Your tongue and lips, like the rest of your skin, are always touching
and feeling things for you and sending messages to the brain. They say
whether your milk is hot or cold, and whether the food you eat is soft
enough and quite right in other ways. Your tongue is a very busy
little "waiter": he passes the food about in your mouth for the teeth
to chew, and he rolls it about at a great rate. But he does more than
this; he tells you something about how it tastes--not everything, as
you may think, but only whether it is _bitter_, _sweet_, _sour_, or
_salty_. Queer as it may seem, your nose tells you the other "tastes,"
which are really smells. It is your nose that says whether you have a
strawberry or a piece of onion in your mouth, whether it is coffee or
cocoa that you are drinking.

Of what other use is your nose?--for only a little patch in the upper
part is for smelling and tasting. The greater part of the nose is to
breathe through. You see, your nose warms and moistens the outside air
that you take in, so that, by the time it reaches your throat, it is
as warm as your body and does not hurt your throat. Your nose also
strains, or filters, out of the air the dust, lint, and germs that may
be floating in it.

You should always keep your lips closed and breathe through your nose.
Whenever you cannot breathe through your nose, there is something the
matter. It may be that your nose is swollen shut with a "cold"; but
that will last only a few days. If, however, your nose often feels
"stuffed up," there is probably something in it or behind it, that
ought to be taken away. A throat doctor can easily cure you; and, when
he has, you'll be surprised how much better you feel and how much
faster you grow.