VOL. LXV.] PHILOSOPHICAL TRANSACTIONS. - " .flSl 



there are no years of life, in which so many of a given number die, as the first 

 3 or 4 years. Till the age of 5, human life, like a fire beginning to burn, is 

 very feeble ; and in some situations more than 4-, and in others, a 3d or 4th of 

 all that are born die before that age. After this, life grows less and less preca- 

 rious, till it acquires its utmost vigour at 10 or 15 ; and of the living at this age, 

 not above 1 in 70 or 80 dies annually in the worst situations ; and in the best 

 situations, not above 1 in 150 or l6o. After 15, life declines, and continues 

 to do so more and more, till it becomes quite extinct in old age. If therefore, 

 in any situation, the inhabitants consist more of persons in mature life, and yet 

 die faster, it must be owing to some particular causes of mortality that operate 

 there. This is the case in all towns where any observations have been made. 

 Manchester, in particular, is not only kept up, but increases fast, by removals 

 to it of persons in the prime of life. The country round it increases likewise ; 

 but it is by an excess of the births above the deaths ; that is, by accessions to it 

 of children in the veiy feeblest part of life. This ought to raise the proportion 

 of annual deaths to inhabitants in the country, much above the same proportion 

 in the town ; but, instead of this, it is near one half lower. 



In order however to put this matter out of all doubt, it appears in fact, from 

 the accounts furnished by Dr. Percival, that the number of inhabitants in the 

 periods of life when mankind die fastest, that is, in the first and last stages of 

 life, is considerably less in the town of Manchester than in the adjacent country. 

 The number of inhabitants in the town, under 15 and above 50, is 13467 ; in 

 the country, 7305. And the whole number is, in the town, 27246 ; in the 

 country, 13786. In the town therefore the inhabitants, in the first and last 

 stages of life, do not make half the whole number ; but in the country, they 

 make considerably more than half. At Ackworth likewise, in Yorkshire, the 

 inhabitants under 15 and above 50 are more than half the whole number; and 

 the same is true at Hale near Altringham, at Horwich, at Darwen near Black- 

 bum in Lancashire, and at Cockey Moor near Bolton, in the same county, and 

 yet in some of these places it appears, that not a 6oth part of the inhabitants die 

 annually. At Stockholm, in 1763, the inhabitants under the age of 5, were 

 only a 12th; above 70, only a 46th part of the whole number. But in all 

 Sweden, the number under 5 was a 7th ; and above 70, near the 32d part of 

 all the inhabitants : and yet 35 die in the town to 19 in the whole kingdom. This 

 may be easily deduced from Mr. Wargentin's tables in the Collection Academique. 

 To the accounts which give the proportion of inhabitants to annual deaths, 

 so high as 50 or 60 to 1, u .las been further objected, that if true, it must 

 follow, that in such situations half the inhabitants must live to 50 or 60 years of 

 age. But were this a right inference, there would be nothing in it incredible. 

 For though in most cities one half die in the first 2 or 3 years after birth ; yet 



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