Jons Jacob Berzelius. Portrait of the Swedish chemist Baron Jons Jacob Berzelius (1779-1848). Berzelius was orphaned at an early age and brought up by relatives. After studying medicine he was given the chair of medicine and pharmacy in Stockholm, Sweden. He is best-known for his systematic reorganisation of 19th century chemistry. He produced the first accurate table of atomic masses for 28 elements, reintroduced initial letter symbols to label elements, came up with the concepts of isomerism and catalysis and divided chemistry into organic and inorganic branches. He also discovered the elements selenium, cerium and thorium.