476 BA CTERIOL OGY. 



When dried microspira comma retains its vitality for 

 from about three to twenty-four hours, according to the 

 degree of dessecation. In moist conditions vitality may 

 be retained for many months ; though repeated observa- 

 tions lead us to believe that under these circumstances 

 virulence is diminished. 



Carbon dioxide, carbon monoxide and nitrous oxide 

 gases kill this germ in from seven to ten days. 



From what has been said, we see that the spirillum 

 of Asiatic cholera, while possessing the power of pro- 

 ducing in human beings one of the most rapidly fatal 

 diseases with which we are acquainted, is still one of the 

 least resistant of the pathogenic organisms known to us. 

 Under conditions most favorable to its growth its de- 

 velopment is self-limited ; it is markedly susceptible to 

 acids, alkalies, other chemical disinfectants, and heat ; 

 but when partly dried upon clothing, food, or other 

 objects, it may retain its vitality for a relatively long 

 period of time, and it is more than probable that in this 

 way the disease is often disseminated from points in 

 which it is epidemic or endemic into localities that are 

 free from it. 



THE DIAGNOSIS OF ASIATIC CHOLERA BY BACTERIO- 

 LOGICAL METHODS. 



Because of the manifold channels that are open for 

 the ready dissemination of this disease it is of the 

 utmost importance that it should be recognized as 

 quickly as possible, for with every moment of delay 

 opportunities for its spread multiply. It is essential, 

 therefore, when employing bacteriological means for 

 making the diagnosis, to bear in mind those biologi- 

 cal and morphological features of the organism that 



