UPON VIRULENT DISEASES-!—CHICKEN CHOLERA. 
51. 
will give rise, the first principally, to such great alteration of 
the muscle that large sequestra will be felt under the fingers. 
The cause of the difference in the effects of these inoculations 
seems to reside entirely in a great relative facility of the develop¬ 
ment of the microbe after the first inoculations, and for the last, 
on the contrary, in a non-development* or in a very weak one, 
rapidly stopped. The consequence of these facts is manifest; 
the muscle which has been diseased has become after its recovery 
and its repair* unable fully to cultivate the microbe, as if this last 
by an anterior culture had removed from the muscle some prin¬ 
ciple that is not returned by life, and whose absence prevents the 
development of the little organism. In my mind, this explana¬ 
tion, to which we are brought by most palpable facts, will become 
probably general and applicable to all virulent diseases. 
The explanation that I have given of the protection against a 
second attack of cholera will seem so much more plausible that, 
if, after three or four days of culture nf the microbe in a» liquid 
medium, this last is filtrated to a perfect limped state, and if it is 
then sowed again after several days of proof of its limpidity at a 1 
temperature of 30 degrees, all cultivation remains impossible. 
Still the weight of the microbe, formerly developed, was impon¬ 
derable. Remarkable fact, this filtrated, and thus sterile, liquid 
is far from retaining this sterility towards other microscopic or¬ 
ganisms : for instance, it grows the carbuncular bacteridfe,' and 
this allows us to comprehend why an organism in which a viru¬ 
lent disease does not recidivate, is nevertheless liable to contract 
a virulent disease of another nature. It would be easy to give 1 
anthrax to hens vaccinated for chicken cholera. 
It would seem to me superfluous to show the principal con¬ 
sequences of the facts I have just presented.' There are two 
however, which it may not be without utility to mention. First 
is the hope of obtaining artificial cultures of all the virus ; and 
again, a desire to search the vaccine virus of the virulent dis¬ 
eases which so often have desolated, and again every day desolate 
humanity, and which are such a great curse to agriculture in the 
raising of domestic animals. 
