72 Proceedings of Royal Society of Edinburgh. [sess. 
But Koenig* has given a different valuation of the pitch, 
thus : — 
Vowels, . . 
. ou 
0 
A 
E 
i 
Tone, . . . 
• si[, 2 
si b 3 
S % 
Si t>6 
No. of vibs., . 
. 235 
470 
940 
1880 
3760 
Donders, f who was the first to observe that the cavity of the 
mouth for different vowels is tuned to different pitches, gave u 
as f, o as d, a as b'^ 6 (like oo in too) as g 2 , u (like aw in knaw) 
as a", e as c'", and i as f'". 
Again, we may sing a vowel on a scale, and still one can recog- 
nise the vowel in each note. Thus, if we sing a, or o , or i, on a 
scale beginning with c, the ear catches the sound of a , or o, or i in 
each note. Such tones are termed vowels, or we might call them 
vowel-tones. 
Theories of Vowel-Tones. — The investigation of vowel-tones may 
he considered to date from the experiments of Willis , % about 1829, 
who imitated vowels by means of a reed, above which he placed 
a resonating cavity ; and his conclusions are very similar to 
those put forward by Hermann at the present day. About 1837, 
Wheatstone § made some observations, and gave a theory. In 
later times, the subject has been studied by Donders, Helmholtz, 
Koenig, Hermann, and many others. 
The invention of the tinfoil phonograph by Edison in 1877, 
and the improvement of the instrument by the labours of Edison, 
Graham Bell, and others in more recent years, until we now pos- 
sess, in the wax-cylinder phonograph, an almost perfect mechanism, 
have led to the reinvestigation of the whole question of vowel-tone 
by Fleeming Jenkin and Ewing, Hermann, Pipping, Boeke, Lloyd, 
M‘Kendrick, and others. The difficulties in the way of account- 
ing for some of the phenomena of vowel-tones will be appreciated 
when we state that competent observers, such as those above 
named and many others, are ranged in two camps, — those who 
* Koenig, Comptes rendus des seances de VAcademie des Sciences , 1870, 
t. lxx. p. 931 ; also Quelques experiences d’Acoustique, 1882, p. 47. 
f Donders, De plnysiologie der SpraalcJclanJcen, 1870, p. 9. 
+ Willis, Cambridge Philosophical Transactions , 1829, vol. iii. p. 231 ; 
also Poggendorffs Annalen der PhysiTc , vol. xxiv. p. 397. 
§ Wheatstone, Westminster Review , Oct. 1837. 
