lair, eight. These were the _theories_ of
men who were all eminent for their learning, and most of them for their
piety. How far their _practice_ corresponded with their theories, we are
not, in every instance, told.

But to come to the practice of several persons who have been
distinguished in the world. General Elliot, one of the most vigorous men
of his age, though living for his whole life on nothing but vegetables
and water, and who at sixty-four had scarcely begun to feel the
infirmities of old age, slept but four hours in twenty-four. Frederick
the Great of Prussia, and the illustrious British surgeon, John Hunter,
slept but five hours a day. Napoleon Bonaparte, for a great part of his
life, slept only four hours; and Lord Brougham is said to require no
more. Others, in numerous instances, require but six hours. But there
are others still, who consume eight.

The conclusion--in my own mind--is, that with a good constitution and
active habits, men may habituate themselves to very different quantities
of sleep. Still I think that six hours are little enough for most
persons; and if a child, on arriving at maturity, is not inclined to
sleep much longer than that, I should not regard him as wasting time.
Most persons, it appears to me, require six hours of sound sleep in
twenty-four;--I mean between the ages of twenty and seventy.

Macnish is the most liberal modern writer I am acquainted with, in his
allowance of time for sleep. Speaking of the wants of adults he
says--"No person who passes only eight hours in bed can be said to waste
his time in sleep." Yet he obviously contradicts himself on the very
same page; for he says expressly, that when a person is young, strong
and healthy, an hour or two less may be sufficient. But an hour or two
less than eight hours reduces the amount to seven or six hours. And
taking the whole period of life, to which he probably refers--say from
eighteen to forty--into consideration, there is a very considerable
difference between six hours and eight hours a day. If six hours are
"sufficient," it cannot be right to sleep eight hours.

Let us here make a few estimates. If six hours are sufficient for sleep
between the ages of eighteen and forty, he who sleeps eight hours a day,
actually loses 16,060 hours--equal to nearly two whole years of life, or
about two years and three quarters of time in which we are usually
awake. This, in the meridian of life, is not a small waste. Permit i