36 POPULAR SCIENCE MONTHLY 



With atoms broken up into corpuscles, the problem of the nature 

 of matter shifts one step farther back, and becomes the problem of the 

 nature of these tiny bodies. Of this problem two rival solutions are 

 now in the field, offered respectively by the conservatives and the lib- 

 erals. The former, while admitting that a corpuscle is in the main an 

 electric charge, or field of electric force, maintain that the charge has 

 a nucleus or carrier at its core, which alone is entitled to be called 

 matter, in distinction from the electricity of the charge. Lenard, who 

 has given to corpuscles the significant name of dynamides, has calcu- 

 lated the diameter of this center of actual matter, so called, and found 

 it to be smaller than 0.3 of 10 -10 , i. e., smaller than three hundred 

 thousand millionths of a millimeter. This means that the actual 

 matter, so called, of a cubic meter of so heavy an element as platinum, 

 occupies at most one cubic millimeter of space, the rest of the cubic 

 meter being empty of Lenard's matter, and in fact entirely empty of 

 ponderable matter, but for the electric charges. 



With so much of matter acknowledged to be electric force, which 

 to that extent successfully performs all the functions which used to be 

 attributed to matter, it is natural, say the liberals, to inquire whether 

 the whole of matter can not be reduced to force, whether matter is not 

 just force and nothing more. Many facts, they say, make this alto- 

 gether the more probable, indeed the only comprehensible, hypothesis. 



In the first place, as Sir Oliver Lodge, who shares with Professor 

 J. J. Thomson — another hard-headed Englishman — the distinction of 

 leading the liberals, points out, " an electric charge possesses the most 

 fundamental and characteristic property of matter, viz., mass or in- 

 ertia." 6 If the charges occupying a given space are sufficient, and 

 their potential is sufficiently high, their combined mass will equal, and 

 exhaustively account for, the observed mass of the matter occupying the 

 space. This conclusion was theoretically established long since, and 

 has recently received experimental confirmation from laboratory studies 

 on radio-activity. 



On these points, I quote the statement of Professor Bigelow, of the 

 University of Michigan: 



Long before experimental evidence of the existence of corpuscles had been 

 obtained, it was demonstrated that an electrically charged body, moving with 

 high velocity, had an apparent mass greater than its true mass, because of the 

 electrical charge. The faster it moved the greater became its apparent mass or, 

 what comes to the same thing, assuming the electrical charge to remain un- 

 altered, the greater the velocity the less the mass of the body carrying the 

 charge needed to be to have always the same apparent mass. It was calculated 

 that when the velocity equalled that of light, it was not necessary to assume 

 tliat the body carrying the charge had any mass at all ! In other words, the 

 bit of electric charge moving with the velocity of light would have weight 

 and all the properties of mass. 



This might be looked upon as an interesting mathematical abstraction, but 



6 Popular Science Monthly, August, 1903. 



