CONTRIBUTION TO THE STUDY OF SWINE PLAGUE, ETC. 567 
is also very weak; quantities of 2 and 2.5 c.c. were tolerated 
in intravenous injections without noticeable symptoms; a 
rabbit, which had received 2.75 cc., presented after forty- 
eight hours a diminution in weight of 150 grammes. 
My experiments were not so numerous as for the two 
microbes studied previously. 
It is much easier to vaccinate rabbits against pnemo-en- 
teritis than against swine plague and hog cholera. 
I have obtained this vaccination by repeated injections: 
1st, of small quantities, ^ to 1 cc. of virulent blood more than 
a year old ; 2d, with fresh or aged virulent blood, sterilized 
to the water bath at 58°; 3d, in one case, with injections of 
very small quantities of cultures of blood, both virulent. 
Here are some of the results of these modes of vaccina¬ 
tion : 
No. 238.—ik-q8o ; 3 intravenous injections of aged non-sterilized blood. After 
the third injection of 1.25 cc. great loss in weight (ik-575 the third day). The rab¬ 
bit recovers and stands two trials of injection. 
No. 274.—2k-i5 ; 2 injections of 2.75 cc. and of 2.5 cc. of virulent blood steril¬ 
ized for an hour at 58°. The rabbit supports three trials; the first without wit¬ 
nesses, that of the third dies within 45 hours. 
No. 232.—2k-300 ; five injections ; altogether 8.25 cc of aged sterilized blood. 
The rabbit resists the trial injection and weighs 2k-500 a month later. The witness 
dies with cachexia. 
No. 284.—i8-IV, ik-485 ; injection of one-tenth virulent bouillon culture ; 
large oedema, ear drooping ; on the 27-IV, ik-345 ; the 2I-IV, ik-580 ; second 
injection of 1-40 cc. virulent injection ; the 23-V, ik-800; the i-VI, ik-g6oa third 
injection of one-tenth cc. of virulent blood ; 11-VI, 2k-i35. 
No. 255.—27-III, ik-640 ; subcutaneous injection of 1-20 cc. of bouillon viru¬ 
lent culture ; 28-III, ik-140 ; oedema of the ear ; 31-III, ik-690, still oedema ; 
7-IV, ik-480, oedema smaller, there remains but a large abscess well outlined ; 
14-IV, ik-265 ; 17-IV, ik-120. Dead the 18-IV, in the morning. The blood 
and the cultures remain sterile. 
As can be seen by these, the microbe of the pneumo-en¬ 
teritis of swine which I have used does not differ from the 
two microbes previously studied except by its less virulence 
and the small toxity of its products; it is probable that, as for 
hog cholera, successive transfers by rabbits would have in¬ 
creased its virulency. Cultures offer much less regularity in 
their action as long as the virus has not reached a certain 
intensity. I made the same remark with hog cholera. 
(To be continued .) 
