Page:Popular Science Monthly Volume 9.djvu/543

Rh curious change takes place suddenly in the configuration of the glottis: it appears to be absolutely shut below and open above. In proportion as the orifice is narrowed, the sound grows higher. The singer recognizes the registers by the ear from the timbre, the physiologist by the eye; for the latter, one of the registers consists of the series of sounds produced by the glottis when open along its entire length, the other register represents the series of sounds given forth by the glottis open through only a limited portion of its orifice.

The ordinary limits of the voice include about two octaves of the musical scale; by practice one can easily attain $2 1⁄2$ octaves, but a compass of three octaves, and especially of $3 1⁄2$ octaves, is very exceptional. Hence, at the beginning of the present century, Catalani was regarded as a sort of prodigy. In classing voices according to pitch we recognize three kinds of voice in men, viz., bass, barytone, and tenor, and three in women, contralto, mezzo-soprano, and soprano. Bass voices rarely fall below 173 vibrations, and soprano seldom exceed 2,069 vibrations per second. Still there have been deep voices which produced the note corresponding to 87 vibrations, and acute voices which attained as many as 2,784. The most famous cantatrices of our day are instances of this. The different types of voice are characterized no less by their timbre than by their range. Voices present so many varieties, they are so personal, that thorough classification is almost impossible. Endless shades of difference are produced by the degree of intensity of the harmonics: if the intensity is great, the voice is brilliant, mordant; if feeble, the voice is soft, sombre. In the larynx itself, and in the trachea, there occurs a resonance, the effects of which have not yet been determined. In bass voices they are very noteworthy. The famous Lablache would have been an excellent subject for experiments by physiologists.

Having ascertained all the functions of the vocal apparatus, and accounted for the origin of the sounds of speech and singing, we may well be proud of the advance made by science, yet we cannot but be chagrined to think that it is not in our power to determine to what peculiarities of organic conformation the different kinds of voice are to be attributed. All that we can affirm with certainty is, that the sound produced is acute in proportion to the shortness of the vocal cords. One might be inclined to believe that the larynx is more voluminous in bassi than in tenori, in contralti than in soprani; but this is not universally the case. We cannot determine either the compass or the quality of a voice from seeing the instrument. The elasticity, suppleness, and contractility of the tissues, must have an immense