EXPERIMENTAL PHYSIOLOGY. 
181 
prising if the results had been identical. What must he borne in 
mind from the results obtained by M. Chauveau, is that the method 
of attenuation of viruses by heat has its individuality and impor¬ 
tance, which it will be necessary to take into consideration.— 
Gazette Medicate. 
UPON THE DIMINUTION OF THE YIRULENCY OF THE BACTERI- 
DIE OF ANTHRAX, UNDER THE INFLUENCE OF ANTISEPTIC 
SUBSTANCES. 
By Ch. Chamberland & Roux. 
Phenic acid and bichromate of potassa were used in these ex¬ 
periments. According to the dose of the antiseptic agent, the 
bacteridies lose more or less of their virulent properties, cease to 
produce spores, and die. 
The diminution in the virulency of the bacteridies as thus 
modified is, however, only temporary ; it returns to them by cul¬ 
ture. M. Pasteur has shown that in Toussamt’s method, when 
bacteridies were attenuated by heating for ten minutes at 55°, 
the attenuation was only temporary, their culture continuing viru¬ 
lent. M. Chauveau, in recent experiments, has shown that bac¬ 
teridies deprived of their germs and attenuated by a heat of 45°, 
during two or three hours, would regain their virulency by cul¬ 
ture. Bacteridies attenuated by antiseptics, whether they give 
germs or not, preserve in repeated cultures a diminished viru¬ 
lency. It seems, then, that the varieties of bacteridies thus 
created are so much the more fixed in their new virulent proper 
ties, proportionately as the modifying effect has acted on them 
the more slowly. 
Further experiments authorize the writers to say that other 
antiseptics exercise upon bacteridies an aonalogous action to that 
of phenic acid and bichromate of potassa. At any rate, the dose 
of antiseptic necessary to produce a determined effect varies with 
the Composition of the bouillon of culture. Each variety of bac¬ 
teridies has a special action upon the diverse species of animals. 
For instance, bacteridies reduced by the bichromate of potassa 
can kill sheep, or at least make them very sick (they are then 
vaccinated), while they remain harmless upon guinea-pigs and 
