Human Frame, 23* 



labyrinth, and cochlea ; and thus all re- 

 fractions and modulations of the exter- 

 ternal air become perceptible, and conse- 

 quently all the different sounds they con- 

 vey become audible, and intelligible to 

 the mind, by the communication of these 

 nerves with the brain, or common sensory* 



That which is conveyed into the brain 

 by the ear, is called sound, though in 

 truth, till it come to reach and affect the 

 perceptive part, it be nothing but motion* 



The motion which produces in us the 

 perception of sound, is a vibration of the 

 air, caused by an exceeding short, but 

 quick, tremulous motion of the body from 

 which it is propagated ;*' and therefore we 

 consider and denominate them as bodies 

 sounding. 



That sound is the effect of such a 

 short, brisk, vibrating motion of bodies 

 from which it is propagated, may be 

 known from what is observed and felt in 

 the strings of instruments, and the tremb- 

 ling of bells, as long as we perceive any 

 sound come from them ; for as soon as 

 that vibration is stopped, or ceases in 

 them, the perception ceases also. 



Of Smelling. Smelling is another 



