Next to Liebig, famous professors at the university included the physician Georg Haas (who carried out the world's first human hemodialysis in Giessen in 1924), the theologian Adolf von Harnack, the lawyer Rudolf von Jhering, the economist and statistician Etienne Laspeyres, the physicist Wilhelm Conrad Röntgen, the mathematicians Moritz Pasch and Alfred Clebsch, the gestalt psychologist Kurt Koffka, the philologist and archaeologist Friedrich Gottlieb Welcker, the orientalist Eberhard Schrader, and the President of Hebrew University of Jerusalem Benjamin Mazar.