omotes health. Man was never intended to be a
running or a jumping machine. In mental work, variety should be
introduced. New work calls into play fresh portions of the brain, and
secures repose for those parts which have become exhausted. Idleness
should be avoided by all. Men should never retire from business as long
as they enjoy a fair degree of health. Idleness and inactivity are
opposed to nature.

9. The average length of time which a person ought to sleep is eight
hours out of the twenty-four, and, as a rule, those who take this amount
enjoy the best health. The most favorable time for sleep is between the
hours of 10 P.M. and 6 A.M. All excitement, the use of stimulants, and
excessive fatigue tend to prevent sleep. Sleeping rooms should be well
ventilated, and the air maintained at a equable temperature of as near
60 deg. Fahr. as possible. An inability to sleep at the proper time, or a
regular inclination to sleep at other than the natural hours for it, is
a certain indication of errors of habit, or of nervous derangement.

10. Prominent among all other measures for the maintenance of Health, is
personal cleanliness. Activity in the functions of the skin is essential
to perfect health, and this can only be secured by thoroughly bathing
the entire body. Strictly, a person should bathe once every twenty-four
or forty-eight hours. The body should be habituated to contact with cold
water at all season of the year, so that warm water may not become a
necessity. The simplest and most convenient bath, is the ordinary
sponge-bath. An occasional hot-air, or Turkish bath, exerts a very
beneficial influence. It cleans out the pores of the skin and increases
its activity.

11. The emotions and the passions exert a powerful influence over the
physical organism. It is important, therefore, that they be held under
restraint by the reasoning faculties. This rule applies equally to joy,
fear, and grief; to avarice, anger, and hatred; and, above all, to the
sexual passion. They are a prolific source of disease of the nervous
system, and have caused the dethronement of some of the most gifted
intellects.

* * * * *

PART III.

RATIONAL MEDICINE.

CHAPTER I.

THE PROGRESS OF MEDICINE.

During the last half century a great change has taken place in the
treatment of disease. Medicine has advanced with rapid strides, from the
narrow limits of mere empiricism, to the broader re