254 Human Frame. 



norous bodies by means of the ail- ; and 

 the external part of the ear is so contriv- 

 ed, by its ridges and hollows, that sounds, 

 being gathered into it as into a tunnel, 

 are thereby directed to the meatus audi- 

 torious, through -which they pass and 

 strike upon a thin transparent membrane 

 of an oval figure, set a little obliquely 

 across the passage of the ear ; behind 

 this membrane there is a pretty large ca- 

 vity, which, with the said membrane, 

 from its resemblance, is called the tympa- 

 num, or drum of the ear. In this cavity 

 are four small bones, which from their 

 form are called malleolus, or the hammer ; 

 the incus, or the anvil ; the shapes* or 

 stirrup ; and the os orbicculure, or circu- 

 lar bone. Within the tympanum there 

 are several other cavities, as the vestibu* 

 him, the labyrinth, and the cochlea ; these 

 Internal cavities are always full of air ; 

 wherefore the sounds in the external air 

 striking on the drum, move the four lit- 

 tle bones in the tympanum, and these in 

 like manner move the internal air, which 

 maketh an impression on the fine bran- 

 ches of the auditory nerve spread through 

 the vestibulum, the winding tubes of the 



