498 POPULAR SCIENCE MONTHLY. 



ception makes no response, like the electric waves of wireless teleg- 

 raphy,* intrinsically differ, not in kind but in magnitude alone. 



This, however, is not all, nor nearly all. If we jump over the 

 century which separates 1804 from 1904, and attempt to give in out- 

 line the world picture as it now presents itself to some leaders of con- 

 temporary speculation, we shall find that in the interval it has been 

 modified, not merely by such far-reaching discoveries as the atomic and 

 molecular composition of ordinary matter, the kinetic theory of gases, 

 and the laws of the conservation and dissipation of energy; but by the 

 more and more important part which electricity and the ether occupy 

 in any representation of ultimate physical reality. 



Electricity was no more to the natural philosophers in the year 

 1700 than the hidden cause of an insignificant phenomenon, f It was 

 known, and had long been known, that such things as amber and glass 

 could be made to attract light objects brought into their neighborhood ; 

 yet it was about fifty years before the effects of electricity were per- 

 ceived in the thunderstorm. It was about one hundred years before 

 it was detected in the form of a current. It was about one hundred 

 and twenty years before it was connected with magnetism; about one 

 hundred and seventy years before it was connected with light and 

 ethereal radiation. 



But to-day there are those who regard gross matter, the matter of 

 every-day experience, as the mere appearance of which electricity is the 

 physical basis: who think that the elementary atom of the chemist, 

 itself far beyond the limits of direct perception, is but a connected 

 system of monads or subatoms which are not electrified matter, but are 

 electricity itself; that these systems differ in the number -of monads 

 which they contain, in their arrangement, and in their motion relative 

 to each other and to the ether; that on these differences, and on these 

 differences alone, depend the various qualities of what have hitherto 

 been regarded as indivisible and elementary atoms; and that while in 

 most cases these atomic systems may maintain their equilibrium for 

 periods which, compared with such astronomical processes as the cool- 

 ing of a sun, may seem almost eternal, they are not less obedient to 

 the law of change than the everlasting heavens themselves. 



But if gross matter be a grouping of atoms, and if atoms be sys- 

 tems of electrical monads, what are these electrical monads? It may 

 be that, as Professor Larmor has suggested, they are but a modifica- 

 tion of the universal ether, a modification roughly comparable to a 

 knot in a medium which is inextensible, incompressible and continu- 



* First known through the theoretical work of Maxwell and the experi- 

 ments of Hertz. 



t The modern history of electricity begins with Gilbert, but I have through- 

 out coniined my observations to the post-Newtonian period. 



