170 PHYSIOLOGY CHAP. 



is expressed by a special sign. It is not, in fact, a series of sounds, 

 but a single continuous sound very similar to s, formed by con- 

 striction of different parts of the oral cavity. It is due to 

 application of the lateral edges of the tongue to the hard palate, 

 alveoli, molar teeth, allowing an escape of air through a median 

 passage between the tip of the tongue and palate, which is wider 

 and more posterior than in s (Figs. 113, 114). 



X. The words of a language result from the different combina- 

 tions of the elementary sounds we have been dealing with 

 vowels, semivowels, sounding and mute consonants. One or two 

 vowels, alone or accompanied by semivowels or consonants so as 

 to make a continuous phonetic unity, form the so-called syllables. 

 The phonetic continuity of the syllable depends on its being 

 pronounced in one uninterrupted breath, which is only possible 

 when its elements are capable of fusion or agglutination. When 

 the successive sounds are not capable of agglutination, so as to 

 be uttered in a single, continuous, expiratory effort, a short 

 interruption or pause (the hiatus} is interposed between them, by 

 which the sound is divided into two or more syllables. 



The coherence of two vowels forms a diphthong ; when they 

 make a single syllable, i.e. fuse together so that the voice is 

 not interrupted in the rapid transition from the position for the 

 first to that for the second vowel; when, on the contrary, two 

 vowels follow without agglutinating, so that the voice is interrupted 

 in passing from one to the other, they do not form part of the same 

 syllable and do not constitute a diphthong (aid, poetry}. The 

 division of two normally agglutinated vowels by the interposition 

 of a hiatus is known as diuresis ; the fusion of two separate vowels 

 which form part of two successive syllables, as synaresis. In the 

 first case one of the syllables is made into two, in the second two 

 syllables are fused into one. 



More frequently the syllable consists of one vowel or diphthong 

 and one, two, or three semivowels or consonants, and vice versa. 

 Two laws must be observed for the adhesion of a vowel with 

 semivowels and consonants : (a) Vowels readily adhere to semi- 

 vowels, imperfectly to explosives and fricatives-; (6) Both 

 semivowels and consonants agglutinate perfectly with vowels to 

 form single syllables. 



The combination of several syllables constitutes polysyllalic 

 words, in which the phonetic unity is interrupted once or oftener, 

 according as it consists of two or more syllables. The break 

 is produced by the discontinuity of the outgoing expiratory 

 blast due either to occlusion or narrowing of the resonating 

 cavity at some point along its course glottis, soft palate, hard 

 palate, or lips. The interruption may be more or less appreci- 

 able according as it is more or less prolonged, and is not always 

 a complete silence, but may be a light aspiration the tennis 



