46 
M. PASTEUR. 
life of the inoculated microbe which gives rise to the abscess, 
which becomes, for the small organism, as a closed vase where it 
is easy to obtain it, even without killing the animal. It keeps 
there, mixed with the pus, in a great state of purity and with¬ 
out losing its vitality. The proof of it is that, if one inoculates 
chickens with a little of the contents of the abscess, these chick¬ 
ens die rapidly, while the Guinea-pig, which has furnished the 
virus, gets well without the slightest suffering. One sees, then, a 
localized evolution of a microscopic organism which stimulates the 
formation of pus and of a closed abscess, without producing in¬ 
ternal disorder, nor the death of the animal upon which it is met, 
and always ready at least to carry death to other species to which 
it is inoculated ; always ready even to kill the animal in which it 
exists in the state of abscess, if such circumstances more or less 
fortuitous, cause it to pass in the blood or in splanchnic cavities. 
Chickens or rabbits living with guinea-pigs having such abscesses 
might become suddenly sick and die, and still the health of the 
guinea-pigs seem to remain perfect. For this it would be suf¬ 
ficient that the abscesses of the guinea-pigs, ulcerating, should 
throw a little of their contents on the food of the chickens and 
rabbits. Witnessing these facts, and ignorant of the connections 
I am relating, an observer would be surprised at the death of the 
chickens and rabbits without apparent cause, and would refer it 
to the spontaneity of the disease; as he might not believe that it 
would have started from the Guinea-pigs, ail in good health, and 
especially if he knew that this specie of animals is, itself, subject 
to that disease. How many mysteries in the history of contagions 
will one day receive solutions still more simple than the one 
I am speaking of!! Let us throw aside the theories, that we can 
contradict by positive facts, but not by the vain pretext that some 
of their applications escape us. The combinations of nature are 
at all times singular and more varied than those which meet the 
ordinary conceptions of our minds. 
One will be better convinced of what I say, if I add that sev¬ 
eral drops of a culture of our microbe, placed on bread or on 
meat which chickens will eat, are sufficient to introduce the dis¬ 
ease by the intestinal canal, where the little microscopical organ- 
