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334 
W. SILBEESOHMIDT. 
PATHOGENIC PROPERTIES OF THE TWO MICROBES. 
Both microbes have proved pathogenic for the rabbit, the 
guinea pig, the mouse and the pigeon. My experiments 
were principally made with rabbits. 
The microbe of swine plague has been very virulent from 
the start. A subcutaneous or intravenous injection of one- 
tenth to one-fortieth cc. of culture killed the rabbit, sure , 
two pigeons died, one in eighteen, the other in thirty-six 
hours after receiving one-half and three-tenths cc. under the 
skin. 
The intravenous injection of one-half cc. of culture or ol 
blood killed the rabbit in five to ten hours ; subcutaneous in¬ 
jections of one-twentieth cc. brought on death m twenty- 
four hours. In no case have rabbits survived the weakest 
dose. 
The virulency of the microbe of hog cholera was less, 
especially in my first experiment. The intravenous or sub¬ 
cutaneous injection of one cc. of culture did kill the rabbit 
only in the space of time varying between thirty-six and 
ninety hours. The pigeon died in two to ten days with that 
same dose of one cc.; in a few cases,they survived weak 
doses, less than half cc., but lost a great deal of flesh. The 
successive passages by rabbit blood did not sensibly increase 
the virulency. The method of Selander succeeds better. I 
have, in injecting the crushed spleen of animals dying of 
hog cholera, after being kept several hours within an eture in 
a flammed glass, killed rabbits in six hours and a half, seven 
hours and a half and eight hours. But, like in swine plague , 
this virulency diminished as soon as I stopped the passages 
with the spleen, and I had to use the same process over sev¬ 
eral times. I thus succeeded in obtaining a virulency almost 
always the same and as great as that of swine plague , espe¬ 
cially in injecting directly into the blood ; one-twentieth and 
one-half cc. injected under the skin would produce death in 
less than twenty-four hours. 
The guinea pig dies in one or two days after an injection 
of one to three-tenths cc. of virulent blood under the skin. 
Swine plague seemed to act a little quicker than hog cholera. 
