a schoolroom enough flax can be raised to make a
half dozen collars. Garments to be worn in warm weather are sometimes
made of linen.

=Silk.=--Silk is used in making neckties, gloves, ribbons, and
dresses. Silk cloth is woven from the cocoons made by silkworms. A
silkworm is about as big as your largest finger. It grows to this
size from the egg in one month. In three or four days it spins a shell
of silk thread completely surrounding itself. This shell is called a
_cocoon_. Within this it changes to a moth.

[Illustration: FIG. 51.--Photograph of silkworms changing mulberry
leaves into silk.]

[Illustration: FIG. 52.--These fibers from the lint about the seed of
cotton are woven into cotton cloth.]

When the cocoons are to be used for silk, the worm is killed by heat
as soon as it has woven its home so that it may not change to a moth
and eat off some of the silk in getting out. Many thousand worms are
needed to get enough silk for a dress. The worms are raised largely in
China, Japan, Italy, and France.

=Cotton.=--All calico, muslin, and most cheap clothing are made from
cotton thread. This is made from the cotton fibers surrounding the
seeds of the cotton plant (Fig. 52). The cotton used in this country
is raised in the Southern states.

Cotton clothing is stronger and wears much longer than silk or wool,
but it does not look so well and is not nearly so warm.

=The Use of Wraps and Overcoats.=--_Outer wraps and overcoats should
never be worn in a warm room or while working hard._ They cause much
sweat to form on the body, and as soon as one goes out of doors the
sweat begins to pass off. This makes the body feel cold and in some
cases leads to a long sickness.

When riding in cold weather, extra wraps should be worn. Scarfs and
furs should not be worn about the throat except in extreme cold
weather. Bundling up the neck and chin is likely to cause sore throat.

=Danger from Wet Clothing.=--Many children have caught severe colds
leading to serious sickness by wearing wet or damp clothing. Wet
clothing causes the heat to pass off from the body quickly, so that it
is chilled before we know it. This may be shown by wrapping two bottles
of warm water in cloths. Wet one cloth and let the other remain dry. In
twenty minutes the bottle with the wet cloth will be cool, but the other
one will still be warm. _If your wet clothing cannot be changed at once,
keep exercising or throw a heavy coat about you._

=Unt