In 1867 he became privatdozent in Berlin University, and in the following year was chosen professor of physics at the Federal Polytechnic Institute in Zurich, where he was the teacher of Wilhelm Conrad Röntgen; then, after a year or two at Würzburg, he was called in 1872 to Strasbourg, where he took a great part in the organization of the new university, and was largely concerned in the erection of the Physical Institute. Finally in 1888 he went to Berlin as successor to Hermann von Helmholtz in the chair of experimental physics and directorship of the Berlin Physical Institute. He died after a protracted illness at Israelsdorf, near Lübeck, on 21 May 1894.[1]