Report on the Bacteriology of Water. 279 



The results (see Table F) showed that spores had remained alive 

 for seven months in the flask, and though enfeebled they were capable 

 of germinating and killing. 



Flask B, March 5 to October 6, 1892. — B was also a 1-litre flask, 

 filled with about 500 c.c. Thames water, and inoculated with 8 c.c. 

 of the anthrax infection. 



Kept in the open laboratory. Cotton-wool plug. Under bell- jar. 

 At east window. Partial insolation in mornings. Temperature varied 

 from 12°to 20° C. 



After being thus undisturbed till October 6 — i.e., seven months — 

 the plates showed no anthrax, though numerous other (water) 

 bacteria were present. 



A guinea pig inoculated with 2 c.c. of the water did not die in 

 fourteen days. 



Cultures from plates of the water, after exposure at 56° for twenty- 

 four hours, showed no anthrax. 



This result shows either (1) insolation killed off the spores, or 

 (2) the temperature was not high enough for spores to form. That 

 the first suggestion is the right one will be shown in the sequel. 



Flash B', March 5 to October 6, 1892.— 1-litre flask of Thames 

 water exactly like B, and inoculated in the same way. 



The only difference in treatment was that B' was placed at 20° C. 

 in the incubator, and remained two months at that temperature ; 

 then, still in incubator, it was left through the summer in the dark, at 

 the same temperature as B. 



Plates on October 6 (i.e., seven months later) gave no anthrax, 

 either from water direct or after twenty-four hours at 56° C. Any 

 anthrax-like colonies turned out to be saprophytes. 



Nevertheless a guinea pig inoculated with 2 c.c. of the water died 

 in three days, and cultures of anthrax were made from the heart. 



Suggests that spores developed well, and kept well, but that they 

 were either too few or too feeble to be easily detected on gelatine. 



Flash C, March 5 to October 6, 1892.— 1-litre flask filled with Thames 

 water and boiled for half an hour, and then inoculated with 2 c.c. 

 (therefore water organisms introduced), exactly as before. 



Kept at 20° C. for two months in dark incubator, then remained 

 (in same) for five months at ordinary temperatures. 



On October 6 plate cultures gave no anthrax, though other organ- 

 isms were shown. After twenty-four hours at 56° C, plates also 

 gave no results; bub a guinea pig inoculated with 2 c.c. of the water 

 died in five days, and the heart's blood gave cultures of anthrax. 



Suggests that boiling the Thames water in no way hurts it as a 

 medium for anthrax to sporify in. 



Flash D, March 5 to October 6, 1892.— 1-litre flask filled with crude 

 Thames water, and not inoculated. 



u 2 



