encourage marriage, it is probable that the custom of early
marriages will continue till the population of the country has
gone beyond the increased produce, and sickly seasons appear to
be the natural and necessary consequence. I should expect,
therefore, that those countries where subsistence was increasing
sufficiency at times to encourage population but not to answer
all its demands, would be more subject to periodical epidemics
than those where the population could more completely accommodate
itself to the average produce.

An observation the converse of this will probably also be
found true. In those countries that are subject to periodical
sicknesses, the increase of population, or the excess of births
above the burials, will be greater in the intervals of these
periods than is usual, caeteris paribus, in the countries not so
much subject to such disorders. If Turkey and Egypt have been
nearly stationary in their average population for the last
century, in the intervals of their periodical plagues, the births
must have exceeded the burials in a greater proportion than in
such countries as France and England.

The average proportion of births to burials in any country
for a period of five to ten years, will hence appear to be a very
inadequate criterion by which to judge of its real progress in
population. This proportion certainly shews the rate of increase
during those five or ten years; but we can by no means thence
infer what had been the increase for the twenty years before, or
what would be the increase for the twenty years after. Dr Price
observes that Sweden, Norway, Russia, and the kingdom of Naples,
are increasing fast; but the extracts from registers that he has