206 



Profs. Percy Frankland and Marshall Ward. 



from the flask " 5 I, Thames water, steam-sterilised, which had been 

 infected with anthrax on March 18, 1892, and exposed to daylight 

 since April 9, 1892," was subcutaneously injected into a white mouse. 

 The mouse died within 4 days 17 hours; the body exhibited much 

 oedema and the spleen was not very large; anthrax bacilli were 

 detected in the latter both with the microscope and by cultivation in 

 gelatine. 



The contrast exhibited by the sterilised and unsterilised Thames water 

 is thus again most striking in the case of these flasks exposed to daylight, 

 for both the unfiltered and paper-filtered waters failed to kill, whilst the 

 porcelain, filtered 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 

 again to an attenuation of the virus. 



These results did not lead me to conclude, however, that the 

 anthrax virus was necessarily quite extinct in these two unsterilised 

 waters (viz., the unfiltered and paper-filtered Thames water), and I 

 resorted, therefore, to the method before employed (see p. 194) of 

 revivifying it by the addition of 5 c.c. of sterile broth to each of the 

 two flasks in question. The flasks so treated were placed in an in- 

 cubator at 37° C, and the following further experiments made with 

 them : — 



Animal Experiment No. 20. — On October 22, 1892, 0*5 c.c. of the 

 water (to which broth had been added on October 15, 1892) in the 

 flask " 1 I, Thames water, unfiltered, and infected with anthrax on 

 March 18, 1892, exposed to daylight since April 9, 1892," was sub- 

 cutaneously injected into a white mouse. The mouse died within 

 2 days 18 hours. The body exhibited extensive oedema and the 

 spleen was much enlarged ; the latter was found full of anthrax 

 bacilli, the presence of which was confirmed by cultivation in 

 gelatine. 



Animal Experiment No. 17. — On October 18, 1892, 0*5 c c. of the 

 water (to which broth had been added on October 15, 1892) in the 

 flask " 5 I, Thames water, paper-filtered, and infected with anthrax 

 March 18, 1892, exposed to daylight since April 9, 1892," was sub- 

 cutaneously injected into a white mouse. The mouse died within 

 1 day 19 hours. Only few bacilli were found in the spleen, but more 

 in the kidney ; their presence was confirmed by gelatine cultivations 

 from both organs. 



These experiments show, then, that in the flasks in question {un- 

 sterilised Thames water exposed to daylight), although the number of 

 anthrax germs had been so far reduced that 1 c.c. would not kill mice, 

 yet after nourishment with broth they were so revivified as to be fatal to 

 these animals whe.i injected in the same or even a smaller quantity. 



