Richmond dispatch. [volume] (Richmond, Va.) 1884-1903, 1896-03-29

and their phenomena. He also related
some of the scientific researches which
led up 10 the discovery OF the X-rays,
and continued: Professor Crookes found
that by exhaustng the glass tubes to a
very high degree. and increasing the po-
tentiai Of the electric current. an en-
tirely different set OF phenomena is pro-
duced. The dark space separating the
glow from the negative pole increases
In width, and across this space electrified
molecules are projected In parallel
paths normally from the surface Of the
cathode, giving eff what are called the
cathode-rays.
1.-THE molecules appear to be electrically
repealed SO strongly that they are
able to drive back TO certain
distance the body Of air still
in the tube. but the result of the jostl-
ings and collisions or bombardment Of
the molecules Is that they finally take
up their rectilinear motion. and convert
II into the vibratory motion OF luminosity.
When the vacuum attains to one
one-millionth of an atmosphere. so
that the dark space reaches the walls
OF the tube. the molecules continue their
rectilinear motion. until stopped by the
glass, where the impact produces beau
tiful phosphorescent light. The cathode
becomes more heated than the anode,
and particles of metal are torn off and
projected across the tube. A disk placed
IN the line OF the cathode discharge be-
comes positively electrified by these rays
and It has been found that the dis
charge is independent Of the metal used
rs a cathode. and independent Of the
position of the anode, in fact. similar
phenomena have been observed In vacu-
49,, tphoo xxitbatt qlaPfrOdpQ
RAYS DISCOVERED.
"ff OPAQUE or even transparent bodies
be placed in front Of these rays shadows
will DO thrown upon the glass back or
them, as II they stopped some OF the n.y.
ing molecules and prevented them from
striking the glass. This is Beautifully
shown I'm the Maltese Cross type of the
Cookies tube Professor Crookes regard
ed this cathode discharge as exhibiting
matter in an ultra gaseous or radiant
state. which could be detected by mag
net. and in other ways showed the cleo
trhcaton that seem to exist therein. be-
having like flexible conductors. But II
is 10 Professor Heinrich Hertz. Of Bonn,
lately deceased and more especially to
his assistant. Philip Lenard, now OF
Breslau, in Germany. that we are In
ma of these cathode-rays.
"Lenard found that these cathode rays,
though incapable of passing through the
glass wall of the Crookes tube, might
pass through thin sheets Of metal, such
as aluminium, when made part OF the
vacuum chamber. though the metal, Of
course, was opaque 10 ordinary light, and
in his paper published in the London Elec-
trician of March and April, 1894, made
known the fact that these rays could
penetrate a considerable distance from
such an aluminium window in a Crookes
tube. and were capable of causing phos-
phorescence In much the same manner
as when they fell upon substances within
the tube. and were also capable OF acting
upon Photographic plates He also showed
that these rays. were not only capable
of passing through the aluminium window
of the Crookes tube, but that they were
propagated through a vacuum made so
high that no electric discharge could pass
through. In other words. when the rays
were set up in the Crookes tube by an
electric current, they might enter a much
higher vacuum incapable Of carrying an
electric discharge and traverse such
higher medium. From this he reasoned
that the phenomenon was some effect
Of the ether.
PROF. ROENTGEN'S IMPRESSIONS.
Such" said the lecturer, was the
situation when Professor Roentgen made
his announcement to the world on the
4th of last January, that In addition TO
this phosphorescence other rays were pro-
duced capable of penetrating all bodies,
though not to the same extent, these rays,
he believed 10 be longitudinal vibrations
in the ether Of extremely minute length;
and In view OF the fact that his paper
sums up fully, yet concisely, his many
experiments and furnishes the most in
telligible and comprehensive description
OF the X-rays as yet published-to which
hut little has been added by the many
investigators OF the subject, until within
the last week or ten days, 1 shall read
the paper in full, for II is striking ex-
ample Of the thoroughness OF German
methods and thought" Mr.. Leonard then
read the paper, which In part was as fol-
lows:
"If we pass the discharge from large
Ruhmkorff coil through a Hittorf or
Observation-Disclosures Lenard. Crookes. or
similar apparatus, and cover the tune
with a somewhat closely-ftting mantle
of thin black cardboard. we observe In
a completely darkened room that paper
screen washed with -platino-c cyan
ide lights up brilliantly, and huoresces
equally well, whether the treated side or
the other be turned towards the dis
charge tube. Fluorescence is still observa-
bic two meters away from the apparatus.
IL IS easy TO convince ones self that the
cause of the fiuorescence is the discharge
apparatus and nothing else. The most
striking feature of this phenomenon is
that an influence (Agens) capable or exclt-
ing brilliant fuorescence is able TO pass
through the black cardboard cover, which
transmits none OF the ultraviolet rays OF
the sun or OF the electric arc. and one
Immediately inquiries whether other bodies
possess this property. 1t is soon discov-
cred that all! bodies are transparent
TO this influence. but in very
different degrees. A few examples
will suffice Paper is very transparent;
the fuorescent screen. held behind
bound volume of 1000 pages still lighted
up brightly, the printers ink offered no
perceptible obstacle. Fluorescence was
also noted behind two packs of cards: a
few cards held between apparatus and
screen made no perceptible difference. A
single sheet OF tinfoil is scarcely notice
able: only after layers have been laid
on top Of each other is a shadow clearly
Visible on the screen. Thick blocks OF
wood are also transparent: fir planks
Sm. 10 en-. thick. are but very slightly
OPAQUE A film of aluminium about Is nm.
thick weakens the effect very considera-
bly,, though II does not entirely destroy
the fuorescence. Several centimeters OF
vulcanized India rubber let the rays
through 0or brevity's sake / should like
10 use the expression rays" and TO
distinguish these from other rays. l will
call them 'X-rays.D Glass-plates OF the
same thickness behave in a different way,
nr a ia o. a eel