DEVELOPMENT OF THE BACTERIA. 121 
bacteria, if Crova had not recently asserted that 
movements impressed upon aliquid containing 
bacteria completely arrests their development. 
This is an assertion in complete opposition to all 
that we know of the physiology of these organ- 
isms, and which it 1s difficult to reconcile with the 
fact that bacteria may develop even in the torrent 
of the circulation. 
Compressed Air. — We have just seen the in- 
fluence of air, and especially of oxygen, upon the 
bacteria. When this agent is in a certain state of 
tension, it acts in a different manner. M. Paul 
Bert has proved that under a tension of twenty- 
three to twenty-four atmospheres all the putrefac- 
tive processes depending upon the development of 
vibrios cease to occur. Since, the same savant 
has found that the anatomical elements and even 
the red blood globules are killed by oxygen. 
These researches agree well enough with those of 
Grossmann and Mayerhauser upon the lite of 
bacteria in gas. From their numerous experi- 
ments it appears that, under the influence of oxy- 
gen, there is an exaggeration of the activity of 
the bacteria; but if the oxygen is under a pres- 
sure of five to seven atmospheres, the bacteria live 
from six to twenty hours, then die, and cannot be 
resuscitated by atmospheric air. 
Ozone causes a definite and almost instantaneous 
arrest of movement. 
