of reservoir R was about 1-20, and the degrees of exhaustion reached
were necessarily very high, though I am unable to make a precise and
reliable statement how far the exhaustion was carried.

What impresses the investigator most in the course of these
experiences is the behavior of gases when subjected to great rapidly
alternating electrostatic stresses. But he must remain in doubt as to
whether the effects observed are due wholly to the molecules, or
atoms, of the gas which chemical analysis discloses to us, or whether
there enters into play another medium of a gaseous nature, comprising
atoms, or molecules, immersed in a fluid pervading the space. Such a
medium surely must exist, and I am convinced that, for instance, even
if air were absent, the surface and neighborhood of a body in space
would be heated by rapidly alternating the potential of the body; but
no such heating of the surface or neighborhood could occur if all free
atoms were removed and only a homogeneous, incompressible, and elastic
fluid--such as ether is supposed to be--would remain, for then there
would be no impacts, no collisions. In such a case, as far as the body
itself is concerned, only frictional losses in the inside could occur.

It is a striking fact that the discharge through a gas is established
with ever increasing freedom as the frequency of the impulses is
augmented. It behaves in this respect quite contrarily to a metallic
conductor. In the latter the impedance enters prominently into play as
the frequency is increased, but the gas acts much as a series of
condensers would: the facility with which the discharge passes through
seems to depend on the rate of change of potential. If it act so, then
in a vacuum tube even of great length, and no matter how strong the
current, self-induction could not assert itself to any appreciable
degree. We have, then, as far as we can now see, in the gas a