COSMIC PHILOSOPHY 



resists motion is known by us only under the 

 twofold form of attraction and repulsion, which 

 may be either polar or universal. Polar attrac- 

 tion or repulsion is that which acts with differ- 

 ent power in different directions. An example 

 of polar attraction is to be found in every case 

 of crystallization, where molecules are grouped 

 into a solid figure bounded by plane surfaces ; 

 and a familiar example of polar repulsion is 

 that which is exhibited when the positive poles 

 of any two magnets are brought into mutual 

 proximity. Universal attraction or repulsion is 

 that which acts with equal power in all direc- 

 tions. In universal attraction we are accustomed 

 to distinguish three modes, respectively called 

 gravity, cohesion, and chemism or chemical 

 affinity. 



The essential difference between these modes 

 of primary force and the various modes of 

 motion is illustrated by the familiar facts that 

 gravity causes molar motion while molar mo- 

 tion does not cause gravity ; and that chemism 

 gives rise to the species of molecular motion 

 called heat, while heat cannot give rise to chem- 

 ism, though it may result in a molecular rear- 

 rangement which will allow chemism to manifest 

 itself. For example, gravity causes a spent rocket 

 to fall to the ground ; but the upward motion 

 of the rocket does not cause gravity, although 

 it results in a position of the rocket which en- 

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