PHYSICAL PARADOXES. 



one struck, it was impossible to imagine how 

 one atom could attract or pull another, unless 

 we imagined that they had hooked projections 

 a fantastic conception which would advance 

 us no further, since we should still have to 

 explain how the hooks could hold fast to the 

 rest of the atoms unless by the force of attrac- 

 tion, which thus would be invoked to explain 

 them instead of being explained by them. 



But now that we believe atoms to consist 

 of elaborate combinations of separately moving 

 units, comparable to solar systems, it is im- 

 possible to imagine an atom in any way pulling 

 or drawing its neighbour; and to explain how 

 atoms exercise that tendency to mutual ap- 

 proximation which we call attraction, we are 

 driven once more to suppose that they are in 

 some way removing or diminishing repulsion 

 between their faces, so as to allow greater in- 

 fluence to repulsions in their rear which tend to 

 drive them together. 



Thus there is every reason to believe that 

 attractions of all kinds, from that universal 

 influence of gravitation denned in Newton's 

 great law, to the manifestations of cohesion, 

 magnetism, and chemical combination, would 

 prove, if we could learn the nature of their 

 mechanism in detail, to be special cases of 

 removed or limited repulsion, allowing greater 

 effect to indirect or circuitous repulsions acting 

 from the rear. 



198 



