176 PHYSIOLOGY OF THE BACTERIA. 



Bacteria in Liquids Exposed to the Air. — In 

 order to comprehend the importance of bacteria 

 from a surgical point of view, it is sufficient to put 

 a drop of pus from an open wound under the micro- 

 scope. In the majority of cases the presence of 

 bacteria will be demonstrated. And, truly, there 

 is nothing in this which should astonish us, if we 

 remember what has been said above, since we 

 know the facility with which these vegetables de- 

 velop in all the liquids of the organism, and the 

 resistance which they offer to all but the most 

 powerful agents. However, all pus is not equally 

 suitable for the development of these organisms. 

 It is easy to remark that they are more abundant 

 in pus of a bad character, in that which smells bad 

 and exhales an odor of butyric acid. They are 

 also more commonly found in pus which has re- 

 mained a long time in wounds having hidden si- 

 nuses. But while recognizing these differences, 

 we must confess that there is nothing absolutely 

 fixed about them, and above all that they do not 

 bear a constant relation with the conditions which 

 govern the genesis of putridity. 



It is certain, also, that the conditions surround- 

 ing the sick person, the quality of the air in which 

 his wound is bathed, are conditions which it is 

 necessary to consider. And this results from 

 what we have said relative to atmospheric germs. 

 For example, when we submit to maceration in 

 distilled water, dust gathered in a hospital, on one 

 hand, and on the other, dust from a different lo- 

 cality, taken in the country, for instance. The 



