104 
O. E. SALMON. 
symptoms of fever in the third experiment did not die until the 
seventh day. The deatli of this animal was due to a bacterial 
meningo-encephalitis—being the usual result of inoculating par¬ 
tially insusceptible sheep with large quantities of virus. It seemed, 
then, that this one animal had acquired a certain degree of im¬ 
munity. 
Iu the fifth experiment, five sheep received about two hundred 
and fifty bacilli each. All recovered after presenting slight and 
transient symptoms of fever. Reinocculated, six weeks later, 
with strong virus, four resisted perfectly, while a single one died. 
In this experiment, the first virus used was taken from a rabbit 
which had been dead several days, though perfectly preserved be¬ 
cause of the cold weather. We know', however, from Pasteur’s 
experiments, that when the bacilli are preserved, either at so high 
or so low a temperature that they cannot form spores, they rapidly 
lose their virulence, and, as in this case the strength of the undilu¬ 
ted virus was not tested, there is some reason to doubt if the 
dilution should receive the entire credit of the results. 
In the same communication, M. Chauveau records an obser¬ 
vation with the virus of charbon symptom atique, which corresponds 
to the black quarter of this country, and is entirely distinct from 
charbon. This virus, though one of the most active known, may 
be injected into the veins in considerable quantity without caus¬ 
ing death ; but a very much smaller dose in the connective tissue 
infallibly destroys cattle and sheep. In December, 1880 , ten 
sheep had been collected, which, from many preventive inocula¬ 
tions with charbon virus, had obtained a very complete degree of 
immunity from this disease. Before receiving their final test, 
they were to have a last preventive inoculation wfith one cubic 
centimeter of liquid extremely rich in bacilli. By mistake this 
liquid was filtered through a cloth that had served in preparing the 
virus of charbon symptomatique. This cloth had been washed, 
but a sufficient quantity of virus remained in it to produce the 
disease in each of the ten sheep. The virulent liquid was drawn 
with a syringe from a high and narrow vessel, so that for each 
animal it came from a different depth. The result was in propor¬ 
tion to this depth, being mildest with the first and most severe 
