n the soles of the feet.

Scattered through the true skin are millions of tiny organs fastened
to the ends of the nerve threads leading to the spinal cord and brain.
These organs tell us when the skin is touched or when it is hot or
cold or is being hurt.

=The Pores and the Sweat Glands.=--On a warm day the skin becomes wet
with a salty fluid called _sweat_ or _perspiration_. This flows from
the tiny holes or pores in the skin. A good magnifying glass will show
these pores arranged in rows on the ridges in the palm of the hand.

From each pore a tube leads down into the true skin to a coiled tube
forming the _sweat gland_ (Fig. 45). Sweat glands are present by the
thousands in the skin of all parts of the body. They give out from
one pint to a gallon of sweat daily. The more we work and the warmer
the weather, the more the sweat flows.

There is a little waste matter carried out of the body by the sweat,
but its chief use is to cool the body. It does this by passing off in
the air and carrying the heat with it. In this way the body is kept
from getting too hot in summer.

=The Color of the Skin.=--In the African race the color of the skin is
black, in the Chinese it is yellowish, while in our race it is nearly
white. The different hues are due to a coloring matter called
_pigment_. This lies in the deep part of the scarfskin. Going out in
the wind and sun causes more pigment to collect, and we say we are
tanned. If the pigment collects in spots, it makes freckles.

There is no way of removing at once freckles or tan. They usually
disappear in the winter. No powders nor any other kind of medicine
should be taken to make the skin white and smooth. Such medicines may
contain poison and are likely in time to hurt the body. The skin may
usually be kept soft and smooth by washing well with soft water and
good soap. If it becomes harsh or cracked, a little glycerine rubbed
on after each washing may help it.

=The Nails and their Care.=--The nails are hardened parts of the
epidermis. They are intended to prevent the ends of the fingers from
being hurt and to give a neat appearance to the hand.

The ends of the nails should never be chewed or torn off, as this
makes the fingers blunt and the flesh sore. They should be filed or
cut neatly with the scissors so that they do not stick out beyond the
ends of the fingers.

[Illustration: FIG. 46.--Photograph of hands showing at the right how
the nails should appear, and at