J 88 II- Psychical Compounds. consists in the fact that harmonious intervals have a very charac- teristic relation to the difference-tones which they give. These difference-tones coincide with certain of the primary tones or else are harmonious tones of a lower octave. For example, the difference-tones in the major cord 4, 5, 6 are i, 2, that is two tones at full octaves below the first tone of the major cord. (Prin- ciple of simplicity.) The third condition consists in the coin- cidence of the partial tones of the clang, which coincidence in- creases in degree as the harmony increases. This phonic principle, as we may call it, shows itself in the relation between tones when the tones are successive, and when the tones are simulta- neous it shows itself in the intensification of certain partial tones (difference-tones or over-tones) which are characteristic of the given intervals in any particular case. The fourth condition consists in the fact that beats of the primary tones, or beats of the over-tones and difference-tones, appear in the case of disso- nant intervals in compound clangs. (Principle of dissonant beats). References. On the Affective Results of Color Combinations: Goethe, Farbenlehre, Didakt. Teil, Pt. 6. Bruecke, Physiologie der Farben, 1866. Kirschmann and Baker, Toronto Studies, vol. 2, 1902. On Feelings of Optical Form: Fechner, Vorschule der Aesthetik (1876), vol. I, and Abhandl. der sachs. Ges. der Wiss., vol. 14. Witmer, Phil. Stud., vol. 9. Vischer, Das opti- sche Formgefuhl, 1873. Hildebrand, Das Problem der Form in der bildenden Kunst, 1893. Lipps, Raumasthetik und geome- trisch-optische Tauschungen, 1897. On Clang Harmonies: Helm- HOLTz, The Sensations of Tone, sect. 19. v. Oettingen, Harmo- niesystem in dualer Entwicklung, 1866 with supplementary treatment in Ostwald's Annalen der Naturphilosophie, vols, i — 4. Stumpf, Zeitschr. f. Psych., vol. 15. Riemann, Elemente der musikaUschen Aesthetik, 1900. Lipps, Psychol. Studien, 1885. Kruger, Archiv f. Psych,, vols, i and 2, 1903. Wundt, Grundz , 5th ed., vol. Ill, Chap. 16. § 13. EMOTIONS. . Feelings, like all psychical phenomena, are never per- manent states. In the psychological analysis of a composite feeling, therefore, we must always think of a momentary af-
