Abstract: | The radioactivity of the noble gas radon and its short-life daughter products as the essential part of natural radioactivity have gained in topically in the last years. For this reason the history of discovery of radon has been summed up. This history is one part of the early research about radioactivity. From the appearance of induced radioactivity the way leads to the discovery of thorium emanation by Rutherford and of radium emanation by Dorn. Finally, the article deals with the detection of radon in the air by Elster and Qeitel and of the radon in well water and springivaler by Thomson because only these results have opened the way for the therapeutical usage of radon. |