Career
Starting about 1840, Weltzien constructed new laboratories for chemistry research and teaching at Karlsruhe. Weltzien"s successor as Professor of Chemistry was Lothar Meyer. Weltzien is perhaps best known today as one of three organizers of the Karlsruhe Congress of 1860, an early international meeting of chemists, the other organizers being Wurtz and Kekulé.
Weltzien acted as the local organizer, opened the meeting with a brief welcoming speech, and chaired the first session.