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LECTURE Vlli; 



ON VOICiE AND LANGUAGE ; VOCAl, IMITATION ; AND VENTRILOQUISM. 



Language, in the fullest scope of the term, is of two kinds ; natural 

 and articulate or artificial. The first belongs to most animals ; the last is 

 peculiar to man : it is his great and exclusive prerogative. This also is of 

 two divisions ; oral or vocal, which constitutes speech ; and literal or legi- 

 ble, which constitutes writing. The first of these divisions shall form our 

 subject for the present study ; the second we will examine in a subsequent 

 lecture. 



At the root of the tongue lies a minute semi-lunar shaped bone, which 

 from its resemblance to the Greek letter t/, or upsilon, is called the hyoid 

 or u like bone ; and immediately from this bone arises a long cartilaginous 

 tube, which extends to the lungs, and conveys the air backward and for- 

 ward in the process of respiration.* This tube is denominated the trachea 

 or windpipe ; and the upper part of it, or that immediately connected with 

 the hyoid-bone, the larynx : and it is this upper part or larynx alone that 

 constitutes the seat of the voice. 



The tube of the larynx, as short as it is, is formed of five distinct car- 

 tilages ; the largest, and apparently, though not really, lowermost of which, 

 produces that acute projection or knot in the anterior part of the neck, and 

 especially in the neck of males, of which every one must be sensible. This 

 is not a complete ring, but is open behind ; the open space being filled 

 up, in order to make a complete ring, with two other cartilages of a smaller 

 size and power ; and which together form the glottis, as it is called, bv 

 aperture out of the mouth into the laryni. The fourth cartilage lies im- 

 mediately over this aperture, and closes it in the act of swallowing, so as 

 to direct the food to the esophagus, another opening immediately behind 

 it, which leads to the stomach. These four cartilages are supported by a 

 fifth, which constitutes their basis ; is narrow before, and broad behind, 

 and has some resemblance to a seal-ring. The larynx is contracted and 

 dilated in a variety of ways by the antagonist power of different muscles, 

 and the elasticity of its cartilaginous coats ; and is covered internally with 

 a very sensible, vascular, and mucous membrane, which is a continuation 

 of the membrane of the mouth. 



The organ of the voice, then, is the larynx, its muscles, and other 

 appendatres ; and the voice itself is the sound of the air propelled through 

 and striking against the sides of its glottis, or opening into the mouth. 

 The shrillness or roughness of the voice depends on the internal diameter 

 of the glottis, its elasticity, mobility, and lubricity, and the force with which 

 the air is protruded. Speech is the modification of the voice into distinct 

 articulations, in the^ cavity of the glottis itself, or in that of the mouth, or 

 of the nostrils. 



Those animals only that possess lungs, possess a larynx, and hence none 

 but the three first classes in the Linnean system, consisting of mammals, 

 birds, and amphibials. Even among these, however, some genera or spe- 

 cies are entirely dumb, as the myrmecophaga, or ant-eater, the mams or 



* Stua. of Med. i. p. 457, edit. i. 



