The Evolution of the Sciences 



of electricity, and that the inertia of matter is 

 due to the electric charges which it bears. 



All this shows clearly that our attempts to 

 complete our original conceptions of matter have 

 not led to precise and coherent results. But we 

 are only at the beginning of our difficulties. 

 Matter, even with the addition of all possible 

 forces, is insufficient to explain many pheno- 

 mena. Let us, for example, consider light. We 

 know, beyond doubt, that between the earth, the 

 sun and the stars there is no trace of matter 

 except the very thin layers forming the atmos- 

 phere of these bodies, and we also know that 

 light is merely a vibratory movement, which is 

 propagated at the rate of 186,000 miles per 

 second. Thus, from the moment a ray of light 

 leaves Sirius until it reaches us eight years elapse. 

 During this long journey over the paths of the 

 heavens the light was no longer on the star, nor 

 was it in our atmosphere. Where was it then? 

 What has been vibrating? Thus our poor mind, 

 which has to struggle with problems above its 

 power, is compelled to imagine the ether, this 



medium which fills the universe and transports 



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