° 
tion of two other quantities. 
DECEMBER 8, 1899. ] 
molecular distances through interplanetary 
and interstellar distances until we reach 
the mighty distances which bound the Uni- 
verse—all have their being in this wondrous 
ether. 
And yet, however wonderful it may be, 
its laws are far more simple than those of 
matter. Every wave in it, whatever its 
_ length or intensity, proceeds onwards in it 
according to well known laws, all with the 
same speed, unaltered in direction from its 
source in electrified matter, to the confines 
of the Universe unimpaired in energy unless 
itis disturbed by the presence of matter. 
However the waves may cross each other, 
each proceeds by itself without interference 
with the others. 
= So with regard to gravitation, we have no 
evidence that the presence of a third body 
affects the mutual attraction of two other 
bodies, or that the presence of a third quan- 
tity of electricity affects the mutual attrac- 
The same for 
magnetism. 
For this reason the laws of gravitation 
and of electric and magnetic action includ- 
ing radiation are the simplest of all laws 
when we confine them to a so-called vacuum, 
but become more and more complicated 
when we treat of them in space containing 
matter. 
Subject the ether to immense electrostatic, 
magnetic or gravitational forces and we find 
absolutely no signs of its breaking down or 
even of change of properties. Set it into vi- 
bration by means of an intensely hot body 
like the sun and it conveys many thou- 
sand horse-power for each square foot of sur- 
face as quietly and with apparently un- 
changed laws as if it were conveying the 
energy of a tallow dip. 
Again, subject a millimeter of ether to 
the stress of many thousand, nay even a 
million, volts and yet we see no signs of 
breaking down. 
Hence the properties of the ether are of 
SCIENCE. 
829 
ideal simplicity and lead to the simplest of 
natural laws. All forces which actata dis- 
tance, always obey the law of the inverse 
square of the distance, and we have also the 
attraction of any number of parts placed 
near each other equal to the arithmetical 
sum of the attractions when those parts 
are separated. So also the simpler law of 
etherial waves which has been mentioned 
above. 
At the present time, through the labors 
of Maxwell supplemented by those of Hertz 
and others, we have arrived at the great 
generalization that all wave disturbances in 
the ether are electromagnetic in their nature. 
We know of little or no etherial disturbance 
which can be set up by the motion of mat- 
ter alone: the matter must be electrified in 
order to have sufficient hold on the ether to 
communicate its motion to the ether. The 
Zeeman effect even shows this to be the case 
where molecules are concerned and when 
the period of vibration is immensely great. 
Indeed the experiment on the magnetic 
action of electric convection shows the same 
thing. By electrifying a disc in motion it 
appears as if the disc holds fast to the ether 
and drags it with it, thus setting up the 
peculiar etherial motion known as magne- 
tism. 
Have we not another case of a similar 
nature when a huge gravitational mass like 
that of the earth revolves on its axis? Has 
not matter a feeble hold on the ether suffi- 
cient to produce the earth’s magnetism ? 
But the experiment of Lodge to detect 
such an action apparently showed that it 
must be very feeble. Might not his experi- 
ment have succeeded had he used an elec- 
trical revolving disc? 
To detect something dependent on the 
relative motion of the ether and matter has 
been and is the great desire of physicists. 
But we always find that, with one possible 
exception, there is always some compensa- 
ting feature which renders our efforts use- 
