ACTION OF LIGHT ON MICRO-ORGANISMS 379 



The flasks so treated were placed in an incubator at 

 37 C., and the following further experiments made 

 with them : 



Animal Experiment. On October 22, 1892, 0*5 c.c. 

 of the water (to which broth had been added on 

 October 15, 1892) in the flask c l I, Thames water, 

 unfiltered, and infected with anthrax on March 18, 

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

 subcutaneously injected into a white mouse. The 

 mouse died within 2 days 18 hours. The body ex- 

 hibited 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. 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 

 subcutaneously injected into a white mouse. The 

 mouse died within 1 day ] 9 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 (unsterilised Thames water exposed for upwards 

 of six months to diffused 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 when injected in 

 the same or even a smaller quantity. 



