A phosphor is a substance that can exhibit the optical phenomenon of phosphorescence (glowing in the dark).
The chemical element Phosphorus (Greek. phosphoros, meaning "light bearer") was discovered by German alchemist Hennig Brand in 1669 through a preparation from urine. Working in Hamburg, Brand attempted to distill salts by evaporating urine, and in the process produced a white material that glowed in the dark. Since that time, the term phosphorescence has been used to describe substances that shine in the dark without burning.