nough to allow the feet to
rest easily upon the floor, but not too low. The desk should be of such
a height that, in writing, one shoulder will not be raised above the
other. If a young person bends the body forward, he will, after a time,
become round-shouldered and his chest will become so flattened that the
lungs cannot be well expanded.

[Illustration: DESK TOO HIGH.]

~6.~ Standing on one foot, sitting bent forward when reading or at work,
sleeping with the head raised high upon a thick pillow or bolster, are
ways in which young persons often grow out of shape.

[Illustration: SEAT TOO HIGH.]

~7. The Clothing.~--Wearing the clothing tight about the waist often
produces serious deformities of the bones of the trunk, and makes the
chest so small that the lungs have not room to act properly. Tight or
high-heeled shoes also often deform and injure the feet and make the
gait stiff and awkward.

~8. Broken Bones.~--By rough play or by accident the bones may be broken
in two just as you might break a stick. If the broken parts are placed
right, Nature will cement them together and make the bone strong again;
but sometimes the bones do not unite, and sometimes they grow together
out of proper shape, so that permanent injury is done.

~9. Sprains.~--In a similar manner the ligaments which hold the bones
together, in a joint, are sometimes torn or over-stretched. Such an
accident is called a sprain. A sprain is a very painful accident, and a
joint injured in this way needs to rest quite a long time so that the
torn ligaments may grow together.

~10. Bones out of Joint.~--Sometimes the ligaments are torn so badly
that the ends of the bones are displaced, and then we say they are put
out of joint. This is a very bad accident indeed, but it often happens
to boys while wrestling or playing at other rough games.

~11.~ Children sometimes have a trick of pulling the fingers to cause
the knuckles to "crack." This is a very foolish and harmful practice. It
weakens the joints and causes them to grow large and unsightly.

~12.~ When a man uses alcohol and tobacco, their effects upon the bones
are not so apparent as are the effects upon the blood, the nerves, and
other organs; but when the poisonous drugs are used by a growing boy,
their damaging influence is very plainly seen. A boy who smokes cigars
or cigarettes, or who uses strong alcoholic liquors, is likely to be so
stunted that even his bones will not grow of a proper