DIAGNOSIS OF ASIATIC CHOLERA. 335 



cultures in gelatin ; its property of producing indol and 

 coincidently nitrites in from six to eight hours in pep- 

 tone 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 

 toxaemia, characterized by prostration and gradual and 

 continuous fall in temperature of the animal's body. 



In a publicatioii recently made by Koch' he called 

 attention to a plan of procedure that is employed in 

 this work in the Institute for Infectious Diseases at 

 Berlin. In this scheme the points that have been 

 enumerated are taken into account, and by its employ • 

 ment the diagnosis can be established in the majority 

 of cases of Asiatic cholera in from eighteen to twenty- 

 two hours. In general the steps to be taken and points 

 to be borne in mind are as follows. The material 

 should be examined as early as possible after it has 

 been passed. 



I. Microscopic examination. From one of the small 

 slimy particles that will be seen in the semi-fluid evac- 

 uations prepare a cover-slip preparation in the ordinary 

 way and stain it. If, upon microscopic examination, 

 only curved rods, or curved rods greatly in excess of 

 all other forms, are present, the diagnosis of Asiatic 

 cholera is more than lihely correct ; and particularly is 

 this true if these organisms are arranged in irregular 

 linear groups with the long axes of all the rods point- 

 ing in nearly the same direction, that is to say, some- 

 what as minnows arrange themselves when swimming 

 in schools up stream. (Koch.) 



In 1886 Weisser and Frank ^ expressed their opinion 



1 Zeitschrift far Hygiene, 1893, Bd. xiv. 2 ibid., Bd. i., p. 397. 



