[8] Etudes sur les affinités chimiques, 1867; Ostwald's Klassiker, No. 104.
[9] Died April, 1903.
[10] For a mathematical treatment of the Phase Rule the reader is referred to the volume in this series on Thermodynamics, by F. G. Donnan.
[11] Liebig's Annalen, 1873, 170, 192; Ostwald, Lehrbuch, II. 2. 111.
[12] The action of gravity and other forces being excluded (see p. [5]).
[13] It may seem as if this were a contradiction to what was said on p. [4] as to the effect of the addition of ammonia or hydrogen chloride to the system constituted by solid ammonium chloride in contact with its products of dissociation. There is, however, no contradiction, because in the case of ammonium chloride the gaseous phase consists of ammonia and hydrogen chloride in equal proportions, and in adding ammonia or hydrogen chloride alone we are not adding the gaseous phase, but only a constituent of it. Addition of ammonia and hydrogen chloride together in the proportions in which they are combined to form ammonium chloride would cause no change in the equilibrium.
[14] The vapour pressure of water in small drops is greater than that of water in mass, and the solubility of a solid is greater when in a state of fine subdivision than when in large pieces (cf. Hulett, Zeitschr. physikal. Chem., 1901, 37. 385).
[15] See Ostwald, Lehrbuch, II. 2. 476, 934; Roozeboom, Zeitschr. physikal. Chem., 1894, 15. 150; Heterogene Gleichgewichte, I. p. 16; Wegscheider, Zeitschr. physikal. Chem., 1903, 43. 89.
[16] Ostwald, Lehrbuch, II. 2. 478.
[17] See also Hoitsema, Zeitschr. physikal. Chem. 1895, 17. 651.