PHYSIOLOGICAL PATHOLOGY. 
81 
row, during several weeks, when the putrefaction of a cadaver 
has been prevented by a temperature of 0°xl2° below zero. 
We have found that the pure virus, placed in closely sealed 
tubes, was also preserved, during three weeks, and even a month 
during the heat of summer. 
4. We have again verified the fact that rabid virus may exist 
in the cephalo-rachidean fluid, but that its presence was not con¬ 
stant and even that this liquid could produce rabies when it had a 
limpid appearance, but again, would not give it where it had be¬ 
come opalescent. 
5. We have made many attempts to cultivate the rabid 
virus, both in the cephalo-rachidean fluid, and in other sub¬ 
stances, and even in marrow extracted in a perfect state of purity 
from animals killed while in perfect health, but thus far without 
success. “ Can it be that there is no rabid microbe,” was one 
day queried by our confrere, M. Bouley. “1 can only assure 
you,” I answered, “ that if you present to me a rabid and a 
healthy brain, I shall be able to tell you by microscopic examina¬ 
tion of the substance of the two bulbs, which is diseased and 
which is not.” An immense number of molecular granulations 
are present in both, but those in the rabid bulb are finer and 
more numerous, and suggest the belief of a microbe of an ex¬ 
tremely small size, having neither the form of the bacillus nor 
that of contracted micrococcus; they are simply mere points. 
By one method only have we been able, so far, to isolate these 
granulations from all the other elements of the nervous substance. 
This consists in injecting into the veins of the rabid animal, at 
the moment when asphyxia begins, the virus taken from the bulb 
of another animal which has died from rabies. In a very few 
hours, either because the normal elements of the nervous sub¬ 
stances fix themselves upon the capillaries, or, rather, that the 
blood digests them, there remains in this latter fluid only the in¬ 
finitely small granulations previously mentioned. Besides, in these 
quite peculiar circumstances, they can easily be colored by various 
degrees of aniline. * 
* We have not yet the evident proofs that these granulations are absolutely 
the rabid microbes. We are still investigating this point. 
