In the same year, aged 26, he was called as Professor in Mineralogy and Petrology to the Politehnica University of Bucharest, Romania.
In the 1930s, he returned to Switzerland because he would have been forced to relinquish his Swiss nationality in order to remain professor at Bucharest.
He became an honorary professorial associate at the University of Bern in 1942, where he was nominated extraordinary professor.
This led to the formation of the Subcommission of the Systematics of Igneous Rocks, under the IUGS Commission on Petrology in 1970.
He began his work on igneous rocks aged over 60, pursuing it for more than 35 years until his death in October 1998.