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seventh above the prime, with seven times as many vibrations.

The seventh upper partial is three octaves above the prime, with eight times the number of vibrations.

Many other partials occur in some compound tones, but always in the same relative position.

"Simple Tones have a very soft, pleasant sound, free from all roughness, but wanting in power and dull at low pitches."

"Musical Tones, which are accompanied by a moderately loud series of the lower upper partial tones, up to about the sixth partial, are more harmonious and musical. Compared with simple tones they are rich and splendid, while they are at the same time perfectly sweet and soft if the higher upper partials are absent."

"If only the uneven partials are present the quality of tone is hollow, and when a large number of such upper partials are present, nasal. When the prime tone predominates the quality of the tone is rich or full; but when the prime tone is not sufficiently superior in strength to the upper partials, the quality of the tone is poor or empty."

"When partial tones higher than the sixth or seventh are very distinct, the quality of the tone is cutting and rough. The degree of harshness may be very different. When their force is inconsiderable the higher upper partials do not essentially detract from the musical applicability of the compound tones; on the contrary they are useful in giving character and expression to the music."*

It is found that one sounding body has the power of putting another body in vibration without being in contact with it. When the strings of two violins are in perfect unison, if the string of one is bowed the string of the other will be set in vibration.

*Sensation of Tone: Helmholtz.

"Tuning-forks are the most difficult to set in sympathetic vibration. To effect this they must be fastened on soundingboxes which have been exactly tuned to their tone. If we have two such forks of exactly the same pitch, and excite one by a violin bow the other will begin to vibrate in sympathy, even if placed at the farther end of the room, and it will continue to sound when the first is damped. The astonishing nature of such a case of sympathetic vibration will appear, if we merely compare the heavy and powerful mass of steel set in motion with the light, yielding mass of air, which produces effect by such small motive power that it could not stir the lightest spring which was not in tune with the fork. With such forks the time required to set them in full swing by sympathetic action is also of sensible duration, and the slightest disagreement in pitch is sufficient to produce a sensible diminution in the sympathetic effect. By sticking a piece of wax to one prong of the second fork, sufficient to make it vibrate once in a second less than the first, a difference of pitch scarcely sensible to the finest ear, the sympathetic vibration will be wholly destroyed."*

Thus sympathetically the entire vocal passage, chest, and head reinforce the tones of the vocal bands.

The Physical Value of Vowels. - One vowel sound is distinguished from another, though both have the same pitch and intensity. This fact was long a question of inquiry. Sir C. Wheatstone first stated the true theory, which was afterwards subjected to exhaustive study by Helmholtz. "The vibrations. of the vocal bands associate with the resonant cavity of the mouth, which can so alter its shape as to resound at will either the fundamental tones of the vocal cords or any of their overtones. With the aid of the mouth, therefore, we can mix together the fundamental tone and the overtones of the voice in different combinations. Helmholtz was able to imitate

*Sensation of Tone.

these tones by tuning-forks, and by combining them appro priately together to produce the sounds of all the vowels."*

We have this important proof that the musical and consequently the carrying quality of speech depends upon the vowel elements.

* On Sound.

CHAPTER III.

RESPIRATION.

THAT part of respiration carried on by the lungs is naturally related to vocal effort, and its physiology and function should be understood.

The lungs are two large sacks lying in the thoracic cavity, one on each side of the heart. They consist of bronchial tubes, and their terminal air-cells, numerous blood-vessels, nerves, and lymphatics. The connective tissue binding these tubes and cells together is composed of highly elastic fibres. "Each lung is covered, except at one point, by an elastic serous membrane called the pleura, which adheres tightly to it. At the root of the lungs, the pleura turns back and lines the inside of the chest cavity."* This provision lessens friction between the chest walls and the lungs during the movements of respiration.

The ramification of these bronchial tubes is tree-like.

The trachia or windpipe, felt in the front part of the neck, "consists fundamentally of a fibrous tube in which cartilages are embedded to keep it from collapsing." These cartilaginous rings are horseshoe in shape, the round part being in front. The back part of the windpipe, against which the gullet lies, is not hard like the front, "and the absence there of these cartilages no doubt facilitates swallowing."

The lower end of the windpipe branches off into two greater bronchi, which continue to separate into the lesser

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*Quotations in this and the succeeding chapter, marked with an asterisk (*) are from the work of Dr. Martin on The Human Body," which we have accepted as authority on the physiology and function of the respiratory and vocal apparatus.

bronchi. At the upper part of the windpipe is situated the larynx, or voice-box; above this we have the pharynx and mouth cavities connecting with the outer air.

The breathing movements consist (a) of inspirations, during which the chest cavity is enlarged and fresh or oxygenated air enters the lungs, alternating with (b) expirations, in which the cavity is diminished and the air, burdened with carbon dioxide, is expelled from the lungs.

The thorax, or chest, is supported by the framework afforded by the dorsal vertebræ, breastbone, and ribs. "Between and over these lie the muscles, and the whole is covered air-tight by the skin externally."

The Enlargement of the Thorax for Inspiration. — 1. The Diaphragm is a strong, sheet-like muscle, arching up dome-like, separating between the chest and the abdominal cavities. Its muscular fibres radiate from the dome downwards and outwards, and are attached to the breastbone, the lower ribs, and the vertebral column. By contraction the diaphragm sinks to a horizontal position, thus greatly increasing the size of the thorax vertically.

2. The ribs slope downwards from the vertebral column to the breastbone. "The scalene muscles, three on each side, arise from the cervical vertebræ and are inserted into the upper ribs. The external intercostal lie between the ribs and extend from the vertebral column to the costal cartilages; the fibres slope downward and forwards."

“During inspiration the scalenes contract and fix the upper ribs firmly; then the external intercostal shortens and each raises the rib below it." Thus the ribs are elevated, the breastbone shoved out from the spine, and the capacity of the thorax enlarged from front back. Other muscles are employed, but chiefly in offering points of resistance to those already described. These are the principal ways of enlarging the chest, and require considerable muscular effort.

Now, when the chest is enlarged, the space between the

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