188 ACTION OF SALTS. 



were not destroyed by two hours' exposure in a ten-per-cent solution, 

 but a solution of five per cent killed the spores of Bacillus subtilis in 

 the same time. Koch found that anthrax spores germinated after 

 being immersed in a five-per-cent solution for thirty days. The de- 

 velopment of Bacillus prodigiosus is only slightly retarded by expo- 

 sure for sixteen hours in a one-per-cent solution. Antiseptic in the 

 proportion of 1 : 526 (Miquel). 



Zinc Sulphate. In the writer's first experiments a twenty-per- 

 cent solution failed to destroy in two hours micrococci obtained from 

 the pus of an acute abscess. In later experiments a micrococcus from 

 the same source resisted two hours' exposure to a ten-per-cent solu- 

 tion, but Micrococcus tetragenus was destroyed by this amount. 

 Broken-down beef infusion mixed with an equal quantity of a forty - 

 per-cent solution was not sterilized after two hours' contact. In 

 Koch's experiments anthrax spores were found to germinate after 

 having been immersed for ten days in a five-per-cent solution. 





