MICROSPIRA COMMA. 475 



intestinal evacuations of human beings it lost its vitality 

 in from a day and a half to three days. If the evacua- 

 tions were sterilized before the cultures were mixed with 

 them it retained its vitality from twenty to twenty-five 

 days. 



Hesse 1 and Celli 2 demonstrated that many substances 

 commonly employed as food serve as favorable materials 

 for the development of the cholera organisms. 



Kitasato 8 found that at 36 C. microspira comma 

 developed very rapidly in milk during the first three or 

 four hours, and outnumbered the other organisms com- 

 monly present. It then diminished in number from 

 hour to hour as the acidity of the milk increased, until 

 finally its vitality was lost; at the same time the com- 

 mon saprophytic bacteria increased in number. Rela- 

 tively the same process occurs at a lower temperature, 

 from 22 to 25 C. ; but it is slower, the maximum 

 development of the cholera organisms being reached at 

 about the fifteenth hour, after which time they were 

 outnumbered by the ordinary saprophytes present. 



From the foregoing it would seem that the vitality of 

 microspira comma in milk depends largely upon the 

 reaction ; the more quickly the milk becomes sour the 

 more quickly does the organism become inert. 



According to Laser, 4 the cholera organism retains its 

 s- itality 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. 



i Zeitschrift fur Hygiene, Bd. v. S. 527. 

 sBolletino della R. Acad. Med. di. Roma, 1888. 

 s Zeitschrift fur Hygiene, Bd. v. S. 491, 

 * Laser : Zeitschrift fur Hygiene. Bd. x. S. 513. 



