io6 SCIENCE AND IMMORTALITY 



making ether do all it is supposed to do without 

 endowing it with contradictory properties. 



Still, it is a working hypothesis of great value ; 

 and all the greatest physicists of the day use it to 

 unify and explain physical facts, and to many it 

 appears to have a more real existence than matter 

 itself. If it verily be the medium of light, and 

 heat, and electricity, and gravitation, its impor- 

 tance cannot be overestimated. Without it — on 

 this hypothesis — we should be in a dark, dead 

 world ; nay, there would be no world at all ; for 

 matter, if there be matter apart from it, would be 

 dissipated into infinite space. 



How did the hypothesis originate '^ Someone 

 remarked that it was " made in England " ; and 

 Sir Oliver Lodge supplements the remark with 

 the suggestion that it was largely constructed in 

 the Royal Institution. No doubt the idea had 

 floated about for many centuries ; but it was 

 Newton and Hooke who gave it force and fixity, 

 and brought it " through the Horn Gate of 

 dreamland into the region of reality." 



Newton had shown that throughout the whole 

 universe all particles of matter attracted each other 

 in accordance with a fixed law. The earth attracts 

 the falling apple ; the sun attracts the earth ; and 

 so on ad infinitum across the millions and millions 

 of miles of empty space. Now the question 



