Geissler tubeGeiss·ler tube
a glass tube having two electrodes and containing a gas which, when electrified, takes on a luminous glow of a color characteristic of the gas: used in spectroscopy, etc.
Origin of Geissler tubeafter H. Geissler (1814-79), German inventor
(plural Geissler tubes)
After Heinrich Geissler, who invented it in 1857.