26
Watts, Phil. Mag. July, 1903; August, 1904.
27
Runge, Phil. Mag. December, 1903.
28
Debierne, C. R. 129, p. 593, 1899; 130, p. 206, 1900.
29
Giesel, Ber. d. D. Chem. Ges. p. 3608, 1902; p. 342, 1903.
30
Debierne, C. R. 139, p. 538, 1904. Miss Brooks, Phil. Mag. Sept. 1904. Giesel, Phys. Zeit. 5, p. 822, 1904. Jahrbuch. d. Radioaktivität, no. 4, p. 345, 1904.