A TREATISE 



into the caufes thereof; come to difcerne that thefe effects are 

 not wrought by the intervention of ayery qualities;but by reall 

 and material! applications of bodies to bodies ; which indif- 

 ferent manners do make the fame results within us. 



But when I fuftefed my pen to bee Peered by my fanfie.that 

 pleafed it felfe, and noted in the remembrance of thefe two no- 

 table perfbns : I was fpeafong, how the ftrong continuity of the 

 parts of a thing that is moved,draweth on the motion, and con- 

 fequendy the fbund.much further then where that which is mo- 

 ved fuflfereth breaches , or the rarity of it occafloneth that one 

 part may be moved without an other 5 for to the proportion of 

 the fliakingjthenoife continueth. As we fee in trembling bells, 

 that hum a great while longer then others , a frer the Clapper 

 hath ftrucken them : and the very found feemeth to quiver and 

 fliake in oureares, proportionable to the making of the beJJ, 

 And in a Lute as long as a firing that hath been flrucken , fha- 

 keth fenfibly to our eye 5 fb long, and to the fame meafure , the 

 f(j>und mat eth in our eare. Which is nothing elfe hut an undu- 

 lation ofthe Ayre', caufed by the fhia'rt and thick vibrations of 

 the corde^and mukipiyed in the belly ofthe inftrument (which 

 is the reafbn that the concave figure is affected in moi\ ) andfo 

 when it breaketh out of the instrument in greater quantity, 

 then the firing immediately did make - y it caufeth the fame un- 

 dulations in the whole body of Ayre round about. And that, 

 ftriking the Drum of the eare, giveth notice therein what te- 

 nour the firing moveth : vvhofe vibrations if one flop by laying 

 his finger upon it^the found is inttamly at an end, for then there 

 isnocaufeonfoot, that continueth the motion of the Ayre : 

 which,without a continjation of theimpulfc, returneth fpeedi- 

 dily to quiet; through the refinance made unto it, by other parts 

 of it that are further off. 



Out of all which itisplaine, that motion alone is able to 

 efteit and to give account of all things whatfbever that are at- 

 tributed to found ; and that found and motion , do goe hand in 

 hand together ; and that whatfbever is faid of the one , is like- 

 svile true ofthe other. Wherefore it cannot bedenyed but that 

 hearing is nothing elfe but the due perception of IBM*'** : and that 

 motion aud fo**d are in themfelves one and the fame thing, 

 r hcu t',h expreftcd by different name*, and comprifed in our un- 



derftanding 



