The Preservation of Health 295 



THE PREVENTION AND RESTRICTION OF DISEASE 



459. Means to avert Danger of Disease. From the 

 preceding pages we have learned many of the simplest 

 principles which underlie the maintenance of good health. 

 Wholesome food, pure air, proper clothing, cleanliness, 

 and physical exercise all play their part in maintaining 

 good health and in preventing disease. 



We have now to consider other means used to avert 

 danger of disease. The whole question strictly concerns 

 public sanitation, which does not come within the scope of 

 this book. It is well, however, for every intelligent person 

 to understand a few of the simplest facts of so important 

 a subject and one which affects the welfare of every 

 community. 



460. Vaccination, Isolation, and Disinfection, One of 

 the most familiar means to prevent disease is the use of 

 vaccination for smallpox. That is, persons who are vacci- 

 nated are immune, as it is called, from smallpox, or have 

 it in a milder form. 



The diphtheria antitoxin is now quite generally used to 

 secure immunity from this dangerous disease. 



One very common safeguard against the spread of con- 

 tagious diseases is isolation. The patients, and often the 

 family, are isolated from other people ; a rigid system of 

 nursing is instituted, a placard is placed upon the house, 

 the premises are watched, and other familiar means of isola- 

 tion are employed. 



Disinfection is universally recognized as a most efficient 

 and practical means to prevent the spread of disease. 



461. A Few Words explained. Some substances kill 

 bacteria and are known as germicides; other substances 

 prevent the development of bacteria and resulting septic 



