THE PATH OF EVOLUTION 



ing bell was a sufficient reason for the sound that 

 reached the human ear. The theory that the air vi- 

 brations alone affected the ear that heard the sound 

 was considered foolishness and false, until, placing the 

 ringing bell in the air pump's vacuum, proved that 

 where there was no air there could be no sound. 

 There was a time when Sound did not exist on the 

 earth ere on its surface life appeared. When first 

 cooled from its fiery glow, " The wreck of matter 

 and the crush of worlds " undoubtedly gave origin to 

 the contraction and expansion of the aerial spheres 

 whose onward moving waves now carry Sound to the 

 ear. But the waves then died unheard. No ear ? 

 animal or human, existed to transmit their impulse, 

 and no brain to receive them. They would only be 

 " Winds that withered in the stagnant air," or beat 

 silently on the rocks and stones, for Sound is only 

 Sound when heard by the subjective brain ; in itself 

 it is only an aerial impulse, signifying nothing. 



The Electricity that was produced by rubbing pieces 

 of amber was early observed by the Greeks. Homer 

 in the " Odyssey," IV., 70, speaks of amber : " The 

 flashing of gold and of amber, of silver and of ivory." 

 The curious property it showed of attracting and re- 

 pelling small light particles obtained its name 

 Electricity from the Greek term for amber " Elec- 

 tron." The legend being that in the Baltic Sea am- 



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