made by him. on each of the other 
slides. By averaging the slides by two, 20 is found to be the lowest 
average and 43 the highest average for bran particles, considering 
Keenan's results only. If the average of counts for three slides 
instead of two is to be taken as the basis for final judgment of the 
product, it is apparent that 22 is the average of the three lowest 
results and 40 the average of the three highest (Keenan's results on 
bran particles). Taking the average of the counts on each of four 
slides gives an average minimum count of 22 and an average maximum 
count of 39. Table 8, based on data obtained from Table 7, has 
been prepared to show the results of such methods of grouping. 
