378 MICRO-ORGANISMS IN WATER 



Animal Experiment. — On October 7, 18925 1 c.c. of 

 water from the flask ' 5 I, Thames water, porcelain- 

 filtered, infected with anthrax on March 18, 1892, and 

 exposed to daylight since April 9, 1892,' was subcu 

 taneously injected into a white mouse. The mouse died 

 within 6 days 20 J hours. The body exhibited extensive 

 oedema ; the spleen was only slightly enlarged, but was 

 found to contain anthrax bacilli both microscopically 

 and by cultivation in gelatine. 



Animal Experiment. — On October 15, 1892, 1 c.c. 

 of water from the flask ' 5 I, Thames water, steam- 

 sterilised, infected with anthrax on March 18, 1892, 

 and exposed to daylight since April 9, 1892,' was sub- 

 cutaneously injected into a white mouse. The mouse 

 died within 4 days 17 hours ; the body exhibited much 

 cedema, and the spleen was not very large ; anthrax 

 bacilli were detected in the latter both with the micro- 

 scope and by cultivation in gelatine. 



The contrast exhibited by the sterilised and unsterilised 

 Thames water is thus most striking in the case of these 

 Jlasks exposed to daylight., for both the unjiltered and 

 paper-filtered waters failed to kill, whilst the porcelain- 

 iiltered and the steam-sterilised waters were fatal to the 

 mice into which they were injected. The lethal effect of 

 both the latter, and especially of the porcelain-filtered 

 water, accompanied by the non-typical symptom of only 

 slight enlargement of the spleen, points to an attenua- 

 tion of the virus. 



These results did not lead me to conclude, how- 

 ever, that the anthrax virus was necessarily quite 

 extinct in these two unsterilised waters (viz., the un- 

 filtered and paper-filtered Thames water), and I re- 

 sorted, therefore, to the method before employed (see 

 p. 283) of revivifying it by the addition of 5 c.c. of 

 sterile broth to each of the two flasks in question. 



