Sir Henry Enfield Roscoe was a British chemist. He is particularly noted for early work on vanadium, photochemical studies, and his assistance in creating Oxo (food), in its earlier liquid form.

Vanadium is a chemical element; it has symbol V and atomic number 23. It is a hard, silvery-grey, malleable transition metal. The elemental metal is rarely found in nature, but once isolated artificially, the formation of an oxide layer (passivation) somewhat stabilizes the free metal against further oxidation.