ity of which (known as the thoracic cavity) is
occupied mainly by the lungs and heart. It is bounded by the spinal
column, the ribs with their cartilages, the breastbone, and below by
the diaphragm. It is generally spoken of as "the chest." It has been
compared to a completely shut, conical box, the small end of which Is
turned upward, the back of the box being formed by the spinal column,
the front by the breastbone and the sides by the ribs.

The ribs are twenty-four in number, twelve on each side, and emerge
from each side of the spinal column. The upper seven pair are known as
"true ribs," being fastened to the breastbone direct, while the lower
five pairs are called (false ribs) or "floating ribs," because they
are not so fastened, the upper two of them being fastened by cartilage
to the other ribs, the remainder having no cartilages, their forward
ends being free.

The ribs are moved in respiration by two superficial muscular layers,
known as the intercostal muscles. The diaphragm, the muscular
partition before alluded to, separates the chest box from the
abdominal cavity.

In the act of inhalation the muscles expand the lungs so that a vacuum
is created and the air rushes in in accordance with the well known law
of physics. Everything depends upon the muscles concerned in the
process of respiration, which we may as, for convenience, term the
"respiratory muscles." Without the aid of these muscles the lungs
cannot expand, and upon the proper use and control of these muscles
the Science of Breath largely depends. The proper control of these
muscles will result in the ability to attain the maximum degree of
lung expansion, and the greatest amount of the life giving properties
of the air into the system.

The Yogis classify Respiration into four general methods, viz:

(1) High Breathing.

(2) Mid Breathing.

(3) Low Breathing.

(4) Yogi Complete Breathing.

We will give a general idea of the first three methods, and a more
extended treatment of the fourth method, upon which the Yogi Science
of Breath is largely based.

(1) HIGH BREATHING.

This form of breathing is known to the Western world as Clavicular
Breathing, or Collarbone Breathing. One breathing in this way elevates
the ribs and raises the collarbone and shoulders, at the same time
drawing in the abdomen and pushing its contents up against the
diaphragm, which in turn is raised.

The upper part of the chest and lungs, w