459 
centimeters of the midmilk was introduced directly into sterile test 
tubes. Some of these tubes, tested soon afterwards, were found to re- 
main practically sterile; others contained about 60 bacteria per 
cubic centimeter. Without delay, a loopful of a pure culture of the 
organism to be tested from a twenty-four-hour old agar slant was 
placed in the tubes of the freshly drawn milk. Two of the tubes 
were contaminated with each culture tested; one of them kept at 
15° C. and the other at 37° C. 
For a control, a similar loopful of culture was planted in a tube 
of whole milk that had been sterilized fractionally upon three suc- 
cessive days. At intervals all the tubes were shaken in order to 
obtain a uniform suspension, and a loopful planted upon agar. 
Duplicate plates showed that the loop always took up about the 
same quantities. The results, however, do not pretend to mathe- 
matical accuracy, but are sufficiently consistent to show any marked 
increase or diminution in the number of colonies. 
Table No. 4. — B. typhosus. 
Milk from healthy cow (No. 2). 
Number of bacteria per loop— 
At 15° C. At 37° C. 
In raw 
milk, i 
In steril- 
ized 
milk. 
In raw 
milk. 
In steril- 
ized 
milk. 
At once, after milking 
6, 720 
10, 400 
6, 580 
4,860 
2 hours later 
6, 100 
10, 180 
4,300 
6,600 
4 hours later 
5,940 
15,000 
985 
15, 360 
6 hours later 
7,920 
20, 000 
388 
(a) 
8 hours later 
1,860 
20, 000 
62 
(°) 
10 hours later 
4.620 
11,000 
480 
(a) 
12 hours later 
3, 180 
37, 500 
1,800 
(a) 
24 hours later 
4,200 
31, 000 
(a) 
(a) 
48 hours later 
(O) 
(“) 
a Innumerable. 
Here it was plain that there was an actual diminution in the num- 
ber of typhoid tolonies from the tube kept at 37° C. during the first 
eight hours, after which multiplication began. The bacteria in the 
sterilized milk used as a control increased almost from the start. At 
15° C. the restraining effect is similar, but less pronounced and more 
prolonged. 
