670 
E. ROUX, L. MARTIN AND A. CHAILLOU. 
4. The anti-diphtheritic serum in diphtherias complicated by 
the association of other bacteria .—The diphtherias thus associ¬ 
ated with or complicated by the presence of other bacteria, 
especially the streptococci, are among the most seveie that are 
to be seen. Most frequently the disease involves the lungs, 
which, at autopsy, show foci of broncho-pneumonia, wherein 
are found the diphtheritic bacilli and the streptococci. Roux 
and Yersin have already shown that a virus of small virulence 
may become deadly for guinea-pigs when inoculated at the 
same time as a streptococcus not very virulent by itself. Is the 
anti-diphtheritic serum capable of curing these complicated 
cases ? This constitutes a question of the greatest interest on 
account of the frequency of the existence of these mixed forms 
in children. Dr. Funk has investigated it, and finds that this 
simultaneous infection determines an increase in the production 
of the diphtheritic toxine, but that the presence of the strep- 
toccus does not prevent in any way the neutralizing effects of 
the antitoxine. Hence, in these cases, we must simply inject 
larger amounts of antitoxine. 
Funk inoculates under the skin ; we inject in the trachea so 
as to imitate as closely as possible the actual conditions of 
practice. The bacilli and streptococci were inoculated in the 
manner mentioned above. The streptococci had been taken 
from a diphtheritic child, and were therefore one of those forms 
that are found in associated diphtherias. Isolated in a pure 
culture, it does not cloud broth and is not very virulent for rab¬ 
bits. Two cc. of a recent culture in broth, injected in the 
veins of a rabbit, only kills him after ten days. One cc. intro¬ 
duced under the skin causes an erysipelatous sore, with tran¬ 
sitory fever, and without serious disturbance of the health. The 
same amount placed in the trachea of a tracheotomized rabbit 
gives it a brief elevation of temperature without pronounced 
malaise. The diphtheritic bacillus added to it is the same viru¬ 
lent one that has served in our other experiments. 
The association of these two microbes produces in rabbits a 
diphtheria running a rapid course, as seen in very young 
