Fluorescent lamp began with the Geissler tube continued as even better vacuums were produced. The most famous was the evacuated tube used for scientific research by William Crookes. That tube was evacuated by the highly effective mercury vacuum pump created by Hermann Sprengel. Research conducted by Crookes and others ultimately led to the discovery of the electron in 1897 by J. J. Thomson and X-rays in 1895 by Wilhelm Roentgen. But the Crookes tube, as it came to be known, produced little light because the vacuum in it was too good and thus lacked the trace amounts of gas that are needed
Harley A. Wilhelm Mallinckrodt, Union Carbide and DuPont began producing uranium by the Ames process, and Ames phased out its own production by early 1945. The Ames Laboratory also produced of extremely pure cerium for the cerium sulphide crucibles used by the plutonium metallurgists. Fears that world supplies of uranium were limited led to experiments with thorium, which could be irradiated to produce fissile uranium-233. A calcium reduction process was developed for thorium, and produced some . After World War II, Spedding and Wilhelm founded the Institute of Atomic Research and the Ames Laboratory of the Atomic Energy Commission. Wilhelm became its associate