6 
THE AGRICULTURAL EXPERIMENT STATION. 
Accuracy .—The accuracy of the Babcock was tested by 
the gravimetric method—it is true by samples taken from 
ten to twelve hours apart, but under the most favorable con¬ 
ditions of the milk possible, with that consideration. The 
variations below, though small, would not likely be as 
much if the samples where taken at the same time. 
Source of Sample. 
Averages of 
Per Cent. Butter Fat. 
Gravimetric. 
' 
Babcock. 
Difference. 
Shorthorn cow. 
7 samples in Feb. 
4.14 
3.86 
.28 
Shorthorn cow. 
7 samples in Feb. 
3.98 
3.28 
.70 
Jersey cow. 
7 samples in Feb. 
3.07 
2.94 
.13 
Jersey cow. 
7 samples in Feb. 
4.00 
4.04 
—.04 
Shorthorn cow. 
8 samples in March. 
4.01 
3.83 
.18 
Shorthorn cow. 
8 samples in March. 
3.60 
3.30 
.30 
Jersey cow. 
8 samples in March. 
3.10 
2.82 
.28 
Jersey cow. 
8 samples in March. 
4.05 
4.17 
— .12 
Accuracy depends gnainly on the careful sampling of 
the milk, using reagents of the proper strength, and in 
following directions closely. It is seldom, if ever, that 
the graduated scales on the test bottles are wrong. By 
several trials with all in duplicate an error can easily he 
discovered. 
After testing the Babcock with the gravimetric, we 
then tested the Cochran, Shorts and Babcock together, 
with the following results, which can be said to be very 
little better for one than another: 
