1152 The Relations of Mind and Matter. [ December, 
reality and substantiality of the luminiferous ether.” And he 
proceeds to say that it is the only thing we are confident of in 
dynamics. This ether he describes as an elastic solid, its rigidity 
enormous in proportion to its density. As to whether it pos- 
sesses weight or not he declares that there is no evidence for or 
against. 
J. Clerk Maxwell speaks as strongly on the subject, and finds a 
new use for the ether, as the medium of electric and magnetic 
energy. He advances a theory, which has met with much favor, 
that “light is an electro-magnetic phenomenon.” In other 
words, both these modes of traveling energy employ the same 
medium and are carried by it with a rapidity extraordinarily 
greater than any known movements of vibrations in matter, 
such as the waves of sound. Ether; therefore, is supposed to 
permeate all substances, however dense. It conveys electricity 
through the densest solids, and light through the densest 
transparents. -We can reduce air, by the air pump, to one 
hundred thousandth of its volume, and yet it is firmly held 
in a glass vessel. But light passes through the vessel, and 
through its partial vacuum, without a check, The substance 
which carries it moves as freely as if no other substance was 
present. 
There is, however, a seeming relation between matter and 
ether, if we accept the latest atomic theory, that of vortex mo- 
tion, propounded by Sir William Thomson. It is not necessary 
here to explain this theory ; it will suffice to say that it holds 
that fragments of the ether possess a vortical motion by which 
they become separate and indestructible integers. Each such 
vortex atom must have always existed and must always exist. 
They are indestructible and unchangeable. No new ones can 
arise, and no old ones can vanish. They must be coéternal with 
ether. Their substance is the same as the ether itself. They are 
simply portions of ether affected with a certain mode of motion. 
_ But as thus constituted they are essentialty distinct from ether, 
= and the two constitute two unlike conditions of substance. This 
conclusion i is probably true whatever the character of atoms, and 
' r the vortex atom theory be correct or not. 
Teer Oliver Lodge gives the following particulars con- 
th this substance The density of ether, though small, is 
i aii l its Functions, ae Jan. 25, 1883. 
