PHYSICAL AND LITERARY. 41 



the refifting body itfelf, to preferve it 

 from motion* And, if this refiftance 

 fhall be conceived as a counter-adion,' 

 ■which it may be in a loofe way of think- 

 ing ; I cannot however conceive any e- 

 quality betwixt the prefTure of my hand 

 and this fuppofed counter-adlion of the 

 ftone. At this rate, the counter-a6lion 

 of the ftone is equal to every degree of 

 imprefFed force, provided the imprefTed 

 force be not great enough to move the 

 ftorie ; and fo it will be equal at the fame 

 time to a thoufand different degrees of 

 force. To talk of the equality of acftion 

 and reaction in fuch a cafe, means really 

 nothing iliore than that the hand has not 

 force enough to move the ftone. 



Again, if the obftacle be moveable, it 

 coincides with another inftance given, 

 that of percuffion, or the collifion of haf^; 

 bodies. Here indeed it is true, that there 

 is as much force loft by the one body, as 

 is generated in the other. But then this 

 is plainly the effedl of the vis reftjientlie, as' 

 explained above j and therefore it is un!* 

 philofophical to introduce any other prin- 

 VoL.I. F cJpie 



