3. We should not keep our rooms too warm, and should avoid wearing too
much clothing.

4. Alcohol, tobacco, and other stimulants and narcotics injure the skin.




CHAPTER XVII.

THE KIDNEYS AND THEIR WORK.


~1. The Kidneys.~--The kidneys are among the most important organs of
the body. They are in the cavity of the abdomen, near the back-bone, up
under the lower border of the ribs. Perhaps you have seen the kidneys of
a sheep or a hog. If you have, you know very nearly how the kidneys of
our own bodies appear.

[Illustration: KIDNEY.]

~2. The Work of the Kidneys.~--The work of the kidneys is to separate
from the blood certain very poisonous substances, which would soon cause
our death if they were not removed. It is very important to keep these
useful organs in good health, because a person is certain to die very
soon when the kidneys are in any way seriously injured.

~3. How to Keep the Kidneys Healthy.~--One way of keeping the kidneys in
good health is to drink plenty of pure water, and to avoid eating too
much meat and rich food. Pepper, mustard, and other hot sauces are very