people of America is principally owing to
emigration from Europe, states this fact in the plainest manner:

"Nothing is more certain, than that emigration is almost universally
supplied by 'single persons in the beginning of mature life;' nor,
secondly, that such persons, as Dr Franklin long ago asserted, 'marry
and raise families.'

"Nor is this all. It is not more true, that emigrants, generally
speaking, consist of individuals in the prime of life, than that 'they
are the most active and vigorous' of that age, as Dr Seybert describes
them to be. They are, as it respects the principle at issue, a select
class, even compared with that of their own age, generally considered.
Their very object in leaving their native countries is to settle in
life, a phrase that needs no explanation; and they do so. No equal
number of human beings, therefore, have ever given so large or rapid an
increase to a community as 'settlers' have invariably done."

It is perfectly clear that children are more numerous in the back
settlements of America than in the maritime states, not because
unoccupied land makes people prolific, but because the most prolific
people go to the unoccupied land.

Mr Sadler having, as he conceives, fully established his theory of
population by statistical evidence, proceeds to prove, "that it is
in unison, or rather required by the principles of physiology." The
difference between himself and his opponents he states as follows:--

"In pursuing this part of my subject, I must begin by reminding the
reader of the difference between those who hold the superfecundity of
mankind and myself, in regard to those principles which will form the
basis of the present argument. They contend, that production precedes
population; I, on the contrary, maintain that population precedes, and
is indeed the cause of, production. They teach that man breeds up to the
capital, or in proportion to the abundance of the food, he possesses: I
assert, that he is comparatively sterile when he is wealthy, and that
he breeds in proportion to his poverty; not meaning, however, by that
poverty, a state of privation approaching to actual starvation, any more
than, I suppose, they would contend, that extreme and culpable excess
is the grand patron of population. In a word, they hold that a state
of ease and affluence is the great promoter of prolificness. I maintain
that a considerable degree of labour, and even privation, is a more
efficient cau