VOL. XXXII.] PHILOSOPHICAL TRANSACTIONS. 5l J 



Out of this number, the opposers of inoculation affirm, that 2 persons died 

 of the inoculated small-pox ; the favourers of this practice maintain, that their 

 death was occasioned by other causes. If, to avoid dispute, these 2 be allowed 

 to have died of inoculation, we must estimate the hazard of dying of the ino- 

 culated small-pox, as far as can be collected from our own experience, to be 

 that of 2 out of ]82, or one out of Ql. 



The Rev. Mr. Mather, in a letter dated March 10, 17 '21, from Boston iu 

 New England, gives an account, that of near 300 inoculated there, 5 or d died 

 on it or after it, but by other diseases and accidents; chiefly from having taken 

 the infection in the common way by inspiration, before it could be given them 

 in this way of transplantation. 



If we allow 5 out of these 300 to have died of the small-pox by inoculation, 

 notwithstanding what Mr. Mather has said of their dying by other accidents or 

 diseases; the hazard of inoculation will thence be determined to be that of 1 in 

 about 6o. , But here it must be observed, that by all the accounts from New 

 England, the operators there appear not to have been so cautious in the choice 

 of their subjects, as here in England. For Mr. Mather tells us, that the per- 

 sons inoculated were young and old, from 1 year to 70, weak and strong ; 

 and by other relations we are informed, that women with child, and others 

 even in childbed, underwent the operation. Apparently the greatness of 

 the danger they were in, from the infection in the natural way, which 

 then raged among them with the utmost fury, made them the more ad- 

 venturous. 



Now to form an estimate of the hazard, which all mankind, one with an- 

 other, are under of dying of the natural small-pox, that, by comparing this 

 with the hazard of inoculation, the public may be enabled to form a judgment, 

 whether the practice of inoculation tends to the preservation of mankind, by 

 lessening the danger to which they are otherwise liable. With this view I have 

 consulted the yearly bills of mortality, as far back as the year 1667, being the 

 year after the plague and the fire of London, comprehending to the present 

 time the space of 56 years, from 42 of which I have given extracts in the 2 

 following tables. 



The first of these takes in the first 20 years, distinguishing for every year the 

 total number of burials, and likewise the number that died of the small-pox, in 

 2 separate columns. The 3d column shows how many died of the small-pox 

 out of every lOOO that were buried; and the 4th column represents the pro- 

 portion between those that died of the small-pox, and the whole number of 

 burials, by the nearest vulgar fraction, having always i for the numerator. 



The 2d table gives the last 22 years, after the same manner, and at the bot- 



4 I 2 



