Neglect is the danger of the country; the peril of the city is in living too fast.  All mental excitement acts as a stimulant, and, like all stimulants, debilitates when taken in excess.  This explains the unnatural strength and agility of the insane, always followed by prostration; and even moderate cerebral excitement produces similar results, so far as it goes.  Quetelet discovered that sometimes after lecturing, or other special intellectual action, he could perform gymnastic feats impossible to him at other times.  The fact is unquestionable; and it is also certain that an extreme in this direction has precisely the contrary effect, and is fatal to the physical condition.  One may spring up from a task of moderate mental labor with a sense of freedom like a bow let loose; but after an immoderate task one feels like the same bow too long bent, flaccid, nerveless, all the elasticity gone.  Such fatigue is far more overwhelming than any mere physical exhaustion.  I have lounged into the gymnasium, after an afternoon’s skating, supposing myself quite tired, and have found myself in excellent condition; and I have gone in after an hour or two of some specially concentrated anxiety or thought, without being aware that the body was at all fatigued, and found it good for nothing.  Such experiences are invaluable; all the libraries cannot so illustrate the supremacy of immaterial forces.  Thought, passion, purpose, expectation, absorbed attention even, all feed upon the body’s powers; let them act one atom too intensely or one moment too long, and this wondrous physical organization finds itself drained of its forces to support them.  It does not seem strange that strong men should have died by a single ecstasy of emotion too convulsive, when we bear within us this tremendous engine whose slightest pulsation so throbs in every fibre of our frame.

The relation between mental culture and physical powers is a subject of the greatest interest, as yet but little touched, because so few of our physiologists have been practical gymnasts.  Nothing is more striking than the tendency of all athletic exercises, when brought to perfection, to eliminate mere brute bulk from the competition, and give the palm to more subtile qualities, agility, quickness, a good eye, a ready hand,—­in short, superior fineness of organization.  Any clown can learn the military manual exercise; but it needs brain-power to drill with the Zouaves.  Even a prize-fight tests strength less than activity and “science.”  The game of base-ball, as played in our boyhood, was a simple, robust, straightforward contest, where the hardest hitter was the best man; but it is every year becoming perfected into a sleight-of-hand, like cricket; mere strength is now almost valueless in playing it, and it calls rather for the qualities of the billiard-player.  In the last champion-match at Worcester, nearly the whole time was consumed in skilful feints and parryings, and it took five days to make fifty runs.  And these same characteristics mark gymnastic exercises above all; men of great natural strength are very apt to be too slow and clumsy for them, and the most difficult feats are usually done by persons of comparatively delicate physique and a certain artistic organization.  It is this predominance of the nervous temperament which is yet destined to make American gymnasts the foremost in the world.