PHYSICAL ANE> LITERARY. 2^ 



Op the communication 

 OF MOTION. 



'Tp H E communicatiea of motion from 

 -* one body to another, has been ex-* 

 tremely puzzling to metaphyfidans ; tho* 

 not to pra(5lical philofophers, who make 

 na difEcuky to fuppofe, that motion ac* 

 tually pafTes out of one piece of matter 

 into another. Let us figure one billiard 

 ball at reft, and another diredled upon it 

 with a certain velocity. It is underftood 

 that part of the motion of the impin- 

 ging ball pafTes into that which is at reft, 

 after which it proceeds to move with that 

 degree of velocity which is communicated 

 to it. This account of the matter ap- 

 pears to me altogether abfurd. Motion 

 cannot fubfift by itfelf, to be transferred 

 from place to place, or from body to bo- 

 dy. It is one of the qualities or proper- 

 ties 



