CHAPTER VII 

 STERILIZATION 



Introduction. By sterilization is meant the process by 

 which the vitality of all the microorganisms in or upon an 

 object are destroyed, and an object which is entirely free 

 from all living microorganisms and their spores is described 

 as sterile. 



Sterilization has come to be confounded with disinfection. 

 By disinfection is meant a process which insures the destruc- 

 tion of those living forms which have the power of producing 

 an infection, or disease, and may or may not be complete in 

 the sense of sterilization. 



In the laboratory it is customary to speak of sterilization as 

 the process which frees a substance from bacteria, but does 

 not change its composition or interfere with its nutritive 

 quality. That is, it renders it germ-free but not barren. This 

 is usually accomplished by a physical agent. Disinfection has 

 come to imply a change in composition, due to the fact that 

 chemicals are usually employed in the process. While the 

 above terms are not strictly correct, their use is convenient. 

 Both sterilization and disinfection may be accomplished by 

 either physical or chemical agents. 



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