56 ELEMENTS OF WATER BACTERIOLOGY. 



scopically, and if comma-shaped organisms are present, 

 inoculations are made into fresh tubes to be further tested 

 by means of the indol reaction and by inoculation into 

 animals. The existence of other spirilla of some patho- 

 genic power renders necessary the greatest care and 

 caution in claiming positive isolations. That no great 

 improvement on Koch's method has been made during 

 the last ten years seems apparent from the statements of 

 Kolle and Gotschlich (Kolle and Gotschlich, 1903), who 

 employed "the peptone method with subsequent agar 

 cultivation" in the isolation of the organisms from faeces 

 of cholera patients during the epidemic in Egypt in 1902, 

 and who have made notable epidemiological and clinical 

 researches upon this disease. 



Other pathogenic organisms have been isolated from 

 waters, according to the accounts of numerous investi- 

 gators, but from the sanitary point of view the typhoid 

 and cholera bacilli are of most importance since these are 

 manifestly the germs of disease most likely to be dissemi- 

 nated through this medium. For the detection of B. 

 anthracis and other spore-forming pathogenic bacteria 

 which may at times gain access to water from stockyards, 

 slaughter-houses, etc., the method suggested by Frank- 

 land (Frankland, 1894) may be adopted. The water 

 to be examined is heated to 90 for two minutes and then 

 plated, the characteristic colonies of the anthrax organism 

 being much more easily discerned after the destruction of 

 the numerous non-sporing water bacteria. Again, water 

 is sometimes the means of distributing the germs of 



