134 
M. L. PASTEUR 
inoculated muscle is enormously swollen, lardaceous in its thick¬ 
ness, and filled with the parasites. The mortality commences. 
One dies, then another, until, in forty-eight hours, all are dead. 
Again, twenty others are vaccinated to the maximum , inocu¬ 
lated at the same hour as the others, at the same place, with the 
same virus and the same quantity. The next day, and the day 
following, all are active and alert; they eat, cluck ; the rooster 
crows ; it is the movement and life of perfect health, and the 
muscles of the thigh present no abnormal appearance. Often, 
even the mark of the inoculation cannot be seen, and this state of 
health continues, precisely as if no vaccination had been per¬ 
formed. 
But is not this impossibility of culture of the parasite in the 
muscles confined to those muscles which have received the inocu¬ 
lations of prevention ? It becomes, then, important to ascertain 
what would happen if the deadly virus was introduced either by 
the circulatory or digestive apparatus. I took ten hens, virgin 
from any inoculations, and ten others vacinated to the maximum ; 
in all the most virulent lymph was injected in the jugular. The 
first ten died rapidly, several of them in twenty-four hours. On 
the contrary, the other ten recovered, without having suffered any 
appreciable sickness, aside from the results of the incision in the 
skin and jugular. The blood then was itself vaccinated , if it is 
proper so to express it—that is, the preventative culture had 
taken from it its materials of culture for the microbe. 
And what would be the consequences of the introduction of 
the disease into the digestive canals ? Let us try to produce an 
epizootic analogous to that which affect poultry-yards, by the food 
contaminated by the presence of the parasite. On the 11th of 
March, I put together twelve hens, bought in the market in the 
morning, with twelve others, previously inoculated to the maxi¬ 
mum. Every day, I give to those twenty-four hens a meal of 
diseased muscles from a hen dead by the microbe. The following 
days the disease and mortality are observed amongst the twelve 
non-vaccinated birds, distinguished from the others, as those have 
had a platinum wire run through their combs. On the 26th of 
March, the experiment is stopped. Seven of the non-vaccinated 
