564 APPLICATION OF METHODS OF BACTERIOLOGY 



As a rule, bacteriological examination fails to reveal the 

 presence of the organisms in the blood and internal organs 

 in this disease, though exceptions have been noted. 



Microspira comma is a facultative saprophyte; that is 

 to say, it apparently finds in certain parts of the world, 

 particularly in those countries in which Asiatic cholera is 

 endemic, conditions that are not entirely unfavorable to 

 its development outside of the body. This was found to 

 be the case not only by Koch, who detected the presence 

 of the organism in water-tanks in India, but by many 

 other observers who have succeeded in demonstrating its 

 growth under conditions not embraced in the ordinary 

 methods employed for the cultivation of bacteria. 1 



The results of experiments having for their object the 

 determination of the length of time during which the 

 organism may retain its vitality in water are conspicuous 

 for their irregularity. 



Koch states that in ordinary spring-water or well-water 

 the organisms retained their vitality for thirty days, whereas 

 in the sewage of Berlin they died after six or seven days; 

 but if this latter were mixed with fecal matters, the organ- 

 isms retained their vitality for but twenty-seven hours; 

 and in the undiluted contents of cesspools it was impossible 

 to demonstrate them after twelve hours. In the experi- 

 ments of Nicati and Rietsch they retained their vitality 

 in Marseilles sewage for thirty-eight days; in sea-water, 

 sixty-four days; in harbor-water, eighty-one days; and in 

 bilge-water, thirty-two days. 



In one test with the water-supply of Berlin the organism 



1 Obviously all pathogenic bacteria that have been isolated under artificial 

 methods of cultivation are facultative saprophytes. Were they obligate 

 parasites, their cultivation upon dead materials would be impossible. 



