strength which should have been kept for the work of real life. Habits are
often formed in youth which entail weakness and poverty upon manhood, and
are a cause of lifelong regret. The use of a strained limb may permanently
damage it. Some silly feat of strength may produce an irreparable injury.
A thoughtless hour of reading by twilight may impair the sight for life. A
terrible accident may happen, and a dear friend perish before our eyes,
while we stand by powerless to render the assistance we could so easily
give did we "only know what to do." The thousand little hints which may
save or lengthen life, may repel or abate disease, and the simple laws
which regulate our bodily vigor, should be so familiar that we may be
quick to apply them in an emergency. The preservation of health is easier
than the cure of disease. Childhood can not afford to wait for the lesson
of experience which is learned only when the penalty of violated law has
been already incurred, and health irrevocably lost.

NATURE'S LAWS INVIOLABLE.--In infancy, we learn how terribly Nature
punishes a violation of certain laws, and how promptly she applies the
penalty. We soon find out the peril of fire, falls, edged tools, and the
like. We fail, however, to notice the equally sharp and certain
punishments which bad habits entail. We are quick to feel the need of
food, but not so ready to perceive the danger of an excess. A lack of air
drives us at once to secure a supply; foul air is as fatal, but it gives
us no warning.

Nature provides a little training for us at the outset of life, but leaves
the most for us to learn by bitter experience. So in youth we throw away
our strength as if it were a burden of which we desire to be rid. We eat
anything, and at any time; do anything we please, and sit up any number of
nights with little or no sleep. Because we feel only a momentary
discomfort from these physical sins, we fondly imagine when that is gone