NEW CONCEPTIONS IN SCIENCE 



this manner that theories reveal their value. They 

 are to be judged largely by their fruit, and already 

 the corpuscular theory has proven fruitful. 



Professor Thomson draws attention likewise to 

 the application that Arrhenius, the Swedish phys- 

 icist, has already made to some very familiar hap- 

 penings. As Professor Thomson has been at pains 

 to show, all incandescent bodies give off corpuscles. 

 The sun we conceive as incandescent. Is the sun, 

 therefore, a gigantic cathode, negatively charged, 

 sending off into space in every direction myriads of 

 millions of millions of these little carriers? So it 

 appears. Some of these would strike the upper 

 regions of the earth's atmosphere, and thus come 

 under the influence of the earth's magnetism. The 

 corpuscles would describe a kind of a spiral, and 

 these would travel along the line of the earth's 

 magnetic force. As they pass northward or south- 

 ward to the poles they would be bent down follow- 

 ing the magnetic dip, and we should have then a 

 simple explanation of the aurora borealis. 



In a similar way the luminous character of comets 

 might be explained, and Arrhenius has even gone 

 so far as to calculate the enormous pressure which 

 these cathode rays would exert in a space around 

 the sun. Here we should have an explanation of 

 the reason why comets, when shooting round the 

 sun, turn their tails away from the sun instead of 



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