MECHANISM OF SPEECH. 503 



pally into play ; the second tone may be entirely neglected ; the third ren- 

 dered very feebly ; the higher tones, particularly the fifth and seventh, being 

 added strongly. 



" These examples sufficiently illustrate the subject of vowel-sounds. We 

 may blend in various ways the elementary tints of the solar spectrum, produc- 

 ing innumerable composite colors by their admixture. Out of violet and red 

 we produce purple, and out of yellow and blue we produce white. Thus also 

 may elementary sounds be blended so as to produce all possible varieties 

 of clang-tint. After having resolved the human voice into its constituent 

 tones, Helmholtz was able to imitate these tones by tuning-forks, and, by com- 

 bining them appropriately together, to produce the clang-tints of all the 

 vowels. " 



Consonants. Some of the consonants have no sound in themselves and 

 serve merely to modify vowel-sounds. These are called mutes. They are J, 

 d, Jc, p, t, and c and g hard. Their office in the formation of syllables is suf- 

 ficiently apparent. 



The consonants known as semi- vowels are /, Z, m, n, r, s, and c and g soft. 

 These have an imperfect sound of themselves, approaching in character the 

 true vowel-sounds. Some of these, Z, m, n and /*, from the facility with 

 which they flow into other sounds, are called liquids. Orthoepists have far- 

 ther divided the consonants with reference to the mechanism of their pronun- 

 ciation : d,j, s, #, 2, and g soft, being pronounced with the tongue against the 

 teeth, are called dentals ; d, g, /, k, /, n, and q are called palatals ; Z>, p, /, v 

 and m are called labials ; m, n and ng are called nasals ; and &, g, and c and 

 g hard are called gutturals. After the description already given of the voice, 

 it is not necessary to discuss farther the mechanism of these simple acts of 

 articulation. 



For the easy and proper production of articulate sounds, absolute integrity 

 of the mouth, teeth, lips, tongue and palate is required. All are acquainted 

 with the modifications in articulation in persons in whom the nasal cavi- 

 ties resound unnaturally from imperfection of the palate ; and the slight 

 peculiarities observed after loss of the teeth and in harelip are sufficiently 

 familiar. The tongue is generally regarded, also, as an important organ of 

 speech, and this is the fact in the great majority of cases ; but instances are 

 on record in which distinct articulation has been preserved after complete 

 destruction of this organ. These cases, however, are unusual, and they do 

 not invalidate the great importance of the tongue in ordinary speech. 



It is thus seen that speech consists essentially in a modification of the 

 vocal sounds by the accessory organs, or by parts situated above the larynx ; 

 the latter being the true vocal instrument. While the peculiarities of pro- 

 nunciation in different persons and the difficulty of acquiring foreign lan- 

 guages after the habits of speech have been formed show that the organs of 

 articulation must perform their office with great accuracy, their movements 

 are simple, and they vary with the peculiarities of different languages. 



Whispering. Articulate sounds may be produced by the action of the res- 

 onant cavities, the lips, teeth and tongue, in which the larynx takes no part 



