SIR CHARLES BELL ON THE ORGANS OF THE HUMAN VOICE. 311 
In a person whom I had the pain of attending for a long time after the 
bones of the upper part of the face were lost, and in whom I could look down 
behind the palate, I saw the operation of the velum palati. Daring speech it 
was in continual motion ; and when this person pronounced the explosive let¬ 
ters, the velum rose convex, so as to interrupt the ascent of the breath in that 
direction; and as the lips parted, or the tongue separated from the teeth or 
palate, the velam recoiled forcibly. 
These facts lead us to the farther contemplation of the pharynx. We see it 
to be a large cavity behind the palate, formed by a dilatable bag, and acted 
on by many muscles. We have seen that the volume of sound issues into it 
from the glottis below; and that although it opens into the nose above, yet 
this passage is closed, whenever the velum is raised, like a valve, in the man¬ 
ner just described; at such a time, if the mouth be also shut, the bag will be 
closed on all sides, and may then suffer distention by the vocalized breath 
ascending through the glottis. 
In speaking, much of the sound, as of the vowels and diphthongs, is the 
uninterrupted issue of the vocalized breath, modulated by the passages, and 
differently directed, but not checked or interrupted. The consonants are the 
same sounds checked by the tongue, lips, or teeth. At the moment of this 
interruption, the pharynx, being distended, is prepared to give an appulse by 
its muscular action exactly in time with the parting lips. 
If we grasp the throat whilst speaking, so that the fingers embrace the bag 
of the pharynx, we shall feel that each articulate sound is attended with an 
action of the pharynx; and preceding each explosive letter, we shall be sensi¬ 
ble of a distention of the throat. By a close attention to the act of breathing, 
we shall perceive that whilst the distended chest falls gradually and uniformly, 
the bag of the pharynx is alternately distended and compressed in corre¬ 
spondence with the articulated sounds. 
We can now conceive that if each appulse of the breath in speaking arose 
from the action of the chest, it would be attended with great and unnecessary 
exertion; since in proportion to the size of the reservoir and the smallness of 
the tube that gives issue, would be the force required on the sides of the 
reservoir to produce an impulse along the tube. If each consonant and ac¬ 
cented syllable required the action of the whole thorax, we should find that a 
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