Ill 



PROBATION AND AETICULATION 



167 



m, n, I, which can be recognised in phonautographic curves. The 

 phonograms of r, according to Hensen and Winckler, exhibit 

 a rhythmical crescendo and decrescendo like the moderate beats of 

 a musical tempo. 



Consonants proper are distinguished from semivowels in being 

 invariably composed of sounds, while the accent never falls on 

 them, i.e. they never act as syllabic sonants. They form two 

 subgroups, according as they are accompanied by distinct laryngeal 

 tones, or not ; the first are called sounding (or median} consonants, 



FIG. 109. Articulation of da and gia. 

 (Luciani and Baglioni.) 



Fio. 110. Articulation of ca and ga. 

 (Luciani and Baglioni.) 



the second mutes. Both may be subdivided into occlusives or 

 explosives, and fricatives or spirants. 



Explosive consonants are produced by the sudden opening of 

 the oral cavity, owing to the pressure of the expiratory air. 

 Their formation accordingly involves the closure of the pharyngo- 

 buccal cavity at a certain point, in which sense only they are 

 occlusive or closing sounds. Some authors maintain that they 

 should be called explosive when followed by a vowel or semivowel 

 (as in ba, pi, de, te, bra, pla, dro, knu), and occlusive when preceded 

 by a vowel or semivowel (ab, ip, ed, ot, arb, alp, ord, onk). But 

 this a fallacy. Every one can demonstrate that even when 

 preceded by vowels or semivowels, the characteristic sound of an 

 explosive consonant is heard, not at the closure, but at the 

 reopening, of the cavity which has been momentarily closed. 



