[71]. Townsend, Phil. Trans. A, p. 129, 1899.
[72]. Townsend, loc. cit. p. 139.
[73]. Some difference of opinion has been expressed as to the value of V required to produce ions at each collision. Townsend considers it to be about 20 volts; Langevin 60 volts and Stark about 50 volts.
[74]. Rutherford, Phil. Mag. Jan. 1899.
[75]. Rutherford, Phil. Mag. Jan. 1899.
[76]. Strutt, Phil. Trans. A, p. 507, 1901 and Proc. Roy. Soc. p. 208, 1903.
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[78]. Eve, Phil. Mag. Dec. 1904.
[79]. Rutherford, Phil. Mag. p. 137, Jan. 1899.
[80]. Child, Phys. Rev. Vol. 12, 1901.