930 OP THE VOICE AND SPEECH. 



instruments, the acting length of the pipe is determined by the interval between 

 t^e embouchure and the nearest of the side apertures ; by opening or closing 

 which, therefore, a modification of the tone is produced. In the Organ, of which 

 the greater number of pipes are constructed upon this plan, there is a distinct 

 pipe for every note ; and their length increases in a regular scale. It is, in 

 fact, with flute-pipes as with strings that a diminution in length causes an 

 increase in the number of vibrations, but in a -simply inverse proportion ; so 

 that of two pipes, one being half the length of the other, the shorter will give a 

 tone which is the octave above the other, the vibrations of its column of air 

 being twice as rapid. Now there is nothing in the form or dimensions of the 

 column of air between the larynx and the mouth, which can be conceived to 

 render it at all capable of such vibrations as are required to produce the tones 

 of the Human voice ; though there is some doubt whether it be not the agent 

 in the musical tones of certain Birds. The length of an open pipe necessary to 

 give the lowest Gr of the ordinary bass voice is nearly six feet ; and the condi- 

 tions necessary to produce the higher notes from it are by no means those 

 which we find to exist in the process of modulating the human voice. We now 

 come to the third class of instruments, in which sound is produced by the vibra- 

 tion of reeds or tonyues ; these may either possess elasticity in themselves, or 

 be made elastic by tension. The " free" reeds of the Eolian, Accordion, 

 Seraphine, Harmonium, &c., are examples of instruments of this character, in 

 which the lamina vibrates in a sort of frame that allows the air to pass out on 

 all sides of it through a narrow channel, thus increasing the strength of the blast : 

 whilst in the Hautboy, Bassoon, &c., and in Organ-pipes of similar construction, 

 the reed covers an aperture at the side of one end of a pipe. In the former 

 kind, the sound is produced by the vibration of the tongue alone, and is regulated 

 entirely by its length and elasticity ; whilst in the latter, its pitch is dependent 

 upon this, conjointly with the length of the tube, the column of air contained 

 in which is thrown into simultaneous vibration. Some interesting researches 

 on the effect produced on the pitch of a sound given by a reed, through the 

 union of it with a tube, have been made by M. W. Weber; and, as they are im- 

 portant in furnishing data by which the real nature of the vocal organ may be 

 determined, their chief results will be here given. I. The pitch of a reed may 

 be lowered, but cannot be raised, by joining it to a tube. n. The sinking of 

 the pitch of the reed thus produced is at the utmost not more than an octave. 

 in. The fundamental note of the reed, thus lowered, may be raised again to its 

 original pitch, by a further lengthening of the tube; and by a further increase 

 is again lowered. IV. The length of tube, necessary to lower the pitch of the 

 instrument to any given point, depends on the relation which exists between 

 the frequency of the vibrations of the tongue of the reed and those of the 

 column of air in the tube, each taken separately. From these data, and from 

 those of the preceding paragraph, it follows that, if a wind instrument can, by 

 the prolongation of its tube, be made to yield tones of any depth in proportion 

 to the length of the tube, it must be regarded as a flute-pipe ; whilst if its pitch 

 can only be lowered an octave or less (the embouchure remaining the same) by 

 lengthening the tube, we may be certain that it is a reed instrument. The 

 latter proves to be the case in regard to the Larynx. 



982. It is evident from the foregoing considerations that the action of the 

 Larynx has more analogy to that of reed instruments than it has to that either 

 of vibrating strings, or of flute-pipes. There would seem, at first sight, to be a 

 marked difference in character, between the vocal ligaments and the tongue of 

 any reed instrument; but this difference is really by no means considerable. 

 In a reed, elasticity is a property of the tongue itself, when fixed at one end, 

 the other vibrating freely ; but by a membranous lamina, fixed in the same man- 

 ner, no tone would be produced. If such a lamina, however, be made elastic 



