47.  This nomenclature has arisen from the similarity of the shape of the current-voltage curves to the magnetization curves for iron. Since, on the ionization theory, the maximum current is a result of the removal of all the ions from the gas, before recombination occurs, the terms are not very suitable. They have however now come into general use and will be retained throughout this work.

48.  J. J. Thomson, Phil. Mag. 47, p. 253, 1899; Conduction of Electricity through Gases, p. 73, 1903.

49.  Rutherford, Phil. Mag. Jan. 1899.

50.  Townsend, Phil. Mag. Feb. 1901.

51.  Rutherford, Phil. Mag. Nov. 1897, p. 144, Jan. 1899.

52.  Townsend, Phil. Trans. A, p. 157, 1899.

53.  McClung, Phil. Mag. March, 1902.

54.  Langevin, Thèse présentée à la Faculté des Sciences, p. 151, Paris, 1902.

55.  Owens, Phil. Mag. Oct. 1899.