, of which old age ought constantly
to avail itself.

Saddle-leather is in some respects even preferable to sole-leather.
The principal objection to it is of a financial character. But you
may be sure that Bacon and Sydenham did not recommend it for
nothing. One's hepar, or, in vulgar language, liver,--a ponderous
organ, weighing some three or four pounds,--goes up and down like
the dasher of a churn in the midst of the other vital arrangements,
at every step of a trotting horse. The brains also are shaken up
like coppers in a money-box. Riding is good, for those that are
born with a silver-mounted bridle in their hand, and can ride as
much and as often as they like, without thinking all the time they
hear that steady grinding sound as the horse's jaws triturate with
calm lateral movement the bank-bills and promises to pay upon which
it is notorious that the profligate animal in question feeds day
and night.

Instead, however, of considering these kinds of exercise in this
empirical way, I will devote a brief space to an examination of
them in a more scientific form.

The pleasure of exercise is due first to a purely physical
impression, and secondly to a sense of power in action. The first
source of pleasure varies of course with our condition and the
state of the surrounding circumstances; the second with the amount
and kind of power, and the extent and kind of action. In all forms
of active exercise there are three powers simultaneously in
action,--the will, the muscles, and the intellect. Each of these
predominates in different kinds of exercise. In walking, the will
and muscles are so accustomed to work together and perform their
task with so little expenditure of force, that the intellect is
left comparatively free. The mental pleasure in walking, as such,
is in the sense of power over all our moving machinery. But in
riding, I have the additional pleasure of governing another will,
and my muscles extend to the tips of the animal's ears and to his
four hoofs, instead of stopping at my hands and feet. Now in this
extension of my volition and my physical frame into another animal,
my tyrannical instincts and my desire for heroic strength are at
once gratified. When the horse ceases to have a will of his own
and his muscles require no special attention on your part, then you
may live on horseback as Wesley did, and write sermons or take
naps, as you like. But you will observe, that, in riding on
ho