be
undertaken.

CHAPTER II

THE FALLACY OF THE DOCTRINE OF BREATH-CONTROL

When Dr. Mandl advanced the statement that the laryngeal muscles are too
weak to withstand the pressure of a powerful expiratory blast, the
theory of the vocal action therein embodied met with immediate
acceptance. This idea is so plausible that it appeals to the thoughtful
investigator as self-evident, and seems to call for no proof. The
doctrine of breath-control was at once adopted, by the most influential
vocal scientists, as the basic principle of tone-production.

Curiously, neither Dr. Mandl, nor any other advocate of breath-control,
seems to have read an article by Sir Charles Bell dealing with this same
action, the closing of the glottis against a powerful exhalation. This
paper, "On the Organs of the Human Voice," was read before a meeting of
the London Philosophical Society on February 2, 1832.

Dr. Bell dispels all the mystery concerning the closure of the glottis,
and the holding of the breath against a powerful contraction of the
expiratory muscles. He points out that this action occurs in accordance
with the law of the distribution of pressure in a fluid body, commonly
known as Pascal's law of fluid pressures.

Pascal's law is stated as follows:--"Pressure exerted anywhere upon a
mass of fluid is transmitted undiminished in all directions, and acts
with equal force on all equal surfaces, and in a direction at right
angles to those surfaces." (Atkinson's _Ganot's Physics_, 4th ed., New
York, 1869.)

The hydraulic press furnishes the familiar illustration of this law. Two
vertical cylinders, one many times larger than the other, are connected
by a pipe. The cylinders are fitted with pistons. Both the cylinders,
and the pipe connecting them, are filled with water, oil, air, or any
other fluid; the fluid can pass freely from one cylinder to the other,
through the connecting pipe. Suppose a horizontal section of the smaller
cylinder to measure one square inch, that of the larger to be one
hundred square inches. A weight of one pound on the smaller piston will
balance a weight of one hundred pounds on the larger. If a downward
pressure of one pound be exerted on the smaller piston, the larger
piston will exert an upward pressure of one hundred pounds. Conversely,
a downward pressure of one hundred pounds, exerted on the larger piston,
will effect an upward pressure of only one pound on the smaller piston.

A type of the