XIII
245
EXPERIMENTS ON THE CATHODE DISCHARGE
that the actual current-lines could never cut the sides of the
vessel, as the lines in our drawings do.
The figures show without any doubt that the direction of
the cathode rays does not coincide with the direction of the
current. In some places the current-lines are almost perpen-
dicular to the direction of the cathode rays. Some parts of
the gas-space are lit up brilliantly by the cathode light,
although the current in them is vanishingly small. Roughly
speaking, the distribution of the current in its flow from pole
to pole is similar to what it would be in a solid or liquid
conductor. From this it follows that the cathode rays have
nothing in common with the path of the current.
1. Against the preliminary experiment the objection may
be raised that since a
magnet deflects the
cathode rays, conversely
the cathode rays must
deflect the magnet. But
when we come to con-
sider the expression "a
magnet deflects this or
that ray," and the com-
parison thus set up with
the deflection of an
elastic wire traversed by
a current, we may well
doubt whether these are
so suitably chosen as at
first sight they appear

FIG. 32, c (nat. size).
to be. Such a wire when the current starts would be
straight, and would only be brought into its deflected
position after a finite time. But we know that cathode
rays, even when the corresponding discharges last less than a
millionth of a second, appear completely bent.¹ De la
Rive's experiment in which the discharge is made to rotate
about a magnetic pole tells against the supposition that
electromagnetic action can set gaseous discharges in motion
with such speed as this. In De la Rive's experiment the
action is undoubtedly electromagnetic; but it takes place at a
1 See Goldstein, Über eine Form der elektr. Abstossung, iii. Teil.