GENERAL CONCLUSIONS 253 



insects, there is absolutely nothing to be feared in night 

 air. While vigorous health is a protection against some 

 diseases (tuberculosis), it is far less efficient against others 

 (smallpox). 



It should always be borne in mind that contagious 

 diseases are real things, and not the result of imagination. 

 They are produced in our bodies by the growth of certain 

 microscopic animals and plants in our blood, muscles, or 

 elsewhere. They cannot be warded off by simply disbe- 

 lieving in their existence, and the sooner the housewife 

 learns that a contagious disease is due to distinct living 

 beings which are transported from one person to another 

 and live as parasites in the patient, the sooner will she be 

 in a position to protect her family from the spread of 

 contagion. 



General Conclusions 



Each type of infectious disease must be fought in its 

 own way. The so-called children's diseases are so decidedly 

 contagious that isolation alone is capable of preventing 

 their distribution. Of the adult diseases, however, the 

 most serious may be largely checked by proper means. 

 Smallpox must be fought with vaccination and isolation, 

 diphtheria by antitoxin and isolation, typhoid fever by 

 a guard placed over the water and the milk supplies and 

 by fighting flies, malaria by destroying the breeding places 

 of mosquitoes and protecting the body from mosquito bites. 



Of all diseases, however, tuberculosis is most widespread 

 and demands most attention. The common form of this 

 disease is consumption, but the bacteria may attack other 



