[34] Wied. Ann. 24, p. 119.
[35] Wied. Beiblätter, 8, p. 869.
[36] Comptes rendus, 108, p. 510.
[37] Phil. Trans. 182, A. p. 371, 1892; Physical Optics, p. 393.
[38] Wied. Ann. 46, p. 71; 47, p. 345; 48, p. 740; 50, p. 722.
[39] Wied. Ann. 46, p. 353; 48, p. 122; 49, p. 690.
[40] Recent Researches, p. 489 et seq.
[41] Phil. Trans., A. 1897, p. 89.
[42] Brit. Assoc. Report, 1893.
[43] Comptes rendus, 127, p. 548.