SPIRILLUM CBOLEBjE ASIATICS. 465 



C. ; but it is slower, the maximum development of the 

 cholera organisms being reached at about the fifteenth 

 hour, after \s'hich time they were outnumbered by the 

 ordinary saprophytes present. 



From the foregoing it would seem that the vitality of 

 the cholera spirillum in milk depends largely upon the 

 reaction : the more quickly the milk becomes sour the 

 more quickly does the organism become inert; while 

 the longer the milk retains its neutral, or only very 

 slightly acid, reaction, the longer do the cholera organ- 

 isms that may be present in it retain their power of 

 multiplication. 



According to Laser,' the cholera organism retains its 

 vitality in butter for about seven days ; it is therefore 

 possible for the disease to be contracted by the use of 

 butter that has in any way been in contact with cholera 

 material. 



In regard to the antagonism between the cholera 

 spirillum and other organisms with which it may come 

 in contact, the experiments of Kitasato^ led him to 

 conclude that no organism has been found which, 

 when growing in the same culture-medium with it, 

 possessed the power of depriving it of vitality within 

 n short time. On the other hand, the experiments 

 showed that there were quite a number of other organ- 

 isms the development of which was checked, and in 

 some cases their vitality was completely destroyed, 

 when growing in the same medium with the cholera 

 spirillum. 



From this it would appear that the disappearance of 

 the cholera spirillum from mixed cultures and from the 

 evacuations in the short time mentioned, is due more 



1 Zeitschrift fur Hygiene. Bd. x. S. 513. ' Ibid., Bd. vi. S. 1. 



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