179 
search of the literature failed to show that this idea of giving an 
amount of tuberculin sufficient to cause the death of a tubercular 
animal as a means of differentiating true tuberculosis from infection 
with other acid- fast organisms had ever been used by previous work- 
ers. The febrile reaction in a sick guinea pig on account of the great 
variation in the temperature of the animal from handling, etc., is too 
variable a factor, and a more definite reaction, such as the death of 
the animal, is necessary. The technic was as follows: All of the 
animals, in lots 'of about 30, were given early in the morning 2 cubic 
centimeters of the tuberculin subcutaneously ; they were closely 
watched and as soon as an animal appeared sick it was placed aside: 
as soon after death as possible the animal was autopsied; smears, 
cultures, and sections were made. Of all the guinea pigs, about 250. 
that received the tuberculin, no animal that did not have tuberculosis 
died. Two or three that had slight lesions did not die, but became 
sick. It was noted that all of the animals died whose lesions had 
caseated. The reaction, I think, was of distinct service in eliminat- 
ing infections with other acid-fast organisms. The suggestion is 
made that with some modification the procedure may have a distinct 
place as an aid in differentiating true tuberculosis from infections 
with other acid-fast organisms which produce tubercular-like lesions. 
Samples of milk were examined from 101 different dairies; 10 
samples from 7 hospitals and asylums are also included in this num- 
ber, they being charged also to the daily supplying the milk. 
The following tables show the laboratory number of the dairy, 
where collected, date of collection, whether the guinea pig inoculated 
died or was killed, interval between inoculation and death, and results 
of the autopsy. 
It is interesting to note that where 2 guinea pigs were inoculated 
with the same sample of milk, in two instances both animals showed 
tuberculosis and in two instances only one Tvas positive : 
TABLE No. 1. 
j No. of guinea 
Pig- 
Weight. 
Date of, 
inocu- 
lation. 
Source. 
Dairy. 
Result. 
Days 
since 
in- 
ocu- 
lated. 
Autopsy. 
Tubercle 
bacilli, 
Pres- 
ent. 
Ab- 
sent. 
44 
July 22 
Wagon 
No. i.. . 
Died . . . 
20 
No evidence of tubercle. 
132 
Aug. 5 
Dairy. 
....do.. . 
do. . 
2 
230 
Aug. 19 
do 
do . . . 
Killed . 
72 
Negative 
231 
do 
do 
. . .do . . . 
Died . . . 
4 
14 
July 15 
No. 2. .. 
Killed . 
101 
Negative 
100 
July 30 
Providence Hos- 
do 
.do. . 
86 
do 
pital. 
101 
do 
do 
do 
Died. . . 
27 
No evidence of tubercle. 
329 
Aug. 30 
do 
....do... 
Killed . 
63 
Negative 1 
