Attempts to Immunize Against Tuberculosis. 25 
then given a fatal dose of a culture of bovine tuberculosis intra- 
venously. Two control rabbits were given an equal amount of 
the same culture. The controls lived 30 days during which time 
they lost weight and presented a typical tubercular appearance. 
The autopsy showed marked and characteristic lesions of tuber- 
culosis. 
The experimental rabbit lived 39 days and kept in good con- 
dition up to one week before its death and then lost weight rapidly. 
The autopsy showed the same marked and characteristic tuber- 
cular lesions as the controls. 
The fact of the long-continued good physical condition of 
the experimental rabbit encouraged us to repeat this experiment 
with some changes. 
January 8, 1910. Two rabbits were sensitised with 
c.c. each of crude tuberculin which was followed on the twelfth 
inst., by injections of 3 c.c. each of tuberculous rabbit serum. 
This procedure was repeated three times and the serum alone given 
six times. 
The following is the table of injections, all subcutaneous. 
January 8, each 34 c.c. crude tuberculin. 
12, 3 " tuberculous rabbit serum. 
14, M " crude tuberculin. 
17, 3 " tuberculous rabbit serum. 
19, M " crude tuberculin. 
21, s " tuberculous rabbit serum. 
One rabbit died on January 2 1 . The other one received on 
January 24, 34 c.c. crude tuberculin. 
" 26, 5 " tuberculous rabbit serum. 
28, 2^ " 
30, 2Y2 
February 3, 3 c.c. tuberculous rabbit serum. 
7» 5 
A rest of 1 1 days was given the surviving rabbit, and then on 
February 18, 1910, it was given a fatal dose of bovine tubercu- 
losis intravenously. Two control rabbits were given the same 
amount of the bovine tuberculosis culture. 
One control died April 5, the second control died July 11 ; both 
these rabbits showed marked and characteristic tubercular lesions. 
The experimental rabbit died July 17, from pneumonia. 
