[90] Kohlrausch and Holborn, ‹loc. cit.›, p. 200. [91] Raoult, ‹Ann. de Chim. et de Phys.› (6), «2», 84 (1884). [92] The degree of ionization of mercuric chloride is based on Raoult's freezing-point measurements and is subject to revision, and the limit of the mobility of the mercuric-ion (½ Hg) is assumed to be 48, close to the values found for the ions of zinc and cadmium, elements in the same family as mercury. [93] Lehfeldt's ‹Electrochemistry›, 1904, p. 3. [94] See table, p. 56. [95] Report of the British Association for the Advancement of Science, 1886, p. 389. [96] With the aid of more elaborate apparatus rigorous demonstrations and measurements of such diffusion currents of so-called "concentration cells" are made. [97] ‹Z. phys. Chem.›, «63», 174 (1908). The work was carried out in Abegg's laboratory. [98] ‹Report of the St. Louis Congress of Arts and Sciences›, «IV», 314 (1904). [99] ‹Am. Chem. J.›, «20», «21», «23» (1898–1900). [100] Kablukoff, ‹Z. phys. Chem.›, «4», 429 (1889). [101] ‹Phil. Mag.› (5), «36», 320 (1893). [102] ‹Z. phys. Chem.›, «13», 531 (1893). [103] Walden, ‹Z. phys. Chem.›, «54», 129 (1906); McCoy, ‹J. Am. Chem. Soc.›, «30», 1074 (1908). [104] ‹Z. phys. Chem.›, «54», 229 (1906). [105] The degrees of ionization were always determined from the relation α = Λ_{‹v›} / Λ_{∞} according to the method discussed on page 50. [106] Walden, ‹loc. cit.› [107] ‹Cf.› Arrhenius, ‹Theories of Chemistry›, p. 83 (1907). [108] In hydrogen chloride, the hydrogen and the chlorine atoms may be held in the molecules H^{+}Cl^{−} by the electric attraction of a positive charge on the hydrogen, and a negative charge on the chlorine atom (see p. 43). [109] Franklin and Kraus, ‹Am. Chem. J.›, «23», 305 (1900) (Stud.) [110] It is very likely that in aqueous acids, a large proportion, at least, of the hydrogen-ion is similarly combined with water. (Lapworth, ‹J. Chem. Soc.›, (London) «93», 2187 (1908). See Chapter XII.) [111] ‹Vide› the discussion on the "Constitution of Water," ‹and the summary› by J. Walker, ‹Transactions of the Faraday Society›, «VI», 71–123 (1910). [112] ‹Proc. Am. Acad.›, 1892; Liebig's Ann. «287», 263 (1895). [113] ‹Cf.› Walden, ‹Z. phys. Chem.›, «55», 683 (1906). [p067] CHAPTER V «THE THEORY OF IONIZATION. II» IONIZATION AND OSMOTIC PRESSURE. IONIZATION AND CHEMICAL ACTIVITY