1. Michael Faraday, Experimental Researches in Electricity, London, 1849: 2d ed.. vol. 1. pp. 490ff.
2. (a) J. J. Thomson, Conduction of Electriciry Through Gases, Cambridge: Cambridge University Press, 1903, pp. 493-494, 501.
3. (b) William Crookes, "On repulsion resulting from radiation," Phil. Trans. 170: 87-134, 1879.
4. Otto Glasser, (a) Wilhelm Conrad Röntgen und die Geschichte der Röntgenstrahlen, Berlin: Springer, 1931; (b) Wilhelm Conrad Röntgen and the Early History of Rontgen Rays, Springfield, Ill.: C. C. Thomas, 1934.
5. W. C. Röntgen, “Ueber eine neue Art von Strahlen,” Sitzber. physikalisch-medicin. Ges. Warzburg 137: 132–141, 1895. Transl. in Ref. 5b, pp. 41–52, and A. J. Bruwer, Ed., Classic Descriptions in Diagnostic Roentgenology, Springfield, Ill.: C. C. Thomas, 1964, vol. 1, pp. 25–31. (This work is an excellent source for the history of the diagnostic use of x rays, with many original contributions cited in full.)