"What was the date?"
"The eighth of November." (1895)
"And what was the discovery?"
"I was working with a Crookes tube covered by a shield of black cardboard. A piece of barium platino-cyanide paper lay on the bench there. I had been passing a current through the tube, and I noticed a peculiar black line across the paper."
"What of that?"
"The effect was one which could only be produced, in ordinary parlance, by the passage of light. No light could come from the tube, because the shield which covered it was impervious to any light known, even that of the electric arc."
"And what did you think?"
"I did not think; I investigated. I assumed that the effect must have come from the tube, since its character indicated that it could come from nowhere else. I tested it. In a few minutes there was no doubt about it. Rays were coming from the tube which had a luminescent effect upon the paper. I tried it successfully at greater and greater distances, even at two metres. It seemed at first a new kind of invisible light. It was clearly something new, something unrecorded."
"Is it light?"
"Is it electricity?"
"Not in any known form."
"What is it?"
"I don't know."
And the discoverer of the X rays thus stated as calmly his ignorance of their essence as has everybody else who has written on the phenomena thus far.
Two Interesting articles from McClure's Magazine, Vol. 6, No. 5, April, 1896 : -> HERE
1. Page 403- THE NEW MARVEL IN PHOTOGRAPHY. By H.J.W. Dam.. A VISIT TO PROFESSOR RÖNTGEN AT HIS LABORATORY IN WÜRZBURG.
2. Page 415- THE RÖNTGEN RAYS IN AMERICA.By Cleveland Moffett.