He became full professor in chemistry in 1844. Ruthenium In 1840, Claus, received a substantial amount of platinum ore samples for his studies from the Ural Mountains and the St Petersburg Mint and started working on chemistry and isolation of noble metals, in particular rhodium, iridium, osmium, and to a lesser extent, palladium and platinum. In 1844, he discovered a new chemical element, which he named ruthenium, after Ruthenia, the latinised name for Russia and the Latin name of Rus', by which Сlaus meant the Russian Empire and Russia in particular. Choosing the name for the new element, he stated: "I named the new body, in honour of my Motherland, ruthenium. I had every right to call it by this name because Mr. Osann relinquished his ruthenium and the word does not yet exist in chemistry." Claus managed not only to isolate ruthenium, but also determine its atomic weight and chemical properties. He noted the similarity of the chemical properties of ruthenium, rhodium, palladium and platinum and meticulously documented his results. For this discovery, he was awarded the Demidov Prize of 5,000 rubles (which was of much financial help to his large family). He sent samples of new element for analysis to Jöns Jakob Berzelius, who was one of the most renowned scientists in the field of new elements, and thereby became known to European scientists. Health and late years Claus was known for his negligent attitude towards his health. In particular, he often tasted his chemicals and new compounds and tested the strength of the acids by dipping a finger in them and touching his tongue with it. Once he severely burned his mouth while tasting one of the new ruthenium compounds that he had synthesized. When he isolated osmium tetroxide – a rather toxic chemical – he described its taste as astringent and pepper-like. In April 1845, he was poisoned by osmium tetroxide vapors and had to stop working for two weeks. In 1852, Klaus moved from Kazan back to the University of Tartu and assumed position of professor in pharmacy. He died in Tartu in 1864. See also List of Baltic German scientists List of Russian chemists References 1796 births 1864 deaths Scientists from Tartu People from Kreis Dorpat Baltic-German people Chemists from the Russian Empire Discoverers of chemical elements 19th-century botanists from the Russian Empire University of Tartu alumni Academic staff of Kazan Federal University Demidov