BACILLUS PROTEUS VULGARIS. 539 
twelve hours reached 38.8° C.; an erysipelatous-like 
swelling of the forearm occurred, and the glands in 
the axilla were swollen and painful. Neumann has 
obtained the bacillus pyocyaneus in pure culture in 
two cases of hematemesis and melena of the new-born 
from the blood and other organs. Lartigau found it 
in well-water, and in great abundance in the intestinal 
discharges of a number of cases made ill by drinking 
the water. 
We may, therefore, conclude from these facts that 
the bacillus pyocyaneus, although ordinarily non-patho- 
genic for man, may under certain conditions become a 
dangerous source of infection. Children would seem 
to be particularly susceptible to this infection. 
The differential diagnosis of the pyocyaneus from 
other fluorescing bacteria is easy enough as long as it 
retains its pigment-producing property. When an agar 
culture is agitated with chloroform a blue coloration 
demonstrates the presence of this bacillus. When the 
pyocyanin is no longer formed, however, the diagnosis 
is by no means easy, particularly when the pathogenic 
properties are also gone. 
BACILLUS PROTEUS VULGARIS. 
This bacillus, which is one of the most common and 
widely distributed putrefactive bacteria, was discovered 
by Hauser (1885) along with other species of proteus 
in putrefying substances. These bacteria were formerly 
included under the name“ bacterium termo” by previous 
observers, who applied this name to any minute motile 
bacilli found in putrefying infusions. 
Morphelogy. Bacilli varying greatly in size; most 
commonly occurring 0.6% broad and 1.2” long, but 
