and that the fecundity in towns of between
3000 and 4000 inhabitants is at least as great as the average fecundity
of the kingdom. The average fecundity of a marriage in towns of fewer
than 3000 inhabitants is about four; in towns of between 3000 and 4000
inhabitants it is 3.60. Now, the average fecundity of England, when it
contained only 160 inhabitants to a square mile, and when, therefore,
according to the new law of population, the fecundity must have been
greater than it now is, was only, according to Mr Sadler, 3.66 to a
marriage. To proceed,--the fecundity of a marriage in the English towns
of between 4000 and 5000 inhabitants is stated at 3.56. But, when
we turn to Mr Sadler's table of counties, we find the fecundity of a
marriage in Warwickshire and Staffordshire rated at only 3.48, and in
Lancashire and Surrey at only 3.41.

These facts disprove Mr Sadler's principle; and the fact on which he
lays so much stress--that the fecundity is less in the great towns than
in the small towns--does not tend in any degree to prove his principle.
There is not the least reason to believe that the population is more
dense, ON A GIVEN SPACE, in London or Manchester than in a town of 4000
inhabitants. But it is quite certain that the population is more dense
in a town of 4000 inhabitants than in Warwickshire or Lancashire. That
the fecundity of Manchester is less than the fecundity of Sandwich or
Guildford is a circumstance which has nothing whatever to do with Mr
Sadler's theory. But that the fecundity of Sandwich is greater than the
average fecundity of Kent,--that the fecundity of Guildford is greater
than the average fecundity of Surrey,--as from his own tables appears to
be the case,--these are facts utterly inconsistent with his theory.

We need not here examine why it is that the human race is less fruitful
in great cities than in small towns or in the open country. The fact has
long been notorious. We are inclined to attribute it to the same causes
which tend to abridge human life in great cities,--to general sickliness
and want of tone, produced by close air and sedentary employments. Thus
far, and thus far only, we agree with Mr Sadler, that, when population
is crowded together in such masses that the general health and energy of
the frame are impaired by the condensation, and by the habits attending
on the condensation, then the fecundity of the race diminishes. But this
is evidently a check of the same class with