204 Profs. Percy Frankland and Marshall Ward. 



43—44 colonies per 1 c.c. were found in one flask (1 R, porcelain, 

 Table IV) by ordinary plate cultivation, only 2 — 5 colonies in the 

 same volume were found after the preliminary heating to 70° C. for 

 2 minutes. On comparing these results with those obtained by the 

 same method in the case of the unsterilised waters, it will be seen that 

 there is distinct evidence of the anthrax organs undergoing more 

 rapid degeneration in the latter than in the sterilised waters. The 

 degeneration is, however, in any case, only an extremely slow one. 



There is hardly any difference to be found between the results 

 yielded by the sterile waters kept at summer and winter tempera- 

 tures respectively, but such slight difference as there is points rather 

 to the degeneration of the anthrax being more retarded at the low 

 than at the higher temperature. 



One of these waters was also examined for virulence in October, or 

 7 months after infection with anthrax, and the following results 

 obtained : — 



Animal Experiment No. 9. — On October 15, 1892, 1 c.c. of water 

 from the flask " 1 R, Thames water, porcelain-filtered, infected with 

 anthrax, March 18, 1892," was subcutaneously injected into a white 

 mouse. The mouse died within 4 days 17 hours. Anthrax bacilli 

 were found in the spleen and by cultivation in gelatine. There was 

 extensive oedema, and the spleen was not much enlarged. 



Thus, in the water sterilised by filtration through porous porcelain the 

 anthrax ivas still present after 7 months, in sufficient numbers for 1 c.c. 

 to cause the death of the mouse, although from the comparatively slow 

 action and non-typical symptoms it had apparently become somewhat 

 attenuated. 



I did not consider it necessary to make a corresponding experiment 

 with the steam- sterilised Thames water, as, owing to the similarity 

 between the results obtained by plate cultivation from both types of 

 sterilised water, it appeared only reasonable to assume that their 

 virulent effect would also be much the same. 



5. Vitality and Virulence of Anthrax in Thames Water (First Series} 

 Exposed to Diffused Daylight. 



In all the experiments hitherto referred to, the waters were pre- 

 served in total darkness, the flasks containing them being placed in 

 an incubator and refrigerator respectively. Further experiments 

 were, however, made with the same waters, exposed to diffused day- 

 light, at the ordinary temperature of the laboratory, and others, again, 

 in which the flasks were exposed to direct sunshine. 



The results of the experiments with Thames water (First Series), 

 exposed to diffused daylight, are recorded in Table VI. 



All the flasks employed in these experiments had been in the 



