Democratic Sentinel, Volume 20, Number 22, Rensselaer, Jasper County, 5 June 1896 — The Fluoroscope. [ARTICLE]

The Fluoroscope.

Mr. Thomas A. Edison has invented an apparatus, called the fluoroscope, by the aid of which a surgeon, instead of photographing with the X-rays the bones or other hard substances concealed under the skin and flesh of a patient, may actually see them. The machine depends for its action upon the fact that the X-rays possess the property of rendering luminous certain substances, which chemists call fluorescent. Mr. Edison first determined, by experiment, that the best fluorescent substance for this purpose was calcium tungstate. The tungstate is spread in a smooth layer upon a piece of pasteboard which forms the bottom of a small box, having holes for the eyes at the upper end. A Crookes tube, enclosed in another box, is excited by a current of electricity, and if the hand, for instance, is to be examined, it is placed upon the box containing the tube. The observer then looks into the viewing box, whose tungstate-covered bottom is placed directly above the hand, and sees, with startling distinctness, the bones and joints, showing as dark and delicately graduated shadows, while the flesh is only faintly visible. The reason the bones appear is because they intercept the X-rays, and thus prevent the tungstate surface from ..becoming fluorescent where their shadows fall.