THE SMALLEST WORKERS 



move non- uniformly they produce electromagnetic 

 phenomena (for example, the waves used in wireless 

 telegraphy); if they move with periodic motion they 

 produce the waves of light. Meanwhile stationary ag- 

 gregations of electrons produce the so-called electro- 

 static phenomena. All the various ether waves are thus 

 believed to be produced by changes in the motions of 

 the electrons. A very sudden stoppage, such as is pro- 

 duced when the cathode ray meets an impassable 

 barrier, produces the X-ray. 



With these explanations in mind, it will be obvious 

 how closely this newest interpretation of electricity 

 corresponds in its general features with the old one- 

 fluid theory of Franklin. The efforts of the present- 

 day physicist have resulted essentially in an analysis of 

 Franklin's fluid, which gives to this fluid an atomic struc- 

 ture. The new theory takes a step beyond the old in 

 suggesting the idea that the same particles which make 

 up the electric fluid enter also into the composition 

 perhaps are the sole physical constituents of every 

 material substance as well. But while the new theory 

 thus extends the bounds of our vision, we must not claim 

 that it fully solves the mystery. We can visualize the 

 ultimate constituent of electricity as an electron one 

 thousand times smaller than the hydrogen atom, which 

 has mass and inertia, and which possesses powers of 

 attraction and repulsion. But as to the actual nature 

 of this ultimate particle we are still in the dark. There 

 are, however, some interesting theories as to its char- 

 acter, which should claim at least incidental attention. 



We have all along spoken of the electron as an ex- 

 [i57] 



