CONTRIBUTION’ TO THE STUDY OF SWINE PLAGUE, ETC. 425 
ist.—In general, the blood and cultures of swine plague and 
of hog cholera that I have used have given manifestations of 
intoxication in the rabbit starting from a dose of \ cc. upward. 
2d.—The phenomena of intoxication are of three orders: 
(a) —Acute intoxication and death in from 24 to 48 hours, 
with symptoms analogous to those obtained with injections of 
virulent cultures. 
(b) — Chronic intoxication, followed with reduction in flesh 
and cachexia, ending by death in a length of time varying 
from between a few days to one and two months; at post 
mortem no lesions, only a very small spleen. 
(e) —Chronic intoxication, followed by the return of the 
animal to health after a variable length of time. 
3d.—Weak doses to 1 cc. are ordinarily well tolerated with¬ 
out giving rise to any noticeable troubles. 
4th.—1 have not been able to observe that rabbits become 
accustomed to toxine ; rabbits that had received several injec¬ 
tions of small quantities of toxine reduced in weight when the 
dose was increased. 
5th.—The blood of animals dead by an injection of one of 
the microbes sterilized by heat and by thymic acid is more 
toxic than equal quantities of sterilized cultures. 
6th.—Cultures filtrated with the Pasteur bougie, or heated 
for a few minutes to no° or 120°, do not lose their toxic ac¬ 
tion, but bring on symptoms analogous to those produced by 
cultures heated to 58 0 . 
7th.—The properties of toxines do not allow the differen¬ 
tiation of hog cholera and swine plague. 
VACCINATION AGAINST SWINE PLAGUE AND AGAINST HOG 
CHOLERA. 
Animals that have resisted to several injections of toxine 
have shown themselves refractory to the inoculation of the 
viruses. 
For swine plague I have succeeded in vaccinating rabbits 
by several ways, viz., by repeated injections of— 
ls t.—Blood sterilized by heat (58 to 6o°) or by thymic acid. 
2 d.—Cultures sterilized by heat (58 to 6o°). 
