PHTSIGAL AND LITERARY. 53 



than, that of a fluid circulating about the 

 fun, in which the planets are involved 

 and carried along, like a fhip in a torrent. 

 The ingenious Mapertuis, in his eflay up- 

 on attraclion, moves feveral objedions to 

 it, even as new moulded by later writers. 

 He objeds, in the firil place, that the pla- 

 nets do not move in a circle, but in an 

 ellipfe : In the next place, that they do not 

 move with celerities proportionable to 

 their diflances from the fun ; which they 

 behoved to do, if carried along in a vor" 

 l€x moving, like a wheel, equably round 

 the fun. Thefe objections are well found- 

 ed j but, in my apprehenfion, he has o* 

 verlooked the mod folid and weighty ob* 

 jedion. Whatever caufe can be affigned 

 for the motion of this fluid round the 

 fun, will equally account for the motion 

 of the planets, without neceflity of in- 

 troducing a nrw fund of matter, of the 

 iesiftence of which we have no evidence. 

 More particularly, m.otion is obvioufly 

 an efFedl which muft have fome caufe. 

 ,This caufe muft either be 9. continued in- 

 terpofition of a voluntary agent, or a pow- 

 er 



