BACTERIOLOGICAL TECHNIQUE. 233 
made a gas-pressure regulator is added to the thermo- 
regulator. Incubators are also both warmed and regu- 
lated by electricity. — 
In emergencies a culture may be developed at the 
blood temperature by placing it in water contained in 
a small vessel, which itself is contained in a larger 
vessel, also filled. By adding a little hot water from 
time to time the temperature can readily be kept be- 
tween 34° and 38° C., which is sufficiently uniform for 
bacteria such as the diphtheria bacilli to grow. 
As a temporary expedient during the night, when 
haste is necessary, it is possible, when the culture medium 
is solid and within a strong glass tube or metal case, 
to make use of the body heat by putting it under the 
clothing next to the body and sleeping upon it. Natu- 
rally, this should only be done when other means fail. 
Several times, when in the country, this method has 
enabled the writer to obtain a growth of diphtheria 
bacilli over night, and thus get important information, 
when otherwise it would have been impossible. 
Culture Methods for Anaerobic Bacteria. 
Anaérobic bacteria will scarcely be cultivated except 
in bacteriological laboratories, where the technique is 
already understood, so that the methods employed in 
their culture will only be touched on here. A simple 
device is that of Koch, who placed a thin strip of 
sterile mica upon the still fluid agar or gelatin in the 
Petri dish, which had already been inoculated. After 
the solidification of the media the portion under the 
mica is excluded from the air and anaérobic growth can 
develop. A second simple method (Liborius) is to fill 
the tubes with media fuller than usual and to inoculate 
