ting to mental
exercise, and the development and culture of the mind and brain. It is a
law of the animal economy that two classes of functions can not be
called into vigorous action at the same time without one or the other,
or both, sooner or later sustaining injury. Hence the important rule
never to enter upon continued mental exertion or to rouse deep feeling
immediately after a full meal, otherwise the activity of the brain is
sure to interfere with that of the stomach, and disorder its functions.
Even in a perfectly healthy person, unwelcome news, sudden anxiety, or
mental excitement, occurring after eating, will put an entire stop to
digestion, and cause the stomach to loathe the sight of food. In
accordance with this rule, we learn by experience that the very worst
forms of indigestion and nervous depression are those which arise from
excessive mental application, or turmoil of feeling and distraction of
mind, conjoined with unrestrained indulgence in the pleasures of the
table. In such circumstances, the stomach and brain react upon and
disturb each other, till all the horrors of nervous disease make their
unwelcome appearance, and render life miserable. The tendency to
inactivity and sleep, which besets most animals after a full meal, shows
repose to be, in such circumstances, the evident intention of Nature.
The bad effects of violating this rule, although not in all cases
immediately apparent, will most assuredly be manifest at a period less
or more remote.

Dr. Caldwell, who has devoted much time and talent to the diffusion of
sound physiological information and the general improvement of the race,
and whose opportunities of observation have been very extensive,
expressly states, that dyspepsy and madness prevail more extensively in
the United States than among the people of any other nation. Of the
amount of our dyspeptics, he says, no estimate can be formed; but it is
immense. Whether we inquire in cities, towns, villages, or country
places; among the rich, the poor, or those in moderate circumstances, we
find dyspepsy more or less prevalent throughout the land.

The early part of the day is the best time for severe mental exertion.
Nature has allotted the darkness of night for repose, and for the
restoration by sleep of the exhausted energies of both body and mind. If
study or composition be ardently engaged in toward the close of the day,
and especially at a late hour of the evening, sound and invigora