The Princeton union. [volume] (Princeton, Minn.) 1876-1976, 1896-05-14
I SOURCE OF tx" RAYS.
CONCLUSIONS Arrived at by an Emiza.-
s szs ent English Scientist.

Conclusions Arrived at by an Em1za.-
8=# ent English Scientist.
AS to the source Of the rays, I, like
others, have made many experiments,
and the results are definite enough.
When the rays from the cathode, in-
side the vacuum, impinge first on a.
glass surface, then that surface is.
the source. It is not as If the cathode
rays penetssted the glass and proceed
ed on their path; it Is not as if the.
glass surface were wave front, from
every point of which a ray penetrates:
normally; the glass radiates x rays.
just as a red-hot surface radiates light
From every point a cone of rays starts
in all directions, and there is no mu-
9tual interference in the lateral direc
tons, as there would be between a
number of similar sources all Of the.
same phase. Every point of the glass
radiates independently. like hot sur
face, in fact. The best experiments
of this kind were those in which
used a magnet to defect the cathode
rays on to any chosen spot or patch.
of the glass, and then took shadow
photographs through Sits and holes
placed at measured distances. The
shadows of wires at distance from
the plates, taken through narrow
slit at some distance from the wire,
show that if the x radiation consists
of waves at all those waves must be
very small. There has been nothing,
as yet, to discriminate between Tongi--
tudinal and transverse oscillations
Transverse must be considered as the
most probable at present; but then it.
is not certain that they are waves at
all. If waves. they must be very small
ones, and the question whether they
are transverse or longitudinal is al
most a miner consideration if it should
turn out that the wave length is COM
parable to the size of molecules. The
interest and Importance of such an
instrument Of investigation as radia-
ton with that size of wave whereby
indirectly MOLECULES themselves would
hereafter be rendered iffractionally
visible are immense
When the cathode rays do not first
strike the glass, but first strike a.
piece of metal enclosed in the bulb
then it's. behavior depends largely on.
what it is connected to. My expert
ments on this point are not complete,
but this much is certain. that if the
bomharded piece of metal is attached
to the cathode, so that it is unable to
receive any electrical discharges from
the cathode stream, then it either de-
clines to act as source of rays at all,
or else emits a radiation Of the most
feeble kind. which can without diff
Guilty be attributed to a secondary
cause. But on the other hand, if the
bombarded disk be connected with the
anode, so as to be able to receive the.
negative charges of the cathode.
stream, then it acts as a most vigorous
source. In low state of vacuum1
every part of the bulb keeps perfectly
cool, and the whole energy supplied
seems to pass off in x rays.
The crop of assertions about the de-
lection of x rays from all manner OF
absurd sources has somewhat dwin-
died Of late, and the loss is a bearable.
one. A serious attempt must be made
to observe if the sun emits them by
exposing suitable objects, such as bull
let's embedded in cork, in front of pro-.
tected plates, on mountain tops. this
summer. The atmosphere, being
equivalent to over two feet of mercury,
must entirely screen these rays from
lower levels; but Alpine tourists have
often reported a strange Jogging of
| plates, which they have been disposed
to attribute to the warmth of a guides;
back.-Prof. Oliver Lodge, in the Lon
| don Electrician.