The herald., 1896-12-06

ing. The rays which produce this Won
derful effect are not very luminous, In
fact they may not be luminous at all;
yet they produce luminosity; the matter
Is still in dispute. The English school
considers them material electrified par
ticles, proceeding in straight lines; the
contending authorities insist that the
rays are similar to those of light, trans
verse undulations in ether. So you see,
it is almost the same dispute, which
proved so vexatious to the ancients.
AS have stated, heat also like light,
consists of undulatory movements IN
the ether, but not of so high a frequency
and we know photographs have been
taken in a dark room by the heat radi =
ated from a pot of boiling water, but
not through Opaque bodies. l will utl
ize the storage battery and the induc-
ton coil which l have shown you, and
not the Tesla apparatus, for my expert
ments with these Xrays
We have here an ordinary bell jar
containing air, attached to this air
pump. 1t has two wires leading into
it that are called electrodes. and to dis
tinguish them, that by which the cur
rent enters Faraday called the anode;
that by which it leaves the cathode
Each electrode exhibits different prop
critics when the current is passing. For
example: small particles of metal may
be torn off from the anode or negative
eleclrOOe, ana projected from 1tS sur
face ;or small particles of air or mole
cules in the bulb may be violently dis
charged from the anode. When a cur
rent of electricity is passing through the
air in the jar, and when the air is
gradually pumped out you will notice
the character of the discharge changes
In different gases the effect differs.
After the exhaustion has been carried
to a certain point it is more difficult for
the current to pass In hydrogen gas
under like conditions the spark is twice
as long as in the air. To make a spark a
mile long, virtually a lightning flash,
il is calculated that something like one
billion ordinary telephone batteries
would be required: so you will see that
we are dealing with very high pressures.
You will also see the spark less sharp
ly defined and wdened out to occupy
! more space giving us beautiful glow.
The negative electrode exhibits blush
or violet color separated from the cleo
trode by narrow dark space, to which
/ wish to call your special attention.
You will see how the character of the
current varies in the vacuum, as it is
made more and more nearly complete.
Some years ago when Prof. Crookes
began the study of these effects of hign
vacuum he found that If the glass bulb
was exhausted Of air to very high de-
gree curious effects were produced when
the electric current was passed.
Here is "Crookes tube" exhausted
| to about lilo, 900 of the pressure of the
atmosphere; when the electric charge
passes through it the remaining air be-
comes luminous. The absence of lumiu =
osity around the negative electrode in
the middle of the tube is called the neg
ative dark space; there is no fiuorescence
around the glass in this bulb. nor any
! X rays produced. This negative dark
| space is of great interest to u.s. as it is
| supposed to be the seat of the X rays.
| l will show you some of Crookes' ex-
periments which tend to prove this. The
first one will be tube nearly free from
air, containing a small wind mill sup
ported upon a pivot. The second rail-
way tube, so-called. They are acted
upon and set in motion by the discharge.
| This gives us some idea that if space is
not too full of matter the particles have
more room to act in, and so can obtain 4
higher velocity and do more work when
| they meet with any object in their way.
| Acting like bullets from repeating rifle.
| they impinge upon the object upon
which they are directed. producing mo-
ton, heat and light. In these expert
ments, you see, they produce motion,
| the next experiment will show you that
| these particles produce heat by bonn
| bardment.
| In this experiment the discharge is
! focused like the rays of light by a
| metallic reflector and produces great
heat, heating the platinum disc upon
which they are thrown, red hot.
The fourth experiment will show you