324 Mr Willis on the 



nomena, in as much as they are produced by a part of the animal 

 frame, has been consigned, with that of its other functions, to the 

 Anatomist and Physiologist, to those whose professional studies 

 are completely unconnected with Acoustics, a science which in 

 all investigations of this kind must necessarily take the greatest 

 share. 



Accordingly every treatise on Physiology or Anatomy contains 

 a chapter on the organs of voice, in which the parts conducing to 

 its formation are described ; whilst the contradictory and some- 

 times careless accounts which the best anatomical writers give of 

 the mechanical action of these parts, and of the mode in which 

 they perform their functions, form a vexatious contrast with the 

 minute accuracy of their anatomical descriptions. 



In the present memoir I have attempted a more minute analysis 

 of a part of these organs than appears to have been hitherto un- 

 dertaken. As, however, I am writing for philosophical readers 

 in general, I have purposely divested my descriptions of the tech- 

 nical form as much as possible, and my drawings are to be regarded 

 more as plans or types of the general structure gathered from the 

 examination and comparison of many, than as representations of 

 any one individual. 



The vocal mechanism may be considered as 



_ „ . Variable 



consisting ot Lungs or Bellows, capable ot trans- Cavity. 



mitting by means of the connecting Windpipe a Larynx 

 current of air through an apparatus contained in the 

 upper part of the Windpipe, which is termed the g- 



Larynx. This apparatus is capable of producing ?■ 



•■' re 



various musical notes which are heard after passing : 



Lungs, or 



through a variable cavity, consisting of the pharynx, Bellows. 

 mouth, and nose. 



