It was a silent gathering, and Kennedy did not attempt to relieve
the tension even by small talk as he wrapped the forearms of each
of us with cloths steeped in a solution of salt. Upon these cloths
he placed little plates of German silver to which were attached
wires which led back of a screen. At last he was ready to begin.

"The long history of science," he began as he emerged from behind
the screen, "is filled with instances of phenomena, noted at first
only for their beauty or mystery, which have been later proved to
be of great practical value to mankind. A new example is the
striking phenomenon of luminescence. Phosphorus, discovered
centuries ago, was first merely a curiosity. Now it is used for
many practical things, and one of the latest uses is as a
medicine. It is a constituent of the body, and many doctors
believe that the lack of it causes, and that its presence will
cure, many ills. But it is a virulent and toxic drug, and no
physician except one who knows his business thoroughly should
presume to handle it. Whoever made a practice of using it at the
Novella did not know his business, or he would have used it in
pills instead of in the nauseous liquid. It is not with
phosphorised ether as a medicine that we have to deal in this
case. It is with the stuff as a poison, a poison administered by a
demon."

Craig shot the word out so that it had its full effect on his
little audience. Then he paused, lowered his voice, and resumed on
a new subject.

"Up in the Washington Heights Hospital," he went on, "is an
apparatus which records the secrets of the human heart. That is no