D defs.my
Entry 1 sense Webster, 1913

Geissler tube

/gīs'-lẽr to͞ob/ · Geis·sler tube · IPA
01 A glass tube provided with platinum electrodes, and containing some gas under very low tension, which becomes luminous when an electrical d…
  1. 1.
    A glass tube provided with platinum electrodes, and containing some gas under very low tension, which becomes luminous when an electrical discharge is passed through it; -- so called from the name of a noted maker in germany. It is called also Plücker tube, from the German physicist who devised it.(Elec.) Also: Plücker tube