308 SIR CHARLES BELL ON THE ORGANS OF THE HUMAN VOICE. 
ening and elongation of the pharynx and mouth. To allow the cavity to be 
shortened in the greatest degree, the larynx is raised, and the lips retracted ; 
on the contrary, the trachea descends, and the lips are protruded, to lengthen 
the cavities, and to give out the lower or graver notes. 
Of Articulation. 
In pronouncing the simple continued sounds, the vowels, and the diphthongs, 
which are the combinations of open sounds, the pharynx, at all times irre- 
gular, varies its form or dimensions, without interrupting or cutting the 
sounds. These sounds are universal and expressive. What we have now to 
consider are more conventional, and form the constituents of articulate lan- 
guage. 
It has been imagined that the vocalized breath ascending into the mouth is 
there divided, and articulated by the tongue, teeth and lips ; and that this 
comprehends the whole act of speech. Such a description implies a very im- 
perfect acquaintance with the actions which produce articulate language. 
It is now my purpose to show, that in articulating, or forming the conso- 
nants, the pharynx is a very principal agent ; and that this smaller cavity is 
substituted for the larger cavity of the chest, to the great relief of the speaker, 
and the incalculable saving of muscular exertion. 
The late Dr. Young made a comparison of the power employed by a glass- 
blower, in propelling the air through his tube by the force of his cheeks, and 
in propelling it by the force of his lungs ; and calculating the ease with which 
the lesser cavity is compressed in comparison with the greater, — that is, the 
cavity of the mouth compressed by the muscles of the cheeks, compared with 
the whole extent of the chest compressed by the muscles of respiration, — he 
concluded, that the weight of four pounds would produce an operation through 
the lesser cavity, equal to seventy pounds weighing on the larger cavity. 
The quality of fluids, by which they transmit pressure equally in all direc- 
tions, is the cause of this and of some other results which appear paradoxical. 
It is a property too nearly allied to mechanical power, and too important to 
be left out of the scheme of animal structure. 
When a forcing-pump is let into a reservoir, it produces surprising effects. 
The piston of the hydraulic press being loaded with a weight of one pound, the 
