Attempts to Immunize Against Tuberculosis. 27 
(One of these rabbits was bitten and died from a resulting 
infection, August 1.) 
These four rabbits with three controls were each given an 
intravenous injection of a lethal dose of bovine tuberculosis on 
July 22, 1910, after an interval of 12 days since the last injection 
of tuberculous rabbit serum. 
These rabbits died and showed marked and characteristic 
lesions upon autopsy except the rabbit which died on August 1, 
as the result of a bite and one that died August 22, and was not 
autopsied. This animal, however, showed physical signs of 
tuberculosis before death. 
The following table shows the time of death of the experi- 
mental rabbits and the controls. 
Controls i — died August 8. _ 
" 2— " " 12. 
" 3— " " 15. 
Experimental rabbits — Tuberculin and Tuberculous rabbit serum. 
i — died August 12. 
2 i_ « « 22 . 
Experimental rabbits — Tuberculous rabbit serum and insoluble residue. 
1 — died from infected bite August 1. 
2 — " August 10. 
In order to test the properties of the products obtained from 
the treatment of the tubercle bacilli according to the directions of 
Dr. Vaughan the following tests were made. 
Some of the soluble portion injected subcutaneously into a 
guinea pig produced the following symptoms: nervousness, chilli- 
ness, weakness in the hind quarters, convulsions and death in 
about 45 minutes. 
Injections of the alcoholic insoluble portion did not cause 
symptoms of any sort. 
A small quantity of this insoluble portion was injected into 
each of three guinea pigs. After three weeks two of these pigs 
were injected intraperitoneally with an emulsion of tubercle 
bacilli, from which the split products had been prepared, with 
the following results. 
Pig No. 1 . After 30 minutes, restlessness followed by weakness 
in the hind legs; violent convulsions followed by extreme fatigue. 
These convulsions continued during the day and the pig died 
finally in a convulsion 6 hours after the injection. 
iNo. 2 had lost a great deal in weight and was undoubtedly tuberculous. 
