more light or noise into the room, this is of no importance whatever
compared with abundance of fresh air. If you have played long enough
out of doors in the daytime and have eaten a good supper and not
stayed up too late, you will sleep soundly without being bothered at
all by either lights or noises coming in through 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