448 THE POPULAR SCIENCE MONTHLY 
had written a treatise on electricity which few could read and no one 
could fully understand. A distinguished French physicist said he 
understood everything in Maxwell’s book except what was meant by a 
body charged with electricity. Maxwell had given us but a vague idea 
of electric displacements and displacement currents, because his ideas 
were bound up in equations without experimental verification, or even 
illustration. 
Then came Hertz’s researches which confirmed the fundamental 
hypotheses of the Faraday Maxwell theory and “ annexed to the domain 
of electricity the territory of light and radiant heat.” “ Many think- 
ers,” said Lord Kelvin,’ “have helped to build up the nineteenth-cen- 
tury school of plenwm, one ether for light, heat, electricity and magnet- 
ism; and Hertz’s electrical papers, given to the world in the last de- 
cade of the century, will be a permanent monument of the splendid 
consummation now realized.” Some one has said that Hertz en- 
throned Maxwell in every chair of physics in Europe and America. 
It appears that many of the ancient philosophers had a shadowy 
idea of a medium in space, which they personified, and called “ father.” 
According to Heriod Auther was the son of Erebus and Night and the 
brother of Day. The Orphic hymns speak of Aither as the soul of the 
world, the animator of all things, the principle of life. The children of 
Z®ther and Day were the objects about us, the heavens with all their 
stars, the land, the sea. Adther was the lightest and most active form 
of matter and Day had the power of converting it into heavier matter. 
Plato speaks of the ether as being a form of matter far purer and 
lighter than air, so light that “ its weight can not be ascertained because 
distributed through infinite space.” 
During the fifteen years following the publication of Hertz’s 
researches, it is probable that greater homage was paid to ether by 
modern physicists than was ever given it by the ancients. The ether 
was appealed to from every quarter. Light, radiant heat and electric 
waves were ether waves. An electric charge was an ether strain. An 
electric current was a phenomenon in the ether and not in the wire in 
which it appeared to flow. Magnetism and gravitation were phenom- 
ena of the ether. Matter itself became an aggregation of ether vor- 
tices. Ether and motion were expected to explain everything. Such 
terms as natural philosophy and physics were discarded by some of our 
text-book writers who adopted such titles as “matter, ether and 
motion ”; “ ether physics ”. “ ether dynamics ”: “the mechanics of the 
ether.” Physics was defined as the science of motion. 
The classical mechanics of La Grange was built on what were con- 
+n his treatise on mechanics published in 1894, endeavored to eliminate 
sidered fundamental concepts—mass, force, space and time. Hertz, 
1Kelvin, introduction to Jones’s translation of Hertz’s “ Electric Waves.” 
Maemillan, 1893. 
