6 REPORT—1904. 
which separates 1804 from 1904, and attempt to give in outline the worlde 
picture as it now presents itself to some leaders of contemporary specu- 
lation, 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 tnatter, the kinetic theory of gases, and the laws of the con- 
servation 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.! It was 
known, and had long been known, that such things as amber and glass, 
when ‘electrified’ by friction, could be made to attract light objects 
brought into their neighbourhood ; yet it was about fifty years before the 
effects of electricity were perceived in the thunderstorm, It was about 
100 years before it was detected in the form of a current. It was about _ 
120 years before it was connected with magnetism; about 170 years 
before it was connected with light and ethereal radiation. 
But to-day there are those who regard gross matter, the matter of 
everyday 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 sub-atoms 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, com- 
pared with such astronomical processes as the cooling 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 systems 
of electrical monads, what are these electrical monads? It may be that, 
as Professor Larmor has suggested, they are but a modification of the 
universal ether, a modification roughly comparable to a knot in a medium 
which is inextensible, incompressible, and continuous. But whether 
this final unification be accepted or not, it is certain that these monads 
cannot be considered apart from the ether. It is on their interaction 
with the ether that their qualities depend; and without the ether an 
electric theory of matter is impossible. 
Surely we have here a very extraordinary revolution. Two centuries 
ago electricity seemed but a scientific toy. It is now thought by many 
to constitute the reality of which matter is but the sensible expression. 
» The modern history of electricity begins with Gilbert, but I have throughout 
confined my observations to the post-Newtonian period. 
