The San Francisco call., 1896-02-18

those rays he might have seen before him
the skeleton of the professor of physics as
one might see iron or wooden bones in
glass manlkin when the white sunlight
shone through it.
But now don't think that this pretty
hight, the vibrations that the human eye
is capable of perceiving, would have any
thing to do with the Roentgen photo
graph. Scientists would have said so,
until Roentgen accidentally discovered
something the other day, that arrange
ment of battery, induction coil and
vacuum was setting up different kinds of
vibratory motions that variously rolled
out through the surrounding ether, air
and solid substances as big turbine
wheel, for instance, might cause all sorts
of heavy and light, slow and rapid, shak-
lngS through the water and the mill. If
that arrangement had been set up before a
scientist few centuries ago the only phe-
nomenon he would have perceived would
have been the glow of light, because the
particular vibrations producing it are the
only ones of the lot that man happens to
have sense TO perceive.
Since a century and more ago when man
learned by experiment to recognize the
electric current by its effect on something
besides sense, the ordinary force of the
electric current would have been recog-
nized In that simple arrangement of Pro-
fessor Sanford's.
That makes two things th at would have
been the limit of the forces of nature
which man would have perceived that ar
rangement on the laboratory table setting
into activity up to very few years ago.
Then Hertz found new sort OF vibrations
proceeding from an induction coil and es-
pecially from the neighborhood of an elec-
tric discharge and these are now called
Hertzian waves. They are not light, heat,
or the electric current. They are vinra-
tlons that flow outward from their source
like light from thing that glows. and IN
TIL Hertz stumbled on them so recently
nobody ever dreamed that such things
were bustling about in the universe. These
HertZian waves Professor Sanford knew to
be In operation there.
And now comes Professor Roentgen
with the discovery that from this arrange
ment described there proceeds what is be-
ieved TO be kind of vibration more dis
tlnct from the other sorts than the Hertzian
waves are from light. No sense can per-
ceive 1t, and it is being recognized and
studied by its effects, noticed now for the
first time. 1t illustrates how little man is
capable of perceiving. This was the way
Professor Sanford talked over his Crooke's
tube:
There are many peculiar phenomena
which take place in Crooke's tube, and
they have been studied for about fifteen
years. Ii the air is entirely exhausted
there can be no spark produced in one.
They are generally exhausted to from the
one-thousandth to the one ten-thousanth
part of an atmosphere. The end of the
wire connected with the negative pole of
the battery is called the cathode, and the
effect appears to proceed from the cathode
W hen the current is started the particles
OF rarefed gas are electrified and driven off
from the cathode with great force.
"lf there is sufficient gas it becomes
luminous through the particles striking
each other. When the particles can reach
the walls of the tube and pound against
them, they set up a fluoreseence in the
glass. Probably they cause the glass to
set up light vibrations in the ether. The
cathode rays are not the y rays of Roent-
gen, nor are they rays OF light. They are
the steams of gas particles as they are
repelled from the cathode, and it is rather
their effect which is talked about.
"If l put certain substances near this
tube they will likewise huoresce as has
been known for some time. IL has not
been known that the cathode rays would
produce the same effect when the fiuores-
cence was hidden, though it had been dis
covered that when tiny sheet of alumni
mum is set in the tube like a pane OF glass
the cathode rays striking on this OPAQUE
window would produce fiuorescence in q
proper substance placed behind it.
'Roentgen accidentally discovered in
his laboratory that sheet of paper moist
ened with double cyanide OF barium and
platinum and lett near a Croeke's tube
when the tube was covered with a black
cloth would show fuorescent effects, show
ing that the cloth was transparent to the
cause of the huorescence He followed
this discovery with his experiments The
effects secured can hardly be explained by
any knowledge or theories held before
The rays from the Crooke's tube, which
produced Roentgen's new tuorescent ef-
fects and later his photogra phic effects
a fter passing through wood and flesh, are,
OF course, not light, and they are not
Hertzian waves evidently. His theory is
that the gaseous particles, striking against
the glass, produce vibration which sets
up waves or vibrations in the ether diff
ferent from any other kind of motion. He
thinks that they are longitudinal ether
waves.
I'VE have no sense that enables us to
take cognlZance of the ether as We can of
light and heat, but we know that light
and radiant heat are vibrations in an elas-
tic medium, and we call that medium the
ether. 1t must pervade all bodies, because
some form OF radiation can pass through
all bodies at a velocity far greater than it
would be if the bodies them selves trans
mltted It, The ether is as real to physicists
as matter. Ne know only one kind of
ether waves, and they are now all included
In the term radiation. We know no limit
to their lengths. One very small octave
IN the range of wave lengths we can per-
celve by the eye as light.
Now, every kind OF ether waves or vi
brations that we know anything about
can be reflected, refracted and polarized.
We also know that all the kinds of ether
waves with which we are acquainted are
transverse vibrations; that is the yibra-
tons are back and forth across the line or
plane OF motion, like waves in water or in
a rope when it is shaken, or like the vibra-
tions OF a string. When we speculate
a about ROantoan's ravs bajno lon c,,+nd;,oI