468 OF THE VOICE AND SPEECH. 



combination does not really produce anything like it. For producing this 

 sound, the point of the tongue is applied to the back of the incisors, or to the 

 front of the palate, as in sounding t ;* but, whilst there is complete contact of 

 the tip, the air is allowed to pass out around it. n. In the second class of 

 continuous consonants, including the letters m, n, /, and r, the nostrils are not 

 closed; and the air thus undergoes very little compression, even though the 

 passage of air through the oral cavity is almost or completely checked. In 

 pronouncing m and n, the breath passes through the nose alone; and the dif- 

 ference of the sound of these two letters, must be due to the variation in the 

 form of the cavity of the mouth, which acts by resonance. The letter m is a 

 labial, like b ; and the only difference between the two is, that in the former 

 the nasal passage is open, whilst the mouth remains closed; whilst in the 

 latter, the nose is entirely closed, and the sound is formed at the moment of 

 opening the mouth. The same correspondence exists between n and t, or n 

 and g (the particular part of the tongue approximated to the palate not being 

 of much consequence in the pronunciation of n} ; and hence it is that the 

 transition from n to t, or from n to g, is so easy, that the combinations nt and 

 ng are found abundantly in most languages. The sound of / is produced, by 

 bringing the tip of the tongue into contact with the palate, and allowing the 

 air to escape around it, at the same time that a vocal tone is generated in the 

 larynx ; it differs, therefore, from th in the position at which the obstruction 

 is interposed, as well as in the slight degree of the compression of the air 

 which it involves. The sound of the letter r depends on an absolute vibration 

 of the point of the tongue, in a narrow current of air forced between the tongue 

 itself and the palate, m. The sounds of the third class are scarcely to be 

 termed consonants, since they are merely aspirations, caused by an increased 

 force of breath. These are h, and the cAt of most foreign languages (the 

 Greek #). The first is a simple aspiration ; the second, an aspiration modified 

 by the elevation of the tongue, causing a slight obstruction to the passage of 

 air, and an increased resonance in the back of the mouth. This sound would 

 become either g or k, if the tongue, whilst it is being produced, were carried 

 up to touch the palate.J 



617. These distinctions come to be of much importance, when we apply 

 ourselves to the treatment of defects of articulation. Great as is the number 

 of muscles employed in the production of definite vocal sounds, the number 

 is much greater for those of articulate language ; and the varieties of combina- 

 tion, which we are continually forming unconsciously to ourselves, would not 

 be suspected, without a minute analysis of the separate actions. Thus, in ut- 

 tering the explosive sounds, we check the passage of air through the posterior 

 narcs, in the very act of articulating the letter; and yet, this important move- 

 ment commonly passes unobserved. We must regard the power of forming 

 the several articulate sounds which have been adverted to, and their simple 

 combinations, as so far resulting from intuition, that it can in general be more 

 readily acquired by early practice, than other actions of the same complexity ; 

 so that we may consider these movements as having somewhat of the same 

 consensual character as that which has been attributed to the purely vocalizing 

 actions ( 611). But there is in many individuals a deficiency of the power 

 of rightly combining them ; from which Stammering and other imperfections 

 result. 



618. Many theories regarding the nature of Stammering have been pro- 

 posed ; and there can be little doubt, that the impediment may be attributed to 



* Hence it is easy to understand the substitution of t or </, for the English th, by foreigners, 

 f Tlie English ch is merely a comlimatinn of/ \viih nh ; thus chime might be spelt Is/ii/iie. 

 j The general classification pn.pnscd by Dr. M. Hull is here adopted, with some modifica- 

 tion as to the details. 



