PHYSICAL AND LITERARY, i^^ 



The mechanical a(5^ion and rea(5lion of 

 matter, or the changes, with regard to mo- 

 tion and reft, which take plaice in the co'I- 

 liliohs of non-elaftic bodies, have been al- 

 ready coniidered, and were found to be 

 intirely confifterit with the moft ablolute 

 inertia. But, that real actions, and equal 

 oppoiite rea(5tions, obtain in thd adtive 

 powers of attraction aiid repulfion, is a- 

 greeable to perpetual experience, and is 

 no lets certain, than that thefe powers 

 themfelves are eftablifhed in nature. We 

 find the loadftone attrafts iron^ and that 

 ifon attracts the Ibadftone, with equal 

 force ; and, becaufe they attract each o- 

 ther equally, they remain at reft when 

 tliey come into contact. If a mountain, 

 by its gravity, prelTed upon the earth, 

 and the earth did not reaCi equally on the 

 mountain, then the mountain would ne- 

 ceftarily carry the earth before it, by its 

 preilare, with a motion accelerated in in- 

 Jinltum. The fatne is to be faid of a ftone, 

 or the lead part of the earth, as well as of 

 a mountain. A mutual attracftion too is 



Vo L . I. U obferved 



