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A VIS INERTIAS

to speak more truly, proper to it as matter:

and

Dr. Clarke arguing against Mr. Coltns, fays, “ This< c proportion it is that evidently thews gravitation not" to be caused by material impulse. And unless you“ [Mr. Coltns] could have found out an hypothesis,“ whereby either the quantity of solid matter in bodies,tc and the quantity of their superficies, could be made“ one and the same; or upon mechanical principles,“ bodies could, by superficial contact, receive impulses“ proportional to the quantity of solid matter contained" in them ; you would much more advantageously to" your self, have acknowledged the first palpable er-ror, than by a heap of things besides the purpose," have endeavoured to amuse only such readers as“ want skill in mathematics,” This is in his fourthdefence of an argument, to prove the immateriality ofthe soul, &c. p. 244. And in his third defence, p. 183.he fays : ‘‘ It has been demonstrated even mathemati-“ cally, that gravitation cannot arise from the consigu-" ration and texture of the parts of matter, and from“ the circumambient impelling bodies ; because, if it did,ff it would not be proportionable to the quantity of“ matter, or the solid content of all bodies, without<c any regard to their superficial proportion, as we findby experience it is ; seeing all bodies, of all textures,« and all configurations of parts, and all varieties of fu-" perficial proportion, (a bullet, or a feather, or a piece" ofleaf-gold, ora sneet of paper), descend invacuo with<c equal swiftness. And if material impulse be not thecause of gravity ; then some Being that is not ma t*« £ ter (for laws, or powers, are nothing but empty

" words)