214 Profs. Percy Frankland and Marshall Ward. 



(a.) Infected unfiltered f 3 small flasks for incubator (18 — 20° C). 



water \3 „ ,, refrigerator (6 — 10° C). 



(b.) Infected porcelain- f 3 small flasks for incubator. 



filtered water ..13 ,, „ refrigerator, 



(c.) Infected steamed f 3 small flasks for incubator. 



water . . t \ 3 „ „ refrigerator. 



The contents of these flasks were then from time to time submitted 

 to bacteriological examination in the same way as in the First Series 

 of experiments. 



1. Infected Unfiltered Thames Water (Second Series). 



The results of the experiments made with the unfiltered Thames 

 water are recorded in Table VIII. 



The plates poured on the day of infection (March 25, 1892) yielded 

 about 15,000 colonies per cubic centimetre, of which about 12,000 

 were easily identifiable as anthrax. 



The second series of plates were poured 4 days later (March 29, 

 1892), but those both from the incubator and the refrigerator flask 

 were already so badly liquefied on the third day of incubation that it 

 was impossible either to count or identify any anthrax colonies. 



In consequence of this failure of the ordinary plate cultivation 

 method, the special process for anthrax identification by preliminary 

 heating was resorted to on April 13, 1892, for one of the refrigerator 

 flasks, with the result that anthrax was easily recognised. 



Ordinary plates were again poured some days later, on April 26, 

 1 892, both from an incubator and a refrigerator flask, but in neither 

 case could any anthrax colonies be found. 



Ordinary plates were again poured on June 17, 1892, but only in 

 one out of eight plates could any anthrax colonies be identified ; 

 nevertheless, when on the same day the special method by pre- 

 liminary heating to 70° C. was adopted, a number of anthrax colonies 

 were easily obtained both from the incubator as well as the re- 

 frigerator flask. This conclusively demonstrates the necessity of 

 resorting to the special method of examination, and of not relying on 

 that by ordinary plate cultivation. 



The anthrax had thus retained its vitality in the unfiltered Thames 

 water for 84 days, both when the water was maintained at a summer 

 and a winter temperature respectively, although it was undoubtedly 

 present in very much diminished numbers compared with those 

 originally introduced. 



Some of the flasks were finally examined on October 8, or 197 days 

 after the original infection, and anthrax was still discoverable by the 

 special method, although in slightly smaller numbers than on the 

 previous occasion. By comparing these numbers with those obtained 



