394 
M. ARLOING, CORNET IN AND THOMAS. 
To-day we desire to call attention to a new way to reach the 
same result, by injecting under the skin attenuated virus. 
a _The mode of attenuation which we have regulated and 
applied was suggested by the works of Mr. Toussamt upon the 
bacteridie of splenic apoplexy (sang de rate) which have been 
reconsidered lately, with brilliant success, by M. Chauveau. in¬ 
deed, it consists in the action of heat upon the virulent serosity 
taken from carbuncular tumors; only, this serosity is first dried 
at the temperature of 32° in a current of air sufficient to obtain 
the desiccation before the beginning of putrefaction. 
A long series of experiments has shown us that in triturating 
a certain quantity of virus, dried in the above named condition, 
with twice its weight of water, so as to evenly hydrate all the 
particles and in carrying off these mixtures in an oven heated 
from 85° to 100°, where they are left for six hours, a series of 
virus, attenuated at various degrees, is obtained. It is important 
to attenuate only a small quantity of virus at once, and to regu¬ 
late the heat of the oven in such a way that its initial tempera¬ 
ture may be re-established in less than two hours after the intro¬ 
duction of the virus. 
I _When if is desired to employ the virus attenuated by this 
process, a choice must be established, basefl upon their activity 
and the specific or individual susceptibility of the subjects upon 
which they are to be used; and to fix the dose for a subject ac¬ 
cordingly. The dose has, indeed, a great influence upon the result. 
Thus one may produce a slight disease and vaccinates; anothei, 
and stronger, may give rise to a fatal tumor in which the microbs 
regain all their activity. 
After some hesitation, we have adopted the following practice : 
We make two inoculations, six or eight days apart, the first with 
virus attenuated by a temperature of 100° ; the second with a 
virus heated at 85°. The use of the less attenuated virus might 
be followed by failures, even upon cattle. I or sheep, we take 
0 gr. 01 of each virus in a dry state; for cattle, from 0 gi. 02 to 
0 gr. 03, according to the size. These doses are mixed with one 
hundred times their weight of water aud crushed in a moitai 
'until a mass suitable to be injected under the skm is obtained. 
