same way, when it becomes wet with sweat. The sweat comes from the
blood under the skin; so that, as we saw before, by letting this
moisture pass through, the skin acts as a sieve to let out the waste
from the blood.

Then, too, the skin covers and protects all the other parts. It is
thin where it needs to be thin, so as not to interfere with quick
movements, as on the eyelids and the lips; and thick where it needs to
be thick, to stand wear and tear, as on the soles of the feet and the
palms of the hands. I remember once taking a sliver of shingle out of
the back of a little boy who had been sliding down a roof. I had to
sharpen my knife and press and push and at last get a pair of scissors
to cut out the sliver. It was just like cutting tough leather. But
even if we do sometimes get cuts and burns and bruises, yet our skin
coat protects us far more than we really think. It keeps out all sorts
of poisons and the germs of blood-poisoning and such diseases. These
enemies can attack us only through a scratch or cut in the skin, for
that is the only way they can get into the blood. The skin is better
than any manufactured coat, too, because, if it is torn or scratched,
it can mend itself.

[Illustration: READING BY TOUCH INSTEAD OF SIGHT

These boys are blind; their books are printed with raised
letters, which they read by feeling of them.]

Does your skin ever talk to you? No, of course not; yet it tells you
ever so many things. Shut your eyes and pick up a pencil. As you touch
it, your skin tells you that it is round and smooth, and pointed at
one end. You can feel the soft rubber on the other end, too. Is it