Manchester Memoirs, Vol. Hi. (1908), No. 10. 3 



masked by the contemporary presence of Newton — seemed 

 unable to accept the new doctrine in its full scope. To a 

 mind like his there could remain no question about the 

 chief Newtonian deductions : the evidence was conclusive 

 that the interactions through the aether of bodies far 

 apart in comparison with their magnitudes, and with 

 nothing between, must somehow adjust themselves into 

 the gravitational law of attraction. But he was unable 

 to understand how the complex mutual influence of 

 masses near together could possibly, in all cases without 

 exception, resolve itself into a result so uniform and so 

 simple. And to this day we remain largely in the position 

 of Huygens with regard to this subject. The evidence, 

 which in its beginnings enabled the genius of Newton to 

 detect and develope his cosmical system, has of course 

 long ago become overwhelming. Yet why is the gravita- 

 tional attraction of a particle of matter sunk at the centre 

 of the Earth entirely unaffected by all the intervening 

 mass ? We do not know, any more than Newton did, how 

 this action is transmitted. We may take refuge in the 

 idea that the nuclei in the aethereal medium, which 

 constitute the cores of the fields of activity known to us 

 as material atoms, must even in the densest matter 

 occupy a space absolutely infinitesimal compared with 

 the whole region of aether, and so not obstruct or 

 modify the transmission of the gravitative influence. To 

 get play for rational conceptions, we are thus thrown 

 back on the atomic theory of matter, and that in its more 

 modern physical aspect, to which it is now time to 

 pass on. 



It does not appear that Descartes was able to 

 penetrate to any idea of the relation of the cosmical 

 vortex to the atoms of the material bodies which it 

 carried round in its grasp ; they were merely like ex- 



