affinity. All these observations fascinate us, and fill us with an
intense desire to know more about the nature of these phenomena. Each
day we go to our work in the hope of discovering,--in the hope that
some one, no matter who, may find a solution of one of the pending
great problems,--and each succeeding day we return to our task with
renewed ardor; and even if we _are_ unsuccessful, our work has not
been in vain, for in these strivings, in these efforts, we have found
hours of untold pleasure, and we have directed our energies to the
benefit of mankind.

We may take--at random, if you choose--any of the many experiments
which may be performed with alternating currents; a few of which
only, and by no means the most striking, form the subject of this
evening's demonstration: they are all equally interesting, equally
inciting to thought.

Here is a simple glass tube from which the air has been partially
exhausted. I take hold of it; I bring my body in contact with a wire
conveying alternating currents of high potential, and the tube in my
hand is brilliantly lighted. In whatever position I may put it,
wherever I may move it in space, as far as I can reach, its soft,
pleasing light persists with undiminished brightness.

Here is an exhausted bulb suspended from a single wire. Standing on an
insulated support. I grasp it, and a platinum button mounted in it is
brought to vivid incandescence.

Here, attached to a leading wire, is another bulb, which, as I touch
its metallic socket, is filled with magnificent colors of
phosphorescent light.