256 MANUAL OF BACTERIOLOGY. 



cent, of the dry gas is fatal to anthrax spores in three hours. 

 The anthrax bacillus is killed in twenty-four hours by ex- 

 posure to a moist atmosphere containing the gas in the pro- 

 portion of 1-2500. The bacillus of tuberculosis is killed by an 

 exposure of one hour to a moist atmosphere containing the gas 

 in the proportion of 1-200. Extremely minute quantities in 

 solution will prevent the development of putrefactive organ- 

 isms. The substance has been used for house and ship disin- 

 fection, but is now seldom employed on account of its extremely 

 irritating properties and the difficulty of handling. 



Bromine. — Used in the gaseous and liquid form. The dry 

 vapor possesses but little disinfectant power; when moist it 

 is much more efficient. In saturated acqueous solution it will 

 kill the anthrax bacillus in twenty-four hours. 



Calcium Hypochlorite, usually known as Chloride of Lime. — 

 This is a most practical and valuable disinfectant, depending 

 for its efficiency on the. available chlorine contained in it. Its 

 alkalinity favors penetration, and for many purposes it can- 

 not be excelled. A i per cent, solution will destroy anthrax 

 spores in one hour. A solution of the same strength will disin- 

 fect typhoid stools in ten minutes. 



Lime. — The addition of o.i per cent, of unslaked lime to 

 fluid-cultures of the typhoid bacillus and cholera spirillum will 

 render them sterile in four or five hours. Typhoid dejecta are 

 sterilized in six hours by the addition of 3 per cent, of slaked 

 lime; the addition of 6 per cent, will accomplish the same result 

 in two hours. A convenient form for practical use is an aqueous 

 mixture containing 20 per cent, of lime — so-called milk of 

 lime. Typhoid and cholera dejecta are sterilized in one hour 

 after the addition of 20 per cent, of this mixture. In practice 

 it is safer to use a considerable excess of lime. From the fore- 

 going facts it would seem probable that lime or whitewash as 

 ordinarily applied would possess disinfectant properties. Ex- 

 perimental work has demonstrated this to be a fact. The 



