475 
Table No. 16. 
[The milk was brought to the laboratory and inoculated with the cultures two hours after 
milking. The time given, however, is from the hour of inoculation. When obtained, 
the whole milk contained 1,200 bacteria per cubic centimeter. The sediment, rich in 
leucocytes, contained 630 bacteria per cubic centimeter, and the milk serum 490. The 
milk was revolved in a centrifuge at 1,500 revolutions for twenty minutes ; the sediment 
pipetted off was rich in leucocytes. The supernatant serum was drawn off and filtered 
three times through asbestos and was therefore free of leucocytes. The milk was 
inoculated with a pure culture of B. lactis aerogenes and B. typhosus. Four test tubes 
were prepared with each culture, (1) whole milk, (2) the sediment i*ich in leucoytes, 
(3) the milk serum containing no leucocytes, and (4) sterilized whole milk used as a 
control.] 
Bacteria 
per loop, 
at once 
after in- 
ocula- 
tion. 
Bacteria per loop after — 
3 hours 
at 37° C. 
6 hours 
at 37° C. 
9 hours 
at 37° C. 
B. lactis aerogenes: 
Whole milk 
1,500 
30 
2 
46 
Sediment, rich in leucocytes 
1,200 
31 
5 
34 
Milk serum, no leucocytes 
1,400 
52 
8 
370 
Control, sterilized millr 
1,300 
25,000 
200, 000 
(a) 
B. typhosus: 
Whole milk 
7,200 
5,000 
1,500 
1,700 
Sediment, rich in leucocytes 
6, 100 
2,400 
2, 300 
1,600 
Milk serum, no leucocytes 
4,200 
2, 800 
3, 900 
14, 000 
Control, sterilized milk 
3,700 
15, 000 
67, 000 
(o) 
a Innumerable. 
The milk in both of these experiments was obtained from a healthy 
cow (No. 2) in a cleanly manner, but without special precautions. 
The tables give the number of bacteria per loop on agar, grown at 
37° C. and counted after twenty-four hours. 
These tables eliminate the leucocytes and phagocytosis as a material 
factor in the problem we are studying. 
IS THE GERMICIDAL ACTION SPECIFIC? 
Almost all those who have studied this part of the problem con- 
clude that the germicidal action of milk is specific. The following 
experiment confirms these observations. Here we have the same 
milk showing an active power of restraining the growth of typhoid 
and staphylococcus pyogenes aureus, but not paratyphoid A or B. 
Reference to our work upon the influence of heat (vide infra) upon 
this property of milk also indicates its specific nature. 
The table again demonstrates that agglutination plays at least 
some part in the apparent decrease. 
