Ivan Puluj in the UK. While Professor Puluj's finding were essentially X-rays, he did not recognise them as such at first, although he demonstrated X-ray pictures of a hand and fingers obtained by using his tube / lamp to his students. This credit later went on to Wilhelm Conrad Röntgen. Once Roentgen visited Professor Puluj's laboratory and the latter presented one of his tubes to Roentgen. Roentgen went home and in his laboratory started to conduct experiments with Puluj's tube. Puluj also continued to do research with his X-ray tubes. On 8 February 1896, just 6 weeks after Röntgen presented his finding
Roentgen (unit) of temperature and pressure." Using 1 esu ≈ 3.33564 C and the air density of ~1.293 kg/m³ at 0 °C and 101 kPa, this converts to 2.58 × 10 C/kg, which is the modern value given by NIST. 1 × 3.33564 × 10 × 1,000,000 ÷ 1.293 = 2.58 × 10 This definition was used under different names (e, R, and German unit of radiation) for the next 20 years. In the meantime, the French Roentgen was given a different definition which amounted to 0.444 German R. In 1928, the International Congress of Radiology (ICR) defined the roentgen as "the