The author goes on to remark, "that the decline in the mortality is
even more striking in our cities than in our rural districts. While the
metropolis has extended itself in all directions, and multiplied its
inhabitants to an enormous amount,--in other words, while the seeming
sources of its unhealthiness have been largely augmented, it has
actually become more friendly to health." In the middle of the last
century, the annual mortality was about 1 in 20. By the census of 1821,
it appeared as 1 in 40: so that in the space of seventy years, the
chances of existence are exactly _doubled_ in London,--a progress
and final result, adds the author, without a parallel in the history of
any other age or country. The high rate of mortality in London about the
year 1750, exceeding considerably that of former years, has been
attributed to the great, abuse of spirituous liquors, which were then
sold without the very necessary check of high duties. One of the results
of these statistical investigations which, _a priori_, we should
least have been prepared for, is the uncommon healthiness of Manchester.
The rate of mortality there at the present time does not appear to
exceed 1 in 74.

The statistics of the sexes afford some curious results. The relative
numbers of the sexes are the same in all parts of the world,--namely,
at birth, twenty-one males to twenty females, but as the mortality
among males during infancy exceeds that of females, the sexes at the
age of fifteen are nearly equal. A late French writer, M. Giron, thinks
himself warranted in the opinion, that agricultural pursuits favour an
increase in the male, while commerce and manufactures encourage the
female population. There exists throughout the world considerable
variety in the proportion of births to marriages, but, upon an average,
we may state it at about four to one. It has been uniformly found,
however, that improvements in the public health are attended by a