196 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. 
