

THE 



POPULAR SCIENCE 



MONTHLY. 



MAY 1902. 



THE ELECTRONIC THEORY OF ELECTRICITY. 



By Dk. J. A. FLEMING, F. R. S., 



PROFESSOR OF ELECTRICAL ENGINEERING, UNIVERSITY COLLEGE, LONDON. 



CONSIDERABLE progress has been made of late years in our 

 knowledge concerning the structure and relations of atoms and 

 electricity. Recent discoveries have moreover placed in a new light old 

 theories and experimental work. The remarkable investigations and 

 deductions made from his own experiments and those of others, which 

 have led Professor J. J. Thomson to the conclusion that atoms can be 

 split up into, or can give off, smaller masses, which he calls corpuscles, 

 were explained by him in a most interesting article in the Populab 

 Science Monthly for August, 1901.* There seems to be good evi- 

 dence that in a glass vessel exhausted to a high vacuum through the 

 walls of which are sealed platinum wires, we have a torrent of small 

 bodies or so-called corpuscles projected from the kathode or negative 

 wire, when the terminals are connected to an induction coil or elec- 

 trical machine. 



Twenty-five years ago Sir William Crookes explored with wonder- 

 ful skill many of the effects due to electric discharge through such high 

 vacua, and came to the conclusion that they could only be explained 

 by the supposition that there was present in the tube matter in a 

 fourth state, neither solid, liquid, nor gaseous, but 'radiant matter 7 

 projected in straight lines from the surface of the negative pole or 

 kathode, the particles moving with immense velocity, and all charged 



* See Popular Science Monthly, Vol. LIX., p. 323, ' On Bodies Smaller 

 than Atoms,' by Professor J. J. Thomson, F.R.S. See also by the same 

 author a paper in the Philosophical Magazine for December, 1899, ' On the 

 Masses of the Ions in Gases at Low Pressures.' f -^ _- r» py O 



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