ON MATTER AND FORCE. 19 



the matter may be divided, yet each part will 

 have a part of the force, and there can be no 

 more of the force lost than of the matter. We 

 cannot think that the matter can exist without 

 the force of gravity being always acting or 

 ready to act in each atom of it. Nor can we 

 think that any portion of the force of gravity 

 can be separated from the matter. If we 

 mentally attempt to divide any amount of the 

 force into its constituent portions, then every 

 portion, however minute, of the force must 

 have a corresponding portion of matter to 

 which it is inherent, and without which the 

 force cannot be thought to exist. 



Newton's great discovery consisted in de- 

 termining the existence of force in each par- 

 ticle of the matter of the earth and the planets ; 

 and Adams and Leverrier, recognising the 

 action of a force not accounted for in the matter 

 that was known, predicted the existence of 

 unknown matter in an undiscovered planet 

 which was looked for and found. 



The great advance, however, towards the 

 modern stage of ideas regarding the insepara- 

 bility of matter and force is owing to Young 

 and Fresnel, who overthrew the second stage 



