VOL. XXXII.] PHILOSOPHICAL TRANSACTIONS. 6l3 



By these tables it appears, that upwards of 7 per cent, or somewhat more 

 than a 1 4th part of mankind, die of the small-pox ; and consequently the 

 hazard of dying of that distemper, to every individual born into the world, is 

 at least that of 1 in 14. And that this hazard increases after the birth, as the 

 child advances in age, will appear from what follows. 



From this estimate it is demonstrable, that in the case of persons actually 

 having the small-pox, the hazard that they run, one with another, of dying of 

 that distemper, is greater than that of I in 14 ; or, which is the same thing, 

 there must be fewer than 13, that recover, for 1 that dies of the small-pox. 

 For since -^ part of mankind die of the small-pox, and the other 13 

 parts die of other diseases; if these 13 have all had the small- pox, and recovered 

 from it before they fell ill of those other diseases of which they died, then just 

 13 will have recovered from the small-pox, for one that dies of that distemper: 

 but, as it is notorious, that great numbers, especially of young children, die of 

 other diseases, without ever having the small-pox, it is plain, that fewer than 

 13 must recover from this distemper, for 1 that dies of it. 



To determine exactly how many of these 13 parts of mankind, die without 

 having the small-pox, is a very difficult task : but it is easy to see, that a con- 

 siderable deduction is to be made from them. In the first place, the 2 articles 

 of stillborn and abortive children, which are put into the yearly bills, as part of 

 the number of burials, are unquestionably to be deducted. 



With these 2, may be joined the following heads, which, by the best infor- 

 mation I can procure, comprehend only very young children, or at most not 

 above 1 or 2 years of age. Overlaid, chrysoms and infants, convulsions, 

 horseshoehead, headmoldshot, teeth, water in the head, worms, rickets, liver- 

 grown, chin-cough, and hooping-cough, which articles in the yearly bills for 

 22 vears last past, amount at a medium to 386 in each 1000, of the whole 

 number of burials. 



It is true indeed, that probably some small part of these must have gone 

 through the small-pox, and therefore ought not to be deducted out of the ac- 

 count : but then on the other hand, as it is certain that of the remaining .VttV 

 of mankind, that are above 1 or 2 years of age, there are great numbers that 

 never have the small-pox, it will I presume be judged to be no unequal sup- 

 position, if I suppose all that are contained under the heads abovementioned, 

 to have missed that distemper, when by way of compensation, I allow all the 

 remainder of mankind to undergo it; which concession is so large, that it will 

 abundantly make up for what I assume too much in the former supposition. 



Allowing therefore, that out of every 1000 children that are born, 386 die 

 under 1 or 2 years of age, without having the small -pox, and 72 do some time 



