about Osmium » Discoverer

Due to its high melting point, it wasn’t until the 18^th century that crude platinum was successfully melted for the first time. This was done by concentrating the sun’s light in a large concave mirror. In 1797, French chemist and politician Antoine-François de Fourcroy came very close to discovering osmium during his analyses of insoluble residues of platinum ore. This preliminary work on platinum group metals was built upon by chemist and mineralogist Smithson Tennant and by chemist and physicist William Hyde Wollaston, who later went on to become secretary of the Royal Society. Wollaston, concentrating on readily soluble platinum residues, discovered palladium and rhodium in the early 19^th century. In 1803 and 1804, concentrating on the less soluble residues, Tennant discovered iridium and osmium. It wasn’t until 1844 that German-Baltic chemist Karl Ernst Klaus discovered ruthenium.

Tennant’s experiments in 1803 began with the study of dry platinum residue. By dissolving the residues in potassium nitrate (KNO₃, the potassium salt of nitric acid) and adding water, he formed a volatile metallic oxide. Tennant eventually isolated metallic osmium from this solution of platinum residue in potassium nitrate. The metal gained its name after osme, the ancient Greek word for smell, because of the odor of its volatile oxide. In 1813, Tennant was appointed professor of chemistry at Cambridge University.