176 MICROBES, FERMENTS, AND MOULDS. 
III. Toe Virvutent Micrope or Heatray Human 
SALIVA. 
Pasteur and Vulpian in France, and Sternberg in 
America, discovered almost simultaneously that the 
human saliva may, under conditions with which we 
are still imperfectly acquainted, become virulent, and 
that this virulence is due to the action of a Micrococcus, 
normally present in the saliva, a microbe quite distinct 
from that of rabies, of which we have already spoken. 
It is only known that this micrococcus is very 
common in the saliva of a healthy man, and that in 
some individuals the saliva is exceptionally virulent. 
When injected under the skin of healthy rabbits, it 
produces grave affections, often resulting in the animal’s 
death. These affections are due to the presence of 
the micrococcus, since the saliva becomes harmless as 
soon as these organisms are removed from it. 
Sternberg informs us that his own saliva is 
among those which possess this curious and alarming 
property. He regards the more abundant nutriment 
which this microbe finds in the mouths of some 
persons as the cause of this virulence, since thus its 
development is more energetic. “In my own case,” 
he writes, “there is a very abundant secretion of 
saliva. ... My culture experiments show that this 
micrococcus multiplies very rapidly, and in virtue of 
this faculty it has for a certain time the advantage 
