by the presence of an
unclean skin. It is also a fact that uncleanly people are more liable to
take cold than those who bathe often.

The importance of cleanliness would thus seem too apparent to need special
mention, were it not that the habit is so much neglected. The old and
excellent definition that dirt is suitable matter, but in the wrong place,
suggests that the place should be changed. This can be done only by
regular habits of personal cleanliness, not only of the skin, the hair,
the teeth, the nails, and the clothing, but also by the rigid observance
of a proper system in daily living.

246. Baths and Bathing. In bathing we have two distinct objects in
view,--to keep the skin clean and to impart vigor. These are closely
related, for to remove from the body worn-out material, which tends to
injure it, is a direct means of giving vigor to all the tissues. Thus a
cold bath acts upon the nervous system, and calls out, in response to the
temporary abstraction of heat, a freer play of the general vital powers.
Bathing is so useful, both locally and constitutionally, that it
should be practiced to such an extent as experience proves to be
beneficial. For the general surface, the use of hot water once a week
fulfills the demands of cleanliness, unless in special occupations.
Whether we should bathe in hot or cold water depends upon circumstances.
Most persons, especially the young and vigorous, soon become accustomed to
cool, and even cold water baths, at all seasons of the year.

The hot bath should be taken at night before going to bed, as in the
morning there is usually more risk of taking cold. The body is readily
chilled, if exposed to cold when the blood-vessels of the skin have been
relaxed by heat. Hot baths, besides their use for the purposes of
cleanliness, have a sedative influence upon the nervous system, tending to
allay restlessness and weariness. They are excellent after severe physical
or mental work, and give a feeling of restful comfort like that of sleep.

[Illustration: Fig. 105.--Epithelial Cells from the Sweat Glands. The
cells are very distinct, with nuclei enclosing pigmentary granulations
(Magnified 350 times)]

Cold baths are less cleansing than hot, but serve as an excellent
tonic and stimulant to the bodily functions. The best and most convenient
time for a cold bath is in the morning, immediately after rising. To the
healthy and vigorous, it is, if taken at this time, with proper
pre