1889.] Bacteriology. yij 
(Cholera and Anthrax), are destroyed by the CO^ more or less com- 
In spite of this influence of CO^ in checking development, and in 
some cases in partially destroying the germs, it is not available as a 
means for preventing putrefaction, and is therefore not an antiseptic 
in the narrower sense of that term. A relatively insignificant admix- 
ture of ordinary air allows a rich development of even the kinds of 
bacteria most sensitive towards CO^. 
CO2, then, for some micro-organisms is not an indifferent gas, but 
exerts a strongly inhibitory influence upon their multiplication, and in 
some cases destroys part of the germs submitted to its action. That 
this injurious effect is not due to the absence of oxygen is shown by 
the fact that a number of this group are anaerobic in habit. For 
other kinds of bacteria CO, is apparently wholly inert.— E. O. Jordan. 
The New Science of Hygiene. — Whatever his opinions of 
the modern times may be in other respects every one must admit that 
the present contrasts most sharply with the past in its keen sensitiveness 
to the public welfare. Especially is this true of great cities, which 
have gone so far in this direction that it seems to be their highest en- 
deavor to overcome the obstructions to the public health incurred by 
unnatural conditions such as density of population, and to work out 
for themselves new and better conditions of existence. A new root 
has sprung from the tree of knowledge, and hygienic science is shed- 
ding its light even in the darkest places, and civilized nations are has- 
tening to meet this new necessity by the establishment of hygienic 
laboratories, yet at the same time it is but a one-sided view which re- 
gards hygiene as the handmaid of medicine only ; on the contrary, it 
touches practical life in manifold ways of the utmost importance. — 
Zeitschrift fur Hygiene. 
