The Eidgenössische Technische Hochschule Zürich (ETH Zurich) appointed him professor in 1893, where he stayed until a severe illness forced him to retire from the position in 1905.
He suffered from limited control of his right arm and severe headache for the rest of his life. Still he did research work in a private laboratory at ETH. In the last years of his life he lived at Ponte Tresa, Ticino. He died there in 1932.