Joly, Phil. Mag. March, 1904.

S. and P. Curie, C. R. 129, p. 823, 1899.

Giesel, Verhandlg. d. D. Phys. Ges. Jan. 5, 1900.

Salomonsen and Dreyer, C. R. 139, p. 533, 1904.

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

Becquerel, C. R. 133, p. 709, 1901.

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

Hardy, Proc. Physiolog. Soc. May 16, 1903.

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

Curie and Debierne, C. R. 132, p. 768, 1901.