DETERMINING QUALITY OF MILK FOR CONDENSERIES. 9 
that showed curdiness after sterilization and shaking, while it would 
have rejected 2 out of 44 that were all right; that is, showed no 
curdiness. The acid test would have rejected 18 of the 46 samples 
showing curdiness after sterilization and shaking, while it would 
have rejected 21 of the 44 that showed no curdiness. 
The following tabulation shows the percentage of satisfactory and 
unsatisfactory milk samples that would have been retained or re- 
jected by the alcohol and acidity tests: 
Alcohol test. Acidity test. 
(Per cent.) (Per cent.) 
Satisfactory milk samples retained 95. 5 52. 3 
Satisfactory milk samples rejected 4. 5 47. 7 
Unsatisfactory milk samples retained 6. 5 60. 9 
Unsatisfactory milk samples rejected 93. 5 39. 1 
Table 2 gives a more concrete comparison of the relative value of 
the alcohol and acid tests in the work done at Grove City, Pa. 
Table 2. — Relative value of alcohol and acidity tests on samples run at Grove 
City, Pa. 
Kind of samples. 
Number 
of sam- 
ples. 
Alcohol test. 
Acidity test. 
Times 
correct. 
Times 
incorrect. 
Times 
correct. 
Times 
incorrect. 
44 
46 
42 
43 
2 
3 
21 
18 
23 
28 
Total 
90 
100 
85 
94.4 
5 
5.6 
39 
43.3 
51 
56.7 
EXPERIMENTS AT CONDENSERIES. 
WORK AT FACTORY A. 
Realizing the importance of trying out the alcohol test under other, 
including commercial, conditions, the work was extended to a con- 
densery, which is designated as Factory A, 2 where considerable diffi- 
culty had been experienced in making an evaporated milk meeting 
the requirements of 26.15 per cent total solids and 8 per cent fat. 
The small laboratory apparatus used in the Grove City work was 
set up in the laboratory of this plant and work of the same nature 
as that done at Grove City carried on. Samples of individual pat- 
rons' milk showing positive or negative reaction with alcohol were 
condensed to bring the product as nearly as possible to 18.15 per cent 
solids not fat, that being the portion of the evaporated milk causing 
the difficulty in sterilization. It was the aim to have the samples 
that were evaporated from raw milk showing no coagulation with 
alcohol slightly above the point of 18.15 per cent solids not fat, and 
2 The assistance of F. B. Evans in the work at this factory is acknowledged. 
