thumb|1862 Geißler discharge tube with holder in the [[Teylers Instrument Room. In 1856, his brother Wilhelm Geissler had worked together with Van der Willigen, the future (1864) conservator of the Physical Cabinet of Teylers Museum. After that, Heinrich Geissler made his well-known glass discharge tubes in Bonn. ]]
Johann Heinrich Wilhelm Geißler (26 May 1814 in Igelshieb – 24 January 1879) was a skilled glassblower and physicist, famous for his invention of the hand pumped Geissler mercury vacuum pump in the mid-1850's and in 1857, the Geissler tube, made of glass and used as a low pressure gas-discharge tube; these two inventions were critical technologies leading to the discovery of the electron.
Geissler descended from a long line of craftsmen in the Thüringer Wald and in Bohemia.</blockquote>
The Geissler tube was used for entertainment throughout the 1800s and evolved around 1910 into commercial neon lighting. Advances in Plucker and Geissler's discharge tube technology developed into the Crookes tube, with which the electron was discovered in 1897, and in 1906 into the amplifying vacuum tube, the basis of electronics and long-distance communication technologies like radio and television.
Geissler was awarded an honorary doctorate in 1868.