DISINFECTANTS AND ANTISEPTICS. 2C5 



market. In operating with these, a sufficient number are 

 placed on bricks in a pan of water and the wicks lighted. 

 Liquefied sulphur dioxide may be used, and can now be 

 obtained in convenient tin receptacles containing a suffi- 

 cient quantity for the disinfection of an ordinary room. 

 The can is opened by cutting through a soft metal tube 

 projecting from the top. The fluid vaporizes at the room 

 temperature, and it is simply necessary to place the can in a 

 convenient porcelain dish and allow the fluid to evaporate. 



Sulphur dioxide is objectionable on account of its lack 

 of power when dry, and on account of its corrosive action 

 on metal and its bleaching effect on hangings and draperies 

 in the presence of moisture; it is, therefore, preferable to 

 use formaldehyde when possible. 



Chlorine. A very active gaseous disinfectant, particu- 

 larly in the presence of moisture. An atmosphere con- 

 taining i per cent, of the dry gas is fatal to anthrax spores 

 in three hours. The anthrax bacillus is killed in twenty- 

 four hours by exposure to a moist atmosphere containing 

 the gas in the proportion of 1-2500. The bacillus of tuber- 

 culosis is killed by an exposure of one hour to a moist atmos- 

 phere containing the gas in the proportion of 1-200. Ex- 

 tremely minute quantities in solution will prevent the 

 development of putrefactive organisms. The substance 

 has been used for house and ship disinfection, but is now 

 seldom employed on account of its extremely irritating 

 properties and the difficulty of handling it. 



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 aqueous so- 

 lution 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 con- 



