461 
ject through. The foremilk was discarded and about 10 to 15 cubic 
centimeters of the midmilk was introduced directly into sterile test 
tubes. Some of these tubes, tested soon afterwards, were found to 
be practically sterile; other contained about 60 bacteria per cubic 
centimeter. Without delay, a loopful of a pure culture of the 
organism to be tested from a 24-hour-old agar slant was placed in 
the tubes of the freshly drawn milk. Two of the tubes were con- 
taminated with each culture tested ; one of them was 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 the intervals shown in the tables the tubes were 
shaken in order to obtain a uniform suspension, and a loopful planted 
upon agar by the plate method. Duplicate plates showed that the 
loop always took up about the same quantities. The results, how- 
ever, do not pretend to mathematical accuracy, but are sufficiently 
consistent to show any marked increase or diminution in the number 
of colonies. 
Table No. 4. — B. typhosus. 
Number of bacteria per loop — 
Milk from healthy cow (No. 2). 
At 15° C. 
At 37° C. 
In raw 
milk. 
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 
(a) 
10 hours later 
4,620 
11,000 
480 
(o) 
12 hours later 
3,180 
37,500 
1,800 
(a) 
24 hours later 
48 hours later 
4,200 
(a) 
31,000 
(a) 
(°) - 
(a) 
a Innumerable. 
Here it was plain that there was an actual diminution in the num- 
ber of typhoid colonies 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. 
