View report page

67
from Small.Pox, that is to say, the proportion of deaths to the
number of persons living, we are met with the difficulty of the
population not being exactly known. As already stated, it has
been calculated that the population in 1685 was 530,000. On
the basis of this datum, the average yearly death.rate of, or
mortality from Small.Pox in the ten years around this date,
namely, in the years 1681.90, was 3.139 per thousand; the
mortality from all causes of death being 42.2 per thousand.
Similarly in the ten years 1746.55, on the calculation that the
population in 1750 was 653,900, the yearly mortality from SmallPox
was 3.044; that of deaths from all causes 35.5 per thousand.
Taking the same calculations as to population we find that in
years when the deaths from Small.Pox were very high, the
mortality from Small.Pox, both in the seventeenth and eighteenth
centures, was frequently 3, 4, 5, or even more per thousand.
Even if we take the years in the eighteenth century in which the
returns of deaths from Small.Pox were the lowest, viz., 1702,
1753, 1782, we find, still using the above calculations, the mortality
from Small.Pox o.6, 1.2, and 1.o respectively, and in 1797, using
the census of 1801, the death.rate was 0.7. And in most of the
years of that century the mortality from Small.Pox was either
not far below, or very distinctly above, 2 per thousand. All this
means, even when every allowance is made for the insecurity of
the calculations, that the mortality from Small.Pox in London
was, during the eighteenth century, very high. This is a broad
conclusion which may be considered as definitely proved.
Thus Daniel Bernouilli, writing in 1760.5, takes as one of
the bases of his circulation the datum (arrived at by means of
various records in various places) that Small.Pox carries off the
thirteenth or fourteenth part of each generation ; or in other
words, that the deaths from Small.Pox are about one.thirteenth
or one.fourteenth of the deaths from all causes. The same
author uses another datum obtained in a similar way, namely,
that the eighth or the seventh part of those attacked die of it.
From this, it follows that something like 40 per cent. of those