308 
M. H. TOUS8AINT 
to pigeons, it killed them first in four or live days, then in three, 
again in two or in one day. Inoculated from the pigeons to the 
hens, the same results were obtained, to wit, that the first hen 
died in four or five days, and the others successively in three, in 
two and in one. In making these experiments I was careful to 
compare the lesions of chicken cholera with those resulting from 
inoculation. I had asked M. Parteur to send me the microbe of 
that disease, and I am constrained to say that the closest observa¬ 
tions failed to establish any difference in the symptoms, the 
lesions of the skin, of the muscles and of the blood, nor in the 
cultures of these parasites. These experiments were made in dif¬ 
ferent places and with special instruments for each case. 
I then inoculated directly to hens the blood of the rabbits 
killed by speticaemia. The result was an attenuated virus, slight 
lesions of the skin and connective tissues underneath ; sometimes 
slight alterations of the muscular fibres, but the hens in all the 
cases recovered, and became refractory to the cholera. The cul¬ 
tures of the blood of septicaemic rabbits act in the same manner. 
In this case the inoculation merely produces in hens a slight 
cicatrix of the skin, round and regular. 
With this variety of septicaemia of the rabbit, which has no re¬ 
lation to that described by M. Pasteur, Joubert and Chamberlain 
in a previous note, a practical vaccine might be made which 
would greatly tend to arrest our most serious epizootics. A 
single inoculation in the tip of the tail would be all that is re¬ 
quired in order to avoid depreciation in value. When septicaemia 
has killed the hen, after passing through the pigeon, its excessively 
violent properties, in reference to those two species, are pre¬ 
served, even after inoculation to the rabbit. 
The determining causes of epizootics in chicken cholera are yet 
unknown. It has been supposed that putrefying substances might 
give rise to it; hence the adoption of measures of cleanliness and 
disinfection which have been recommended. The microbe which 
killed the first hen in an epizootic has certainly come from an 
anterior generation which had killed others; but how was it per¬ 
petuated ? Do not the facts which demonstrate the development 
of septicaemia in putrid matter throw some light on that etiology { 
