1. By Prof. E Goldstein. A paper read before Section A of the British Association at the Australian meeting, and ordred by the General Committee of the Association to be printed in extenso.
2. E. Goldstein, Wiedem. Ann., liv., 371; lx., 149 Phys. Zeitschr., iii., 149; Sitzungsber. Ber. Akad. d. Wiss., 1901, 222.
3. E. Wiedemann and G. C. Schmidt, Wiedem. Ann., liv., 618.
4. F. Giesel, Ber: D. Chem. Ges., XXX., 156.
5. J. Elster and H. Geitel, Wiedem. Ann., lix., 487.