44 
M. PASTEUK. 
Though realizing the propriety of a becoming humility in 
presence of these mysteries, I hope that the society will see in 
the facts I have the honor to present, unexpected explanations of 
the problems presented by the study of virulent diseases. 
Sometimes in poultry yards, a fatal disease known as chicken 
cholera makes its appearance. Thus affected, the animal is weak, 
staggering, its wings dropping, its feathers staring. If forced to 
open its eyes, it seems to wake up from a deep sleep, and soon re¬ 
turns to this condition until death takes place in a comatose 
agony, and almost without a struggle. The internal lesions are 
extensive. The disease is produced by a microscopical animal 
which, according to Zundel, had been suspected first by M. Moritz, 
later, better described in 1878 by Perroncito, and as late as 1879 
by Toussaint, who has demonstrated by the culture of the little 
organism in neutralized urine, that it was truly the cause of the 
viruleney of the blood. 
In the study of microscopic-parasitic diseases, the first and 
most useful condition to fulfil is to have a liquid where the in¬ 
fectious organism can be easily cultivated and always without a 
possibility of mixture with other organisms of different species. 
Neutralized urine, with which I was so successful in proving that 
the culture of the bacterid* of Davaine was certainly the virus 
of anthrax, was bad for this double object. But the bouillon of 
muscles of chicken, neutralized by potash and rendered sterile by 
a temperature above 100 degrees (110 to 115 degrees,) forms a 
medium for culture well adapted to the life of the microbe of 
chicken cholera. The facility of the multiplication of the micro¬ 
scopic organisms in this medium is prodigious. In a few hours, 
the clearest bouillon becomes turbid, and is filled with a larger 
number of small bodies, extremities fine, slightly strangulated in 
the middle, so that at first sight they look like isolated points. 
These bodies have no proper movement. In a few days, already 
so small when in the way of multiplication, they increase in num¬ 
ber, and form a multitude of points so reduced in size that the 
liquid of culture, turbid at first, so as to look milky, becomes 
scarcely cloudy by the presence of smaller points, rigorously un¬ 
measurable, so small is their diameter. This microbe certainly 
