oice of some value to its possessor, should have a good, practical
knowledge of the mechanism of the voice. Good voices are often injured by
injudicious management on the part of some incompetent instructor. It is
always prudent to cease speaking or singing in public the moment there is
any hoarseness or sore throat.

The voice should not be exercised just after a full meal, for a full
stomach interferes with the free play of the diaphragm. A sip of water
taken at convenient intervals, and held in the mouth for a moment or two,
will relieve the dryness of the throat during the use of the voice.

356. Effect of Alcohol upon the Throat and Voice. Alcoholic beverages
seriously injure the throat, and consequently the voice, by causing a
chronic inflammation of the membrane lining the larynx and the vocal
cords. The color is changed from the healthful pink to red, and the
natural smooth surface becomes roughened and swollen, and secretes a tough
phlegm.

The vocal cords usually suffer from this condition. They are thickened,
roughened, and enfeebled, the delicate vibration of the cords is impaired,
the clearness and purity of the vocal tones are gone, and instead the
voice has become rough and husky. So well known is this result that
vocalists, whose fortune is the purity and compass of their tones, are
scrupulously careful not to impair these fine qualities by convivial
indulgences.

357. Effect of Tobacco upon the Throat and Voice. The effect of
tobacco is often specially serious upon the throat, producing a disease
well known to physicians as "the smoker's sore throat." Still further, it
produces inflammation of the larynx, and thus entails disorders of the
vocal cords, involving rough voice and harsh tones. For this reason
vocalists rarely allow themselves to come under the narcotic influence of
tobacco smoke. It is stated that habitual smokers rarely have a normal
condition of the throat.

Additional Experiments.

Experiment 189. _To illustrate the importance of the resonating
cavity of the nose in articulation_. Pinch the nostrils, and try to
pronounce slowly the words "Lincoln," "something," or any other words
which require the sound of _m_, _ln_, or _ng_.

[Illustration: Fig. 154.]

Experiment 190. _To illustrate the passage of air through the
glottis._ Take two strips of India rubber, and stretch them over the
open end of a boy's "bean-blower," or any kind of a tube. Tie them
tigh