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while being in‘a fluid’ condition possesses one of the’ most prominent 
properties of'a’solid. ‘We.are required to ‘believe in a hypothetical 
substance which refuses to be bound down by the ordinary laws of 
matter. It looks suspiciously like a demand on blind Faith, which 
we have more than once been told, isin Science, the one umpardon- 
able sin. Still 
They all do say we must believe in Ether, 
And sure; they all are scientific men. 
‘So much for the nature of the Ether. ‘With respect to the move- 
ments in it, there are further wonders. ‘As before stated, it is the 
medium whereby light and heat are conveyed across the stellar dis- 
tances. ‘Light and radiant heat are now authoritatively declared to 
be nothing but wave motions, or more correctly I ought to say wave 
motions translated into consciousness. By one set of waves the 
nerves of Common Sensation are affected, and we are conscious of 
warmth ; by another the Optic nervous fibres only are acted upon, 
and we are conscious of light. Between the two is a mere differ 
ence of the rate of vibration. ‘I have already said that the Ether 
is essentially an unquiet sea; itis continually in a tremor, or 
shivering condition. ‘This is produced in the first place by those 
motions of the molecules of all material bodies’ to which reference 
was made in the first part of this paper. Men asked how our 
nerves could possibly be affected by the vibrations of the molecules 
of a body millions of miles away ; how did their effect travel across 
the intervening space? ‘A similar question had been asked ‘with 
regard to sound, ‘but that was easily answered; it was soon dis- 
covered that air was necessary for its transmission, and that sound 
could not travel across a vacuum. A few simple experiments 
showed that air was not necessary to the transmission of light or 
heat, and the Ether was invented chiefly to provide a medium by 
which they might travel through space. As with sound then, we 
get waves ; not aerial, but ethereal; so minute that vibrations or 
tremors describes them better. In talking of these we have’ to deal 
with high numbers. It is doubtless known to you that when the 
middle C of a pianoforte is sounded, the strmg vibrates 256 times’a 
second; the next C above, 512 times, the next, 1025. ‘If the 
instrument have seven octaves, the lowest note being C, the upper- 
most note would by caused by 4096 vibrations per second. ‘These 
may seem very high rates of rapidity, but they quite fade away into 
nothingness when we come to ethereal vibrations which produce 
the sensation of light. The lowest number which can affect the 
optic nerves is 458 billions per second. Once more Iask you‘not 
to let this vague number slip by unregarded, but to- dwell upon it 
for a minute for two. ‘Try to conceive of 468 millions of millions 
