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HERMANN M. BIGGS. 
ness, which settles to the bottom on the fourth day. This deposit, 
when used for the inoculation of sound animals, produces in some 
instances a rabies which is very characteristic, excepting that the 
duration of the incubation period is much more prolonged than 
that following the employment of the virus which served for the 
original inoculation. ” 
As a cultivation medium, a brain broth was used, usually that 
from sheep, as fresh as possible, and triturated with a little 
sterilized water and carbonate of potassium. The liquid, filtered 
at first through paper, is then passed through a Chamberland 
filter, and after this remains perfectly clear if all the operations 
have been carried on with sufficient care. 
The method of trephining is not used, as being too complica¬ 
ted. The virulent liquid is injected by a pointed cannula carried 
along the conjunctiva to the bottom of the orbit, which is then 
made to pierce the lamella of bone which separates the base of 
the brain from the orbit. This method, according to Fol, has 
succeeded well, and is easy of application. 
If a portion of the deposit which the cultivations present 
after four days is placed on a cover-glass, dried, and treated with 
the hardening solution, composed of bichromate of potassium 
and sulphate of copper, and is then colored and decolorized in the 
same manner as the sections of the cords, the same groups of 
micrococci are presented, and they have the same deep violet 
color. Rabies did not follow inoculations with cultivations 
more than six days old. He says: “It would be interesting to 
know whether this depends upon an attenuation of the virus, 
and whether the inoculated animals thus become refractory to 
rabies.” 
Pasteur had before described the presence of certain granules 
in rabid marrows; but Fol says: “In the want of precise 
descriptions, it is not possible for us to decide whether they are 
identical with the microbe which we have succeeded in coloring 
and cultivating. And as for the brilliant granules described by 
M. Gibier, they appear to be much larger than this microbe, 
which is not visible with a magnifying power of five hundred or 
six hundred diameters.” 
