keeping the midriff down and the chest walls
extended, and count four mentally, at the rate of sixty per minute. Then
let the breath go _suddenly_. The result of this will be a flying up of
the midriff, and a falling down of the ribs; in other words, there will
be a collapse of the lower part of the body. This collapse may not at
first be very distinct, as the extension has probably been insufficient;
but both will become more and more perfect as the result of continued
practice.

Let it be clearly understood: The _in_spiration is to be slow and deep,
the _ex_piration sudden and complete. In _in_spiration the abdomen and
the lower part of the chest expand, and in _ex_piration they collapse.

The time of holding the breath is not, at the outset, to exceed four
seconds, and the student must never, on any account, fatigue himself
with these exercises; they may, however, be frequently repeated at
intervals. It will be found by occasional trials upon the spirometer
that the breathing capacity increases with these exercises. The process
of abdominal respiration becomes easy and no longer requires constant
watchfulness, and the student will soon be able to carry it on, not only
lying down, but while he is standing or walking, though not at once with
the same ease. He must now, for a time, be careful to see that he has
the same physical sensations in breathing which he noticed while making
his first experiment when lying down; and he must exercise special care
when running, going upstairs, &c., and, of course, in speaking or
singing.

The criterion of correct inspiration is, as I have said before, an
increase of size of the abdomen and of the lower part of the chest.
Whoever draws in the abdomen and raises the upper part of the chest in
the act of filling his lungs does wrong.

Meanwhile, in continuing the breathing exercises, the time of holding
the breath may be increased at the rate of two seconds per week; so that
the student who, during the first fortnight, limited himself to four
seconds will, at the end of six weeks, hold his breath during twelve
seconds. I have, in some instances, with students of mine, gone as far
as twenty seconds; but I desire very earnestly to warn my readers to be
cautious and not to go to extremes. Nothing will be gained, but infinite
harm may ensue by over-doing these lung gymnastics, and persons at all
inclined to bleeding from the lungs should not undertake the exercises
at all, except wit