the windows. And no
matter how cold or how light it is, don't put your head under the
bedclothes. Why?

It is best for you to close your mouth while you are going to sleep,
and breathe through your nose, so that the air will be properly
purified and warmed before it reaches your lungs. If you can't do
this, your mother can perhaps give you something to wash out your
nose, so that you can breathe freely. If that does not help, you had
better see a doctor, and he will find some way to clear your head so
that you can use your nose comfortably.

Suppose you take a pencil and paper and write down all you did
yesterday. Wasn't it enough to make you tired and sleepy and want a
chance to rest? Even while you sleep, your heart keeps beating, and
you don't stop breathing, of course. But your muscles are quiet, and
your food tube rests. Your brain rests, too,--better in sleep than at
any other time,--so that when morning comes you are as "lively as a
cricket" and quite ready for the new day.

Yet even in sleep your brain does not stop working entirely, but goes
on receiving messages from the stomach and the skin and the memory,
and mixing them up together in the strangest fashion, so that you
_dream_, as you say. You ought not to dream very much if you are
perfectly well; but as long as your dreams are pleasant or amusing,
you need not pay any attention to them. But if you have had bad
dreams, or you dream so hard all night long that you don't feel rested
in the morning, then you had better speak to your mother about it, and
let her see what is the matter with your digestion or your nerves, or
take you to a doctor. Bad dreams are always a sign of ill health and
are a very disagreeable thing, from which there is no need that you
should suffer any more than from headache or indigestion or colic.
Dreams, of course, do not mean or foretell anything whatever, except
simply how bad, or good, the state of your digestion and your nerves
is.

Now, how much time should you spend in bed? Well, I think at your age
nearly half the time. Ten or eleven hours of sleep make you ready for
all the hours of work and play, and you don't become cross and tired
half so easily if you have plenty of sleep. Though you are lying so
quietly, you are not by any means wasting your time, for you probably
are growing faster when you are asleep than when awake. Babies, who
are growing very fast, you know, sleep nearly all the time.

So after you have opene