Haber then sought an academic appointment, first working as an independent assistant to Ludwig Knorr at the University of Jena between 1892 and 1894. During his time in Jena, Haber converted from Judaism to Lutheranism, possibly in an attempt to improve his chances of getting a better academic or military position. Knorr recommended Haber to Carl Engler, a chemistry professor at the University of Karlsruhe who was intensely interested in the chemical technology of dye and the dye industry, and the study of synthetic materials for textiles. Engler referred Haber to a colleague in Karlsruhe, Hans Bunte, who made Haber an "Assistent" in 1894.