160 BACTERIOLOGY. 
atmosphere for the same time, 4 per cent. was effective, 
and when the time was extended to three hours, 1 per 
cent. destroyed their vitality. The anthrax bacillus, 
in the absence of spores, was killed by exposure in a 
moist atmosphere containing 1 part to 2500 for twenty- 
four hours. 
In watery solutions 0.2 per cent. kills spores within 
five minutes and the vegetative forms almost imme- 
diately. 
Chloride of Lime. The efficacy of chloride of lime 
depends on the chlorine it contains in the form of 
hypochlorites. A solution in water of 0.5 to 1 per 
cent. of chloride of lime will kill most bacteria in one 
to five minutes. A 5 per cent. solution usually de- 
stroys spores within one hour. 
Bromine and iodine are of about the same value as 
chlorine for gaseous disinfectants, in the moist condition; 
but, like chlorine, they are not applicable for general 
_ use in house disinfection, owing to their poisonous and 
destructive properties; they have a use in sewers and 
similar places. 
Trichloride of iodine in 0.5 per cent. solution de- 
stroys the vegetative forms of bacteria in five minutes. 
ORGANIC DISINFECTANTS. 
Aleohol in 10 per cent. solution inhibits the growth 
of bacteria; absolute alcohol kills bacteria in the vege- 
tative form in from several to twenty-four hours. 
Formaldehyde. Formaldehyde, or formic-aldehyde, 
was isolated by von Hoffmann in 1867, who obtained 
it by passing the vapors of methyl-alcohol mixed with 
air over finely divided platinum heated to redness. 
