[211]. Giesel, Verhandlg. d. D. Phys. Ges. Jan. 5, 1900.

[212]. Salomonsen and Dreyer, C. R. 139, p. 533, 1904.

[213]. Elster and Geitel, Phys. Zeit. p. 113, No. 3, 1902.

[214]. Becquerel, C. R. 133, p. 709, 1901.

[215]. Hardy and Miss Wilcock, Proc. Roy. Soc. 72, p. 200, 1903.

[216]. Hardy, Proc. Physiolog. Soc. May 16, 1903.

[217]. Whetham, Phil. Mag. Nov. 1899; Theory of Solution, Camb. 1902, p. 396.

[218]. Curie and Debierne, C. R. 132, p. 768, 1901.

[219]. Giesel, Ber. D. d. Chem. Ges. 35, p. 3605, 1902.

[220]. Ramsay and Soddy, Proc. Roy. Soc. 72, p. 204, 1903.