30 BULLETIN 202, U. S. DEPARTMENT OF AGRICULTURE. 
Table 24. — Alcohol titrations of milk inoculated with pure cultures of bacteria. 
Alcohol titra- 
tion. 
Experi- 
ment. 
Culture. 
Age of 
milk 
culture . 
Acid- 
ity. 
Bacteria 
per cubic 
centimeter. 
90 per 
cent to 
80 per 
cent to 
2c.c.of 
2c.c.of 
milk. 
milk. 
1 
Lactic-acid bac- 
Hours. 
c. c. 
c. c. 
teria 

1.95 
64,000 
3.08 
8.88 
2 
1.95 
2.86 
9.13 
3 
1.90 
"* "131* ,'666' 
3.14 
9.42 
4 
1.95 
120,000 
2.60 
9.52 
5 
1.95 
361,000 
3.05 
9.40 
6 
2.05 
736,000 
3.05 
8.85 
6J 
2.07 
1,660,000 
1.85 
7.08 
Rennet-forming 
bacteria 

2 
1.95 
1.90 
3.12 
3.03 
9.02 
9.52 
" l\'606" 
3 
1.95 
70, 000 
2.50 
9.48 
4 
2.03 
230,000 
2.44 
9.83 
5 
2.04 
2, 850, 000 
3.20 
9.90 
6 
2.04 
9,300,000 
2.80 
8.12 
H 
2.07 
11,100,000 
1.87 
6.18 
2 
Lactic-acid bac- 
teria 

2.00 
25, 000 
184,000 
3.33 
12.55 
2 
2.00 
3.58 
13.82 
3 
2.08 
475, 000 
3.52 
11.18 
4 
2.04 
1,710,000 
3.73 
9.85 
5 
2.18 
4,900,000 
2.00 
7.32 
6 
2.26 
8,400,000 
2.00 
5.50 
7 
2.33 
22,500,000 
1.06 
1.79 
Rennet-forming 
bacteria 

2.00 
6,100 
3.32 
13.95 
2 
2.00 
51,500 
3.40 
13.36 
3 
2.00 
234,000 
3.98 
10.52 
4 
2.00 
1,325,000 
3.57 
9.35 
5 
2.00 
1,300,000 
1.56 
8.98 
6 
2.04 
13,000,000 
1.25 
2.93 
7 
2.20 
21,800,000 
0.83 
1.21 
THE ALIZAROL TEST. 
When the alcohol has alizarin added to it to act as an indicator 
for the acidity the alcohol test is known as the alizarol test. This 
name was given to the test by Morres (21). The use of alizarin as 
an indicator for the acidity of milk has been known for a long time, 
but Morres (19) was probably the first to combine the alcohol and 
alizarin test. He pointed out that the alcohol test was of more value 
than the litmus test and that the combination with alizarin was 
better than the combination of litmus and alcohol. Morres (20) 
used a 68 per cent alcohol with 1.2 grams of fresh alizarin paste, or 
0.4 gram of dry alizarin to 1,000 c. c. of alcohol. Two cubic centi- 
meters of this alizarin- alcohol solution are mixed with 2 c. c. of milk, 
the same as in the alcohol test. This author found that from the 
coagulation by alcohol and the color of the alizarin it was possible 
to obtain a picture of the condition of the milk. According to 
Morres (20) the alizarol test shows the following conditions : 
1. Lilac -red color. (Milk titrated 7° acid.) 
(a) With no coagulation. The milk should keep sweet more than 6 hours. 
(6) With fine flaky coagulation. The beginning of rennet production is shown 
here. 
(c) With heavy flocculent coagulation. This indicates advanced rennet forma- 
tion. 
