PREFACE. 



IN the primitive ages of the world, when men 

 gazed on the wonders of nature with the fresh- 

 ness of childhood, and before the vivid infor- 

 mation of the senses had become obscured by 

 fabulous traditions, all their physical and me- 

 taphysical theories were founded on the belief 

 that solar fire is the efficient cause of motion 

 and life throughout creation. This belief, 

 so manifestly the result of observation and 

 experience, was constantly forced upon their 

 minds with all the evidence of a living reality ; 

 and prevailed for thousands of years in every 

 quarter of the habitable globe. Nor is there 

 anything so strikingly obvious to the unso- 

 phisticated common sense of mankind, as the 

 omnipresent influence of the sun, which is 

 perpetually exerting a tranquil, yet omnipotent 

 energy, throughout the air, the ocean, and 

 the solid ground. He regulates all the phe- 

 nomena of climate and season, evaporation 

 and rain, the circulations of the atmosphere, 



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