It occurred to Röntgen that the Crookes–Hittorf tube, which had a much thicker glass wall than the Lenard tube, might also cause this fluorescent effect.
Röntgena napadlo, že Hittorf-Crookesova banka, ktorá mala oveľa hrubšie sklo ako Lenardova banka, by mohla tiež vyvolávať rovnaký efekt.