2i8 INFECTION AND IMMUNITY 



taken. On the contrary, the history of vaccination and of small- 

 pox in the United States Army suffices in itself to demonstrate 

 that protection from the disease is proportioned to the care with 

 which vaccination is performed. . . . Although this disease 

 has prevailed in many parts of the United States during the past 

 fifteen years (1883 to 1897), and frequently with epidemic vio- 

 lence, among the civil population in the immediate vicinity of 

 military posts, there occurred only 20 scattered cases, of which 4 

 were fatal, in a mean strength of 25,000 men." 



The cases which occur in various parts of the coun- 

 try, from time to time, are for the most part among 

 unvaccinated individuals. For example, in the city 

 of Chicago, the Bulletin of the Health Department 

 for the month ending May 31, 1903, says : 



" During the month forty- five cases of smallpox 

 were discovered and removed to the Isolation 'Hos- 

 pital. Of these thirty-nine never had been vaccinated ; 

 six had old, imperfect marks, said to be from vaccina- 

 tion in childhood. Fifteen were unvaccinated child- 

 ren under six years of age." 



It is unnecessary to give any further facts in support 

 of the protective value of vaccination, which, since 

 the discovery of Jenner in 1796, has been established 

 by unimpeachable statistical data in all parts of the 

 civilised world. But there are certain persons whose 

 minds are not penetrated by the logic of facts, or who 

 have not taken the pains to make themselves familiar 

 with these facts, who still oppose vaccination on the 

 ground that it has no value as a preventive measure. 



