44 THE CREATION OF MATTER 



fore, be everywhere a special element which forms the 

 vehicle for carrying from point to point those energies or 

 motions which are light-giving. This element, this ether 

 as it has been called, does not make its own existence 

 known to any of the senses. We do not see, we do not 

 smell, we do not taste it. It emits no sound. In no 

 way, even in its most rapid light-giving motions, does it 

 affect the sense of touch. We do not perceive it by any 

 of the means through which we become acquainted with 

 the existence of the elements of the chemical world. 

 The evidence, however, for its existence and mode pf 

 action in producing light is irresistible. It is strengthened 

 and confirmed by such an element being necessary for 

 the explanation of the phenomena of heat and electricity. 

 As light reaches us from the most distant nebulae, a vast 

 ether sea must fill the whole of known space, and be 

 continuous and the same throughout all its borders. 



The undulatory or wave theory may be illustrated by 

 what takes place when a stone is thrown into water. 

 The molecules struck are borne downward, and the level 

 is broken. The force of gravity comes into play, and 

 acts until the surface again becomes a horizontal plane. 

 Under its influence, the neighbouring molecules descend 

 to fill the depression caused by the stone. The next 

 molecules descend to fill their place, and the next move 

 in like manner. This goes on till those at the point first 

 depressed rise above their former level, and an elevation 

 is formed. This again descends, and an elevation appears 

 around it. Up and down the molecules rise and fall, 

 through shorter distances each time, till equilibrium and 

 a level is restored. Meantime the neighbouring molecules 

 have been moving up and down in the same manner, 

 and this movement has been propagated through the 

 water, and so waves have been made to circulate all 



