564 POPULAR SCIENCE MONTHLY. 



the gale be sufficiently furious and the billows sufficiently huge. As 

 it is necessary to admit that even one attack of smallpox does not 

 confer absolute immunity against a second, seeing that some men 

 have had two and even more of such attacks in a lifetime, equally 

 must it be admitted that vaccinated persons, and even many times re- 

 vaccinated persons, have had attacks of smallpox. In ordinary seasons 

 when smallpox is not prevalent a larger protection is conferred by 

 vaccination than that conferred by the lightning-rod upon the dweller 

 beneath the roof above which it rises. But in seasons of epidemic in- 

 fluence, even though the epidemic be as mild as that which furnishes 

 the theme of this paper, such an influence is appreciable and in many 

 cases highly effective. At these times those who previously were in- 

 capable of being vaccinated (even the vaccini culturists occasionally find 

 heifers which cannot be made to serve as vaccinifers) are inoculated 

 with ease; at such times also vaccination can be made effective even 

 after the onset of unmistakable symptoms of smallpox; at such times 

 also even those who have had smallpox can be vaccinated, and that 

 after the recent establishment of convalescence. The ardent advocates 

 of the position that the mild epidemic through which this country has 

 just passed was not one of smallpox pointed with what seemed to them 

 convincing force to the fact that they had successfully vaccinated 

 the victims of the disease immediately after recovery. But the argu- 

 ment was without force. The skin of a person convalescent from 

 smallpox is in an exceedingly irritable state and readily is excited to 

 the production of local symptoms at the point where the needle of the 

 vaccinator has been at play. It has to be borne in mind that the 

 actual introduction of a disease by inoculation is a far more rigid test 

 than mere exposure to a volatile poison, the kind of exposure tlirough 

 which, as a rule, smallpox is acquired. What physician, for example, 

 would dare to inoculate a patient with the virus of smallpox after 

 the most classically perfect vaccination? He would be held criminally 

 liable for the result if, as might happen, in this way he should dissemi- 

 nate the disease throughout the community in which he lived. 



But the spurious results cited of vaccination of convalescents from 

 modified smallpox prove nothing. Even highly typical results would 

 not disprove the fact of a previous attack of modified or unmodified 

 smallpox. It has been shown that both the vaccination process and 

 the variolous process may pursue their career at one and the same 

 time in the same body. But Dr. Mosely, of Kentucky, put the 

 question to a decisive test last year when he vaccinated three negroes, 

 each convalescent from smallpox, immediately on his release from 

 quarantine. Each subsequently exhibited classical results of successful 

 vaccination in due time and course. 



Eespecting the enormous value of vaccination to the human race, it 



