568 APPLICATION OF METHODS OF BACTERIOLOGY 



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 impor- 

 tance 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 bac- 

 teriological means for making the diagnosis, to bear in mind 

 those biological and morphological features of the organism 

 that appear most quickly under artificial methods of cul- 

 tivation, and which, at the same time, may be considered 

 as characteristic of it, viz., its peculiar morphology and 

 grouping; the much greater rapidity of its growth over that 

 of other bacteria with which it may be associated; the 

 characteristic appearance of its colonies on gelatin plates 

 and of its growth in stab-cultures in gelatin; its property 

 of producing indol and coincidently nitrites in from six to 

 eight hours in peptone solution at 37 to 38 C.; and its 

 power of causing the death of guinea-pigs in from sixteen 

 to twenty-four hours when introduced into the peritoneal 

 cavity, death being preceded by symptoms of extreme 

 toxemia, characterized by prostration and gradual and 

 continuous fall in the temperature of the animal's body. 



Koch 1 devised a plan of procedure that comprehends the 

 points just enumerated. By its employment the diagnosis 

 can be established in the majority of cases of Asiatic cholera 



1 Zeitschrift fur Hygiene und Infektionskrankheiten, 1893, Bd. xiv, S. 319. 



