of the utmost significance for human society, though not at all in the
way first hoped for.

Interest in the phenomena arising when electricity passes through gases
with reduced pressure had simultaneously taken hold of several
investigators in the seventies of the nineteenth century. But the
decisive step in this sphere of research was taken by the English
physicist, William Crookes. He was led on by a line of thought which
seems entirely irrelevant; yet it was this which first directed his
interest to the peculiar phenomena accompanying cathode rays; and they
proved to be the starting-point of the long train of inquiry which has
now culminated in the release of atomic energy.3

In the midst of his many interests and activities, Crookes was filled
from his youth with a longing to find by empirical means the bridge
leading from the world of physical effects to that of superphysical
causes. He himself tells how this longing was awakened in him by the
loss of a much-beloved brother. Before the dead body he came to the
question, which thereafter was never to leave him, whether there was a
land where the human individuality continues after it has laid aside
its bodily sheath, and how that land was to be found. Seeing that
scientific research was the instrument which modern man had forged to
penetrate through the veil of external phenomena to the causes
producing them, it was natural for Crookes to turn to it in seeking the
way from the one world into the other.

It was after meeting with a man able to produce effects within the
corporeal world by means of forces quite different from those familiar
to science, that Crookes decided to devote himself to this scientific
quest. Thus he first came into touch with that sphere of phenomena