376 MICRO-ORGANISMS IN WATER 



of the anthrax cultures tested in the various waters after 

 insolation, but their virulence was directly determined 

 by inoculation into white mice. 



The water used in these experiments was obtained 

 from the river Thames and was employed unsterilised, 

 after nitration through Swedish paper, after nitration 

 through porcelain (Chamberland), and after steam 

 sterilisation. The flasks containing these several de- 

 scriptions of water were inoculated with anthrax spores 

 and kept in the incubator (18-20 C.) or refrigerator 

 (6-10C.). In the description of the results obtained, 

 those flasks against which an ' I ' is placed were put in 

 the incubator, whilst those marked ' B ' were preserved 

 in the refrigerator. The numerals appended to the 

 letters indicate the particular flask examined in each of 

 the several series. 



Vitality and Virulence of Sporiferous Anthrax in Thames 

 Water Exposed to Diffused Light (Percy Frankland) 



All the flasks employed in these investigations 

 had been in the refrigerator or incubator from the 

 day of infection with anthrax (March 18, 1892) until 

 March 25, 1892, from when they remained in a dark 

 room until April 9, 1892, after which they were 

 exposed to the diffused daylight in a room with a 

 southern aspect. 



The anthrax in the previously sterilised (porcelain 

 and steam) Thames water survived this exposure of 

 upwards of two months to diffused daylight, nor did 

 the number of colonies obtained on plate cultivation 

 differ materially from that obtained from the correspond- 

 ing flasks preserved throughout in the dark. Indeed, 

 by direct experiments on animals (see pages 377-379) 

 it was shown that the anthrax remained both alive and 



