2Phil. Mag. February, 1904.CHAPTER X. TRANSFORMATION PRODUCTS OF URANIUM, THORIUM, AND ACTINIUM.1Soddy, Trans. Chem. Soc. 81, p. 460, 1902.2Rutherford and Grier, Phil. Mag. Sept. 1902.3Becquerel, C. R. 131, p. 137, 1900.4Meyer and Schweidler, Wien Ber. Dec. 1, 1904.5Meyer and Schweidler, Wien Ber. 113, July, 1904.6Rutherford, Phil. Trans. A. 204, pp. 169–219, 1904.