ejsentialto Matter, &c. 27

the powers of elasticity , gravity, repulsion ,&c. for in all these the moment is plain bythe effect produced. It is the effect pro-duced by the moment , or force, that shewsthe powers of elasticity, gravity, &c. theseimpulses should be otherwise undiscoverableby us: and it is the moment also that in-evitably shews the matter to be resisting rnat-rter in thesie very instances. So that there isno hazard of our being deceived in conclud-ing universally that all the tendencies to mo-tion observable, or possible to be observed,about matter, are not the powers of matter,or properties residing in it, or possible to beplanted in it by any being : but stricily im-pulses upon it ab extra.

XVII. However, let us suppose whatsome philosophers think not impossible,and lee how far it will influence this con-clusion ; viz. that the power of gravity inparticular may be the effect of some fluid,or very subtil matter,, impelling those bodieswe call heavy {ft} - and let the fame be

supposed

(h) Dr. Pemherton, ia his view of Sir If. Newionhphilosophy, fays, that great man himself conjectured tht S

might