eutral 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
the same direction, we can imagine two ways in which the action
proceeds: either the supply of gaseous molecules at the surface of the
negative pole must run short and the phenomena come to an end, or the
molecules must find some means of getting back. I will show you an
experiment which reveals the molecules in the very act of returning.
Here is a tube (Fig. 14) exhausted to a pressure of 0.001 millimeter
or 1.3 M. In the middle of the tube is a thin glass diaphragm, C,
pierced with two holes, D and E. At one part of the tube a concave
pole, A', is focused on the upper hole, D, in the diaphragm. Behind
the upper hole and in front of the lower one are movable vanes, F and
G, capable of rotation by the slightest current of gas through the
holes.

[Illustration: FIG. 14--PRESSURE = 0.001 MM. = 1.3 M.]

On passing the current with the concave pole negative, the small veins
rotate in such a manner as to prove that at this high exhaustion a
stream of molecules issues from the lower hole in the diaphragm, while
at the same time a stream of freshly charged molecules is forced by
the negative pole through the upper hole. The experiment speaks for
itself, showing as forcibly as an experiment can show that so far the
theory is right.

This view of the ultra-gaseous state of matter is advanced merely as a