MANOMETKIC FLAMES. 403 



lower than the accompanying sound of the mouth- cavity, 

 or one vibration of the former corresponds to two vibra- 

 tions of the latter. The larynx-sound alone would then 

 produce a series of images like fig. 236 B, the sound of 

 the mouth-cavity alone a series' like fig. 236 A. But 

 together they give images like fig. 237 (9, which may 

 be considered as a combination of the two series of 

 images in fig. 236; every second image in J., fig. 236, 

 coincides with one of B in the same figure and produces 

 a larger flame, while between these enlarged flames, 

 which are due to the sum of the actions of the single 

 flames, there is a series of smaller flames which owe their 

 existence exclusively to the higher note produced simul- 

 taneously by the cavity of the mouth. 



If the vowel A (as in aJi) is sung on the note bb, the 

 images present the appearance of A in fig. 237. The 



FIG. 237 ( real size}. 



larynx-sound of the vowel A (#?") is two octaves 

 higher than #7; four vibrations of the sound of the mouth - 



D D 2 



