In Leipzig he became a close friend of Gustav Herglotz who was interested in partial differential equations, function theory and differential geometry, and succeeded Runge in Göttingen 10 years later.
Sa Leipzig siya ay naging isang malapit na kaibigan ng sino Gustav Herglotz ay interesado sa mga bahagi ng kaugalian equation, function teorya at kaugalian geometry, at Tagumpay Runge sa Gottingen 10 years mamaya.