' the Physiology of the Human Voice. 273 



by Galen*, Boethius, Fabriciiisf, MarcienneJ, Kircher, Pei'- 

 rault§, and many others ||. 



Dodart^ also at first embraced the Aristotelian hypothesis 

 respecting the velocity of the air in the aperture of the glottis, 

 but finding it insufficient, he adopted a new theory, which, 

 owing to its elaborate researches, has obtained the greatest 

 attention . 



His theory, however, of the parabolic curves of the glottis, 

 the whistle, and the vox humana pipe of the organ, were by 

 no means happy deductions from his researches. 



Ferrein** has proved by experiment that the vocal chords 

 are capable of yielding all the tones of the voice, and has endea- 

 voured to show that their tension regulates the modulations, 

 and that they are governed by the same laws as stringed mu- 

 sical instruments- 

 Mr. Willisft also appears to be of the same opinion as Fer- 

 rein with regard to the tension of the vocal ligaments. He 

 observes, " To obtain the various notes from the glottis, 

 therefore, it is only necessary to vary its longitudinal tension 

 after the ligaments have been placed in the proper position." 



M. Savart, whose valuable researches have contributed 

 greatly to our acoustic knowledge, conceives that the superior 

 and inferior ligaments of the glottis form an apparatus analo- 

 gous to the duck-whistle Jt? ^"'^ that all the variations of the 

 glottis are regulated upon the same principle as that instru- 

 ment, a view which has been adopted by several physiologists 

 of the present day. 



A consideration of these diversified and unsatisfactory the- 

 ories induced me to reinvestigate this subject, and for this 

 purpose to repeat the experiments of Ferrein. In the first 

 place, I observed, that in order to produce any sounds what- 

 ever, it was requisite to close the chink of the glottis §§, by 

 bringing the edges of the vocal ligaments into immediate con- 

 tact, when, by straining them tolerably tight, the sounds be- 



• Galen, Opera, Be Larynge, lib. 7- 



+ De Larynge, Vocis Organo. X Harmonie Universclle. 



§ Essais de Phydque ; Traite du Bruit. 



Jl Casseriiis, ZJc Organo Vocis, Sfc. 



t Minn, de PAcad. Royale, 1700, 1707- ** Ibid., 1747- 



■f i Cainb. Philos. Trans., vol. iv. 



XX f I'e transverse sections of the larynx in figg.4. and 5. give an appear- 

 ance not unlike the duck-whistle, which is a small circular bos, perforated 

 in the centre by two holes, situated opposite to each other : according to 

 the hypothesis of Savart, the tones of the voice would have rather resem- 

 bled tlic whistle than the reed. 



4§ Liscovius {loc. cit., p. 29-34.) confirms this remark. lie says that 

 no tones arc formed where the glottis is very much diluted. 

 Third Series. Vol. 9. No. 54. Oct. 18.3G. 2 I 



