206 MANUAL OF BACTERIOLOGY. 



tained in it. Its alkalinity favors penetration, and for 

 many purposes it cannot be excelled. A I per cent, solu- 

 tion will destroy anthrax spores in one hour. A solution 

 of the same strength will disinfect 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 spiril- 

 lum will render them sterile in four or five hours. Ty- 

 phoid 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 foregoing facts 

 it would seem probable that lime or whitewash as ordi- 

 narily applied would possess disinfectant properties. Ex- 

 perimental work has demonstrated this to be a fact. The 

 organisms of anthrax, glanders and the pus cocci were 

 destroyed within twenty-four hours by one application. 

 For spore-forming organisms and the bacillus of tubercu- 

 losis the power is not so great, the latter organism not 

 being destroyed by three applications of the whitewash. 

 This is due, perhaps, to the large amount of fatty matter 

 in the bacillus of tuberculosis, and suggests the possibility 

 of enhancing the efficacy of the lime by the addition of a 

 small proportion of caustic alkali. 



Hydrogen Peroxide. This substance is placed on the 

 market in solutions varying in strength from 10 to 30 vol- 

 umes ; the mode of expression indicating that correspond- 

 ing solutions will liberate ten to thirty times their volume 

 of oxygen when appropriately treated. It possesses the 

 property of rapidly oxidizing purulent secretions, and on 



