Heinrich Geissler was a German physicist who is best known for his work on the design and construction of a variety of discharge tubes. He was the first to use a partially-evacuated tube to produce electrical discharge in a controlled manner, which allowed for the observation of phenomena such as electrical glow and the first investigations of the nature of cathode rays. His work laid the groundwork for the discoveries of J.J. Thomson and others on the electron and other subatomic particles.
hinrich, geisslar