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249
EXPERIMENTS ON THE CATHODE DISCHARGE
III. HAVE THE CATHODE RAYS ELECTROSTATIC PROPERTIES ?
If we admit that cathode rays are only a subsidiary pheno-
menon accompanying the actual current, and that they do not
exert electromagnetic effects, then the next question that arises is
as to their electrostatic behaviour. For the experiments relating
to this the battery, unfortunately, was no longer available, and
I had to make use of the discharges of a small induction coil.
On account of their irregularity and suddenness these are very
ill adapted for electrostatic measurements. Hence the experi-
mental results are not so sharp as they otherwise might have
been; but the conclusion to
The
which they lead may certainly
be regarded as correct.
question at the head of this
section may be split up into
two simpler ones. Firstly:
Do the cathode rays give
rise to electrostatic forces in
their neighbourhood? Sec-
ondly: In their course are
they affected by external
electrostatic forces? By
cathode rays are here meant
such as are separated from
the path of the current
which produces them: to
prevent confusion we shall
call these pure cathode rays.
عقود
FIG. 33.
AB is the glass tube,
which the rays were
A. In seeking an answer
to the first question I made
use of the apparatus shown in Fig. 33.
25 mm. wide and 250 mm. long, in
produced. a is the cathode. All the parts marked ẞ are in
good metallic connection with each other, and such of them as
lie inside the tube form the anode. They consist, in the first
place, of a brass tube which nearly surrounds the cathode, and
only opposite it has a circular opening 10 mm. in diameter,