240 THE HUMAN BODY. 



not make even a noise, a murmur; but they give a peculiar 

 character to a vowel sound. We find something in the 

 playing of an instrument analogous to this function of a con- 

 sonant. If we pinch the string of a violin, or strike a bell 

 with a hammer, a sound is produced which we imitate with 

 the voice by prefixing a / or d, as dinn, tinn; if the string or 

 the bell be made to vibrate with the bow, the sound as re- 

 produced by the vocal organ is preceded by the letters cr, 

 whence the imitative French word crin-criu. The hammer 

 and bow are the consonants, the note of the bell or the violin 

 is the vowel. 



Helmholtz has demonstrated, as we have already observed 

 in speaking of hearing, that the timbre of sounds is deter- 

 mined by the harmonics. He was able by means of ingeni- 

 ous instruments to decompose the sounds which only produce 

 a single sensation, and which seem to us simple, though they 

 are really composed of elementary sounds more or less 

 numerous. This analysis enabled him to discover the laws 

 under which the quality of the sounds is constituted which 

 are emitted by the glottis, and resound in the vocal tube 

 under the form of vowels. Among the elementary sounds 

 composing the sound emitted by the glottis, the vocal tube 

 exalts a particular one by preference, and it is this one 

 which gives to the vowel its characteristic timbre. The vocal 

 tube disposes itself in a special form for each vowel. It 

 lengthens or shortens, dilates or contracts; it places itself, in 

 a word, in conditions essential to the strengthening of the 

 sound which determines the timbre. Each vowel is there- 

 fore characterized by a note, but each one has a particular 

 affinity for certain notes; it is sometimes difficult, or even 

 impossible, to give such a note on another vowel than that 

 with which it corresponds, and thus singers are sometimes 

 forced to substitute one vowel for another. 



In seeking in the different qualities of the voice, and 

 especially in the vowels, for the seat of the resonance of 

 sounds in the buccal tube, and the parts which co-operate in 

 this resonance, Fournie has made a classification of the 

 letters, which he claims to have rendered more exact and 

 more anatomical than any of his predecessors. The tongue, 



