Friedrich Ernst Dorn was the German physicist who discovered radon in 1900, although his discovery was nearly ignored. Dorn's announcement of his findings came upon the same time as English physicist William Ramsay revealed his the discoveries of the five other noble gases. Ramsay had already predicted the existence of radon and even specified some of its characteristics. Ramsay and his associate Whytlaw-Gray later established radon's atomic weight in a very intricate experiment. The discovery of radon was Dorn's only contribution to chemistry. Although Ramsay was awarded the Nobel Prize in Chemistry in 1904 for his work leading to the discovery of the noble gases, Dorn's achievement should not be diminished. It was unique in the history of chemistry because Dorn noted that radon develops as an emission of radium. This is the first time that one element has been shown to transmutate from another. This finding is not on...