286 THE INVISIBLE WOELD 



tient gets well, the antitoxine, or its effect, remains 

 in the body and protects it against a second at- 

 tack. The individual therefore has the disease but 

 once. Afterwards he is immune. 



Now, it is found that a light form of the disease 

 renders the body immune against the second attack 

 just as effectually as a severe form. Hence a way 

 is discovered to produce the disease in a light form. 

 A bit of the virus is introduced to the circulation 

 by inoculation. The person inoculated has the dis- 

 ease in its light form, a mere touch of the dis- 

 ease. But this makes him safe against a second 

 attack. 



This is vaccination, Nature's preventive. The 

 entire process is natural. Nature manufactures 

 the virus. Nature produces the mild form of the 

 disease. Nature prevents the recurrence of the 

 disease. 



During the hundred and twenty-five years since 

 the discovery of this process by Dr. Jenner, by vac- 

 cinating for the smallpox, no doubt, more than a 

 hundred and twenty-five million lives have been 

 saved. 



Of course, in case of a disease which comes only 

 in a mild form, like the chicken pox, vaccination 

 is no good. But in case of threatened epidemics 

 of a severe disease, vaccination of those more spe- 

 cially exposed is great good. 



For several of the severer diseases vaccines have 

 already been discovered and applied with great suc- 

 cess. 



