| | Cancer | Radiation Treatment Who developed the x ray? The correct answer is Wilhelm Conrad Rontgen. Wilhelm Conrad Rontgen, a German physicist, discovered the X-ray on 8th November 1895. He called them “X” because of their unknown nature. Radiation Treatment - Related Articles Cures for Stomach Cramps Types of Groin-Pull Injury Treatments About Daily Living With Diabetes How to Use Progressive Bifocal Lenses Insecticide Residual Toxicity to Honey Bees About Colon Cleansing Detox Long-Term Effects of Cushings Disease If Left Untreated