He was one of the first people to create polyvinyl chloride (PVC), and, together with Carl Schotten, he discovered the Schotten-Baumann reaction.

He passed his first exam in 1870 and received his PhD in 1872 for work with Felix Hoppe-Seyler.

The same year, Emil Heinrich Du Bois-Reymond offered him a position as the Head of the Chemistry Department of the Institute of Physiology in Berlin.

In 1895, he took over the management of Hoppe-Seyler's Zeitschrift für Physiologische Chemie with Albrecht Kossel.

Together with his coworkers, he was able to prove that thyroxine was the active ingredient in the thyroid gland.