112 ESSENTIALS OF BACTERIOLOGY. 



cholera bacillus a rose-red color is produced. This will riot take 

 place with other bacilli unless nitrous acid is present. The cholera 

 bacillus forms nitrites from the nitrates present in the media, 

 and also indol. The mineral acid splits the nitrites, setting free 

 nitrous acid, which, with the indol, forms the red reaction. 

 This pigment has been isolated and extracted and called 

 " cholera red." A ptomaine, identical with cadaverin, and sev- 

 eral other alkaloids have been obtained from the cultures. A 

 toxalbumen and a toxicpeptone have lately been isolated, but 

 no special actions ascribed to them. 

 Bacteria Similar to the Spirillum of Cholera. 

 Finkler-Prior Vibrio, or Spirillum Finkleri. 

 Origin. Found in the intestinal contents of a patient suffer- 

 ing from cholera Asiatica in 1884, by Finkler and Prior, who 



thought it identical with the spi- 

 Fio. 60. ^ rillum of cholera ; it differs from 



^>>. it, however, in many ways, and 

 ff^ has been found in healthy per- 

 */ sons. 



~><vf>^ 'V^r Form. Somewhat thicker than 



^ -^'i' ' ^ e c hl era vibrio, otherwise 



^Of^"" about the same form ; it forms 



Jf $ the long spirilla less often. Has 



Flagella. 



Spirillum ^"^^J 00 diamete Properties. -It is very motile. 



Liquefies gelatine in a short time. 



Groicth.!t grows quickly at ordinary room temperature. It 

 is facultative aerobic. 



Colonies on Gelatine Plates. Hound, finely granular colonies, 

 which in twenty-four hours are ten times as large as the cholera 

 colonies, and in forty-eight hours the whole plate is liquefied, 

 it being then impossible to distinguish any separate colonies. 

 The microscopic appearances in no way resemble the cholera 

 colony. 



Stab Cultures. The gelatine is liquefied from above down- 

 wards, like a stocking in appearance, and in three days is com- 

 pletely liquid. 



