Sir Joseph John Thomson, OM, FRS (18 December 1856 - 30 August 1940) usually known as J. J. Thomson, was a British scientist. Thomson is credited for the discovery of the electron, of isotopes, and the invention of the mass spectrometer. Wikipedia
JJ.Thomson used a similar tube design in his experiments to show the existence of the electron almost at the same time. members.chello.nl/~h.dijkstra19/page3.html
The definitive Wikipedia entry for J. J. Thomson. Wikipedia is the biggest multilingual free-content encyclopedia on the Internet. en.wikipedia.org/wiki/J%2e_J%2e_Thomson
The definitive Wikipedia entry for J. J. Thomson. Wikipedia is the biggest multilingual free-content encyclopedia on the Internet. en.wikipedia.org/wiki/J._J._Thomson