e. The
rays flew through the metal and the book as if neither had been there,
and the waves of light, rolling cloud-like over the paper, showed no
change in brightness. It was a clear, material illustration of the ease
with which paper and wood are penetrated. And then I laid book and paper
down, and put my eyes against the rays. All was blackness, and I neither
saw nor felt anything. The discharge was in full force, and the rays
were flying through my head, and, for all I knew, through the side of
the box behind me. But they were invisible and impalpable. They gave no
sensation whatever. Whatever the mysterious rays may be, they are not to
be seen, and are to be judged only by their works.

I was loath to leave this historical tin box, but time pressed. I
thanked the professor, who was happy in the reality of his discovery and
the music of his sparks. Then I said: "Where did you first photograph
living bones?"

"Here," he said, leading the way into the room where the coil stood. He
pointed to a table on which was another--the latter a small
short-legged wooden one with more the shape and size of a wooden seat.
It was two feet square and painted coal black. I viewed it with
interest. I would have bought it, for the little table on which light
was first sent through the human body will some day be a great
historical curiosity; but it was not for sale. A photograph of it would
have been a consolation, but for several reasons one was not to be had
at present. However, the historical table was there, and was duly
inspected.

"How did you take the first hand photograph?" I asked.

The professor went over to a shelf by the window, where lay a number of
prepared glass plates, closely wrapped in black paper. He put a Crookes
tube underneath the table, a few inches from the under side of its top.
Then he laid his hand flat on the top of the table, and placed the glass
plate loosely on his hand.

"You ought to have your portrait painted in that attitude," I suggested.

"No, that is nonsense," said he, smiling.

"Or be photographed." This suggestion was made with a deeply hidden
purpose.

The rays from the Roentgen eyes instantly penetrated the deeply hidden
purpose. "Oh, no," said he; "I can't let you make pictures of me. I am
too busy." Clearly the professor was entirely too modest to gratify the
wishes of the curious world.

"Now, Professor," said I, "will you tell me the history of the
discovery?"

"There is no h