Röntgen X-ray discovery experiment
ID: rontgen-x-ray-discovery-experiment
Wilhelm Conrad Röntgen's 1895 first communication describes an induction coil driving an evacuated gas-discharge tube, enclosed in black cardboard in darkness. A paper screen coated with barium platinocyanide showed fluorescence even with its uncoated side facing the tube, visible two metres away. The covering excluded ordinary illumination.[ref]
On a New Kind of Rays by Wilhelm Conrad Röntgen. Röntgen, On a New Kind of Rays, §§1–2; inspected reprint p. 153
He interposed materials: a thousand-page book transmitted; lead was practically opaque. A stepped stack of foil produced a photographic plate record. Different materials were not equivalent at equal density and thickness. Photographic plates checked visual observations while remaining covered against ordinary illumination.[ref]
On a New Kind of Rays by Wilhelm Conrad Röntgen. First communication, §§2–6; reprint pp. 153–154: absorption tests and photographic controls
Section 14 lists photographs of hand bones, wire on a bobbin, boxed weights, an enclosed compass, and a lead-painted door. It does not identify the hand's owner. Magnetic deflection moved the cathode ray impact point and thus the source, without bending the emerging X-rays. Their nature remained unsettled.[ref]
On a New Kind of Rays by Wilhelm Conrad Röntgen. First communication, §§11–14 and 17; reprint pp. 156–157
The observations belong to 1895; the contemporary English translation appeared in Nature on 23 January 1896.[ref]
On a New Kind of Rays by Wilhelm Conrad Röntgen. Catalogue, On a new kind of rays: notes identify the Nature translation and its publication date
The experimental logic separates production, transmission and detection. A visibly opaque covering can transmit X-rays; fluorescence then converts deposited energy into visible light. A shadow measures a difference between paths through an object, rather than a direct view of its surface. Neither a screen's brightness nor photographic darkness alone measures an absolute X-ray energy or establishes the X-ray attenuation law below. New to topics? Read the docs here!