It was up to the Russian chemist Karl Klaus to verify their existence, which he did in 1844 by isolating measurable quantities of ruthenium.
Karl Ernst Claus (1796–1864), Russian chemist and discoverer of ruthenium
Karl Marx | Santa Claus | Ernst & Young | Max Ernst | Karl Pilkington | Karl Lagerfeld | Karl G. Heider | Karl Rove | Karl Pearson | Karl May | Karl Liebknecht | Karl Friedrich Schinkel | Karl Dönitz | Karl Jenkins | Ernst Haeckel | Karl Stefanovic | Karl Bodmer | Ernst Mayr | Ernst Jünger | Hugo Claus | Ernst Zündel | Karl Wilhelm Friedrich Schlegel | Karl Malone | Karl Wolf | Karl Valentin | Karl Popper | Karl Malden | Karl Kesel | Karl Barth | Ernst Gombrich |