472 MUSCULAR MOTION. 



racterizes that instrument ; and on the other hand, if the tube be ex- 

 panded at its middle portion, the quality of the sound is raucous and 

 dull. It is probable, therefore, that we must reckon, amongst the ele- 

 ments of the varying character of the timbre or stamp of the voice, the 

 different conditions of the vocal tube, as to length, width, and form; 

 and that we must likewise include the position and shape of the tongue, 

 of the velum palati, mouth and nose, the presence or want of teeth, &c., 

 all which modify the voice considerably. The first modification takes 

 place, probably, in the ventricles of the larynx, in which the voice 

 acquires more rotundity and expansion. It was remarked by Dr. Isaac 

 Parrish, 1 that a peculiar change was induced in two cases by the excision 

 of the tonsils. The voice was rendered shrill and whistling. 



By the generality of physiologists, it is conceived, that the voice 

 enters the diiferent nasal fossae, and, by resounding in them, a timbre 

 or character is given to it, which it would not otherwise possess. Ac- 

 cording to this view, when it is prevented from passing through the 

 nose, from any cause, it acquires the nasal twang ; or, by a singular in- 

 accuracy of language, we are said "to talk through the nose." M. Ma- 

 gendie, 2 however, considers, that whenever the voice passes through the 

 nasal fossae, it becomes disagreeable and nasal. The sample experiment 

 of holding the nose exhibits, that, in the enunciation of the true vocal 

 sounds, unmodified by the action of the organs of articulation, the 

 timbre or quality is materially altered; and we shall see, hereafter, that 

 there are certain letters, that do not admit of enunciation, unless the 

 nasal fossae be pervious the m, the n, and ng, for example. It would 

 seem that, under ordinary circumstances, the sound, after it is produced 

 in the larynx, flows out by both channels ; and that, if we either shut 

 off the passage through the nose altogether, or attempt to pass it more 

 than usually through the nasal fossae, the voice becomes nasal. The 

 fine, sharp voice prior to puberty is especially owing to the narrowness 

 of the glottis, the shortness of the ligaments, and, according to M. Mal- 

 gaigne, 3 the want of developement of the nasal cavities. At puberty, 

 the size of the opening of the larynx is doubled; the ligaments enlarge, 

 and the size of the passages of the nose is augmented. The timbre now 

 becomes raucous, dull, and coarse; and for a time the harmony of the 

 voice is lost. M. Bennati, 4 himself an excellent theoretical and prac- 

 tical musician, whose voice marks three octaves, advises, that the voice 

 should not be much exerted during this revolution. He has known 

 perseverance in singing at this time in several instances completely 

 destroy the voice. 



Not only does the voice, when produced in the larynx, pass out by 

 the vocal tube, but it resounds along the tracheal and bronchial tubes, 

 giving rise to the resonance or thrill, audible in certain parts of the 

 chest, more especially, when the ear or the stethoscope is placed over 

 them ; and, when cavities exist in the lungs, in the consumptive, if the 



1 Quarterly Summary of the Transactions of the College of Physicians of Philadelphia, 

 Nov. and Dec., 1841, and Jan., 1842. 2 Precis Elementaire, i. 254. 



3 Archives Generates de Medecine, pp. 201 and 214, Fevrier, 1831. 



4 Recherches sur le Mecanisme de la Voix Humaine, Paris, 1832. 



