Neon
Two British scientists, Sir William Ramsay and Morris Travers, discovered neon, argon, krypton, and xenon.  Together they discovered a brand new gas element in 1898.  Four years before, Ramsay, a physical chemist, had found argon and was the first person to isolate helium in 1895.  The scientists froze argon, using liquid air, and then evaporated this to collect the gas that is produced.  Using a high voltage, they collected the first sample of the gas.  To their surprise, the gas illuminated the glass tubes and glowed with bright crimson light.