CHAPTER VIII 

 DISINFECTION 



One of the most important means at our control for the 

 eradication of specific disease is disinfection. By means of 

 suitable disinfectants we may make positively certain the 

 excretions of the sick are so acted upon as to be rendered 

 harmless ; that everything which has been in contact with 

 the patient has been so treated as to be unable to convey 

 disease, and the building occupied by the diseased cases 

 dealt with in such a way that healthy animals can be 

 placed in it without fear of infection. 



Disinfection gives us a sense of security obtained in no 

 other way ; it is quite true there are some diseases where 

 the infective material does not live long apart from the 

 animal body, but there are others where its vitality is 

 remarkable, and it is obvious that to trust to time alone 

 for destroying infection, is both unwise and illogical, when 

 the same end can be obtained in the short space of a few 

 hours. 



Principles of Disinfection. — A disinfectant is an agent 

 either chemical or physical which destroys pathogenic 

 matter ; its destructive action may be required for the eggs 

 of a parasite, or for the remarkably resistant spores of a 

 bacillus. In either case the principle involved is the same, 

 though the selection of the particular disinfectant depends 

 to an extent on the nature of the virus it is intended to 

 destroy. 



There are disease germs which offer little opposition to 

 the action of disinfectants, and others which are most 



396 

 Digitized by Microsoft® 



