, on each side, a pair of nerves. The lower broad part of the
spine, (see _p_, Fig. 1, p. 70, and Fig. 7, p. 77,) is called the
_sacrum_; in this, are eight holes, through which the lower pairs of
nerves pass off.

The nerves of the head and lungs run directly from the brain; those of
all other parts of the body proceed from the spine, passing out in the
manner already mentioned.

The nerves which thus proceed from the spine, branch out, like the limbs
and twigs of a tree, till they extend over the whole body; and, so
minutely are they divided and arranged, that a point, destitute of a
nerve, cannot be found on the skin.

Some idea of the ramifications of the nerves, may be obtained by
reference to the following engraving, (Fig. 8.) In this, A, A,
represents the _cerebrum_, or great brain; B, B, the _cerebellum_, or
little brain; (see also _a_, _b_, in Fig. 6;) C, C, represents the union
of the fibres of the cerebrum; D, D, the union of the two sides of the
cerebellum; E, E, E, the spinal marrow, which passes through the centre
of the spine, (as seen at _c_, _d_, _e_, in Fig. 6;) 1, 2, 3, 4, 5, 6,
branches of the nerves going to different parts of the body. As the
nerves are the organs of sensation, all _pain_ is an affection of some
portion of the nerves. The health of the nerves depends very greatly on
the exercise of the muscles, with which they are so intimately
connected. This shows the reason why the _headache_, _tic douloureux_,
diseases of the _spine_, and other nervous affections, are so common
among American women. Their inactive habits, engender a debility of the
nervous system, and these diseases follow, as the consequence.

[Illustration: Fig. 8.]

It can be seen, by a reference to the side view, represented on page
77, (Fig. 6,) that the spine is naturally curved back and forward.
When, from want of exercise, its bones are softened, and the muscles
weakened, the spine acquires an improper curve, and the person becomes
what is called _crooked_, having the neck projected forward, and, in
some cases, having the back convex, where it should be concave. Probably
one half of the American women have the head thus projecting forward,
instead of carrying it in the natural, erect position, which is both
graceful and dignified.

The curvature of the spine, spoken of in this work as so common, and as
the cause of so many diseases among American women, is what is
denominated the _lateral curvature_, and is much