As a young man, Bunsen met with Liebig, joined Mitscherlich on an expedition through the Eifel, and visited Runge in Berlin and Gay-Lussac in Paris. He collaborated with Roscoe for ten years, but broke off to work with the young Kirchhoff on spectroscopy (the bunsen burner was a by-product of this research). Playfair was a close colleague in Marburg then Scotland. Bunsen worked alongside Helmholtz and Kirchhoff (as did Roscoe, a friend for life) at the University of Heidelberg, making it a scientific mecca. Frankland, Tyndall, Mendeleev, Meyer, Auer von Welsbach and Kamerlingh Onnes (who discovered superconductivity) were among his students.