§ I. MANY experimenters have investigated the electrical properties of flames and incandescent solids. The methods usually employed have been(1) to examine the electric conductivity of different parts of the flame;2 (2) to measure the difference of potential between platinum wires in different positions in the same flame;3 (3) to find the leakage of a charged conductor when placed near, or in view of, a flame or an incandescent solid;4 (4) to observe the leakage of a conductor, raised to a red or white heat, by an electric current, and electrically charged while it is surrounded by different gases;5 and (5) to observe the production of electrification or diselectrification by a glowing wire, through which a current is passings in neighbouring insulated conductors separated from it by different gases.6
Account of experiments in Wiedemann's "Lehre von der Elektricet#228;t," vol. iv. B. Carl's Rep., xvii. pp. 269#x2013;294, 1881. J. J. Thomson, Phil. Mag., pp. 358, 441, 1890.
Hankel, Phil. Mag., p. 542, December 1851; Phil. Mag., p. 9, January 1860. Elster, and Geitel, Wied. Ann., vol. xvi., 1882; also Phil. Mag., September 1882. Maclean, and Goto, Phil. Mag., August 1890.
Guthrie, Phil. Mag., p. 308, April 1873. Giese, Wied. Ann., vol. xvii. Schuster, Lecture Royal Institution, February 22, 1895.
Guthrie, Phil. Mag., p. 237, October 1873.
Elster, and Geitel, Wied. Ann., xxxvii. p. 315, 1889; Elster, and Geitel, Wied. Ann., xxxviii. p. 27, 1889.
Kelvin, Maclean, Galt, "Electrification and Diselectrification of Air," Proceedings of the Royal Society, London, vol. lvii., February and March 1895; also B. A. Report. 1895.
Kelvin, "Electrostatics and Magnetism," #167; #167; 413 414, pp. 332, 333.