286 BACTERIA, YEASTS, AND MOLDS 



Disinfecting Agents — Chemical 



The most common methods of disinfection employ 

 certain chemical agents known to have the power of 

 destroying bacteria. There is a long list of germicidal 

 substances. We need notice only those few agents that 

 are in common use. 



Corrosive Sublimate. This is one of the most efficient 

 germicides, and its small cost has given it wide use. The 

 most common strength for using it in ordinary conditions 

 is one part of sublimate to one thousand parts of water. At 

 this strength it rapidly kills bacteria. This strength may 

 be used for washing floors or walls of infected rooms. It 

 may be used for washing the hands after touching infec- 

 tious materials. It is an excellent antiseptic, but there 

 are two objections to it. (i) It is intensely poisonous, and 

 the greatest care must be exercised in handling it, to pre- 

 vent it from reaching the mouth. (2) It has a strong cor- 

 rosive action on metals and cannot be used on anything 

 made of iron or steel. These facts limit its use, but never- 

 theless it is one of the best and most widely used of chem- 

 ical disinfectants. A solution of proper strength, one to 

 one thousand, may be made by dissolving one quarter of 

 an ounce of corrosive sublimate in two gallons of water. 

 A more effective solution is as follows. 



Corrosive sublimate .... 15 grains (i gram) 



Common salt 30 grains (2 grams) 



Water i quart (1000 grams) 



Carbolic Acid. This material has been used longer than 

 any other disinfectant, and is very efficient, though less 

 so than corrosive sublimate. It is commonly used in a 



