Geissler tube \Geis"sler tube`\ (Elec.)
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 {Pl["u]cker tube}, from the German physicist who
devised it.
[1913 Webster]