[Illustration: FIG. 13 A.--PRESSURE = 0.0001 MM. = 0.13 M.]

[Illustration: FIG. 13 B.--PRESSURE = 0.0001 MM. = 0.13 M.]

[Illustration: FIG. 13 C.--PRESSURE = 0.0001 MM. = 0.13 M.]

As the exhaustion proceeds, the positive charge in the tube increases
and the neutral point approaches closer to the negative pole, and at a
point just short of non-conduction so greatly does the positive
electrification preponderate that it is almost impossible to get
negative electricity from the idle pole, unless it actually touches
the negative pole. This tube is before you, and I will now proceed to
show the change in direction of current by moving the idle pole.

I have not succeeded in getting the "Edison" current incandescent
lamps to change in direction at even the highest degree of exhaustion
which my pump will produce. The subject requires further
investigation, and like other residual phenomena these discrepancies
promise a rich harvest of future discoveries to the experimental
philosopher, just as the waste products of the chemist have often
proved the source of new and valuable bodies.


PROPERTIES OF RADIANT MATTER.

One of the most characteristic attributes of radiant matter--whence
its name--is that it moves in approximately straight lines and in a
direction almost normal to the surface of the electrode. If we keep
the induction current passing continuously through a vacuum tube in