STUDIES OF MATTER AND LIFE. 
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motion, not purely wave motion, it comes to us in a wave 
motion from the sun, conveyed like light by a material so 
attenuated as almost to reach the supposed condition of spiritual 
existence. This ether of space, wnich we can neither see nor 
feel, approximates to the conception, if such can be formed, of an 
immaterial substance. It must be so thin, and so light, that 
an inconceivable quantity would be required to weigh a pound, 
and yet when in motion the marvellous speed of its oscillations 
enables it to exert gigantic force. It can act so mildly that we 
are utterly unconscious that any substance strikes our eye when 
we see, or have a sensation of, violet light, in consequence of 
700 million millions of its minute waves dashing against it in a 
second. But light can also cause chlorine and hydrogen to 
rush together with enormous force, and it can instantly tear to 
pieces chemical compounds held together by forces equivalent 
to prodigious mechanical powers. 
Professor Josiah Cooke reckons that if this ether (of whose 
existence he is not quite satisfied) were as dense as common 
air, it would resist pressure on each square inch of seventeen 
million million pounds, just as air balances one of about 15 lbs. 
without suffering compression. He also tells us that if we 
could confine ether in a cylindrical vessel of sufficient strength 
to bear the pressure, and put upon it “ a cubic mile of granite 
rock, it would only condense the ether to about the same 
density as that of the atmosphere at the surface of the earth.” * 
In consequence of its wonderful elasticity, ether can convey 
light waves about a million times quicker than air can convey 
sound waves, and some of the pulsations that reach us from the 
sun, and which lie beyond the violet end of the visible spectrum, 
must make their extremely short wave oscillations much quicker 
than the 700 millions of millions of violet light. Should, con- 
trary to probabilities, the theory that space is filled with ether, 
and that ether has the properties mentioned, be ultimately 
found untenable, the measures of wave lengths and wave veloci- 
ties must still refer to something positively existing. Light 
comes to us from the sun at the rate of about 190 1 millions 
of miles in a second, whatever it is ; and when physicists say 
a wave of red light is about — ^ of an inch long, and a violet 
one about — ^ long, no doubter of the existence of ether, like 
Professor Cooke, hesitates to assume that they are quantities of 
* “The New Chemistry,” p. 23. 
t The exact distance can never he known, as some residual error is un- 
avoidable. When all the Transit of Venus calculations are finished and 
compared with the experimental methods adopted in Paris, the average 
result will probably be not far from 190 millions. 
