Runge discovered aniline and phenol, isolated caffeine, and anticipated chromatography. He studied with Döbereiner, whose aged friend Goethe was shown by Runge how to dilate a cat’s pupils with belladonna (Runge, tagged ‘Doctor Poison’, carried his cat round to Goethe’s: the delighted Goethe gave him the coffee-beans and the challenge that started his work on caffeine). Humboldt, Gay-Lussac and Liebig were all met in Paris during a 3-year European journey undertaken after his studentship. Bunsen (first met in Berlin) and Kirchhoff became younger colleagues at the University of Breslau, now Wrocław.