After brief visits to the Netherlands, France and Denmark in 1786, he studied for a degree in medicine at the German University of Greifswald. Once back in Sweden he was appointed counselor and lecturer in Natural History at the museum in Linköping in 1787. He enlisted in the Swedish navy in 1796, and became a prisoner of war in the Swedish-Russian War of 1808. He then became head physician at a Russian lazaret on Suomenlinna fortress.