FERMENTATION AND GERM DISEASES 73 



STERILIZATION AND DISINFECTION 



In connection with bacteria and germ diseases, we fre- 

 quently hear the terms, sterilization and disinfection. To 

 disinfect means to treat a thing in such a manner as to destroy 

 any micro-organisms that might produce infection or disease. 

 If there were harmful bacteria in water and we could kill them 

 without injuring the water, evidently the danger in drinking it 

 would be removed. If a room has been occupied for some time 

 by persons suffering with a germ disease, bacteria may be 

 distributed through the room, on the floor, ceilings, curtains, 

 etc., and other people who come to live in the room later will 

 be likely to become infected. If we can treat the room in such 

 a way as to destroy the bacteria, it may be rendered safe. This 

 we call disinfection. To sterilize any object means to kill all 

 organisms -whether disease-producing or not. 



The simplest method of sterilizing is by the use of heat. 

 All bacteria are killed by sufficient heat, and nearly all that 

 are liable to produce disease in man are killed by the heat 

 of boiling water. Therefore anything that can be boiled, 

 like water or milk, or anything that can be treated in boiling 

 water, like towels or sheets, can be easily sterilized by this 

 means. Water and milk are frequently treated in this way 

 when there is any suspicion of their infection. When one is 

 uncertain as to how to sterilize or disinfect suspected articles 

 it is wisest to follow the advice of health officers, whose 

 duty it is to know these methods and their practical appli- 

 cations. 



