Great wisdom is exhibited in the construction of the human lungs. In the
arrangement of the air cells, the greatest possible amount of surface is
presented in order that the air may freely enter the blood. The lungs
are largely made up of blood vessels, bronchial tubes, and air cells.
When a person breathes, the oxygen, entering the lungs through the
trachea and the bronchial tubes, penetrates the thin walls of these
cells and passes at once into the blood. When the blood enters the lungs
it is dark in color, but when it leaves the lungs it is of a light
vermilion hue. The oxygen which has been taken into the lungs has
wrought this change. So wonderful is this element of nature that some
have called it life. If there is an elixir of life in the material world
surely it is oxygen, for it has to do minutely and intimately with every
power of the human body. The more a person breathes this oxygen as it is
mixed in the common air, the more life and power he possesses.
It is essential to perfect health that every avenue to the lungs should
be kept open and free, and that the air cells should be kept clear, for
if the walls of the cells thicken, oxygen cannot penetrate them. If
these cells are not properly filled during respiration, the walls
thicken, and substances collect in the cells. If any trouble occurs in
the air cells, except for traumatic reasons, it will first be found in
the apexes of the lungs. In the production of tone, whether on a low,
high, or medium pitch, the vocal cords are drawn so closely together
that the air cannot immediately escape from the lungs; therefore, unable
to get out readily, it is pressed up into the apexes of the lungs by the
expiratory muscles, filling the air cells to the utmost, thus keeping
them clear and their walls thin and healthy. In correct singing or
speaking, the apexes of the lungs are filled with air. Tubercule seeks
devitalized tissue for its development. Therefore tuberculosis usually
begins in the apexes of the lungs because they are not kept clear and
healthy through proper respiration and vocal exercise. Voice was given
to man to make him strong and expressive, to give him life and power.