[Footnote: Any parallel between colour and music can only be relative. Just as a violin can give various shades of tone,--so yellow has shades, which can be expressed by various instruments. But in making such parallels, I am assuming in each case a pure tone of colour or sound, unvaried by vibration or dampers, etc.] Yellow is the typically earthly colour. It can never have profound meaning. An intermixture of blue makes it a sickly colour. It may be paralleled in human nature, with madness, not with melancholy or hypochondriacal mania, but rather with violent raving lunacy. The power of profound meaning is found in blue, and first in its physical movements (1) of retreat from the spectator, (2) of turning in upon its own centre. The inclination of blue to depth is so strong that its inner appeal is stronger when its shade is deeper. Blue is the typical heavenly colour. [Footnote: ...The halos are golden for emperors and prophets (i.e. for mortals), and sky-blue for symbolic figures (i.e. spiritual beings); (Kondakoff, Histoire de l'An Byzantine consideree principalement dans les miniatures, vol. ii, p. 382, Paris, 1886-91).] The ultimate feeling it creates is one of rest. [Footnote: Supernatural rest, not the earthly contentment of green. The way to the supernatural lies through the natural. And we mortals passing from the earthly yellow to the heavenly blue must pass through green.] When it sinks almost to black, it echoes a grief that is hardly human. [Footnote: As an echo of grief violet stand to blue as does green in its production of rest.] When it rises towards white, a movement little suited to it, its appeal to men grows weaker and more distant. In music a light blue is like a flute, a darker blue a cello; a still darker a thunderous double bass; and the darkest blue of all-an organ. A well-balanced mixture of blue and yellow produces green. The horizontal movement ceases; likewise that from and towards the centre. The effect on the soul through the eye is therefore motionless. This is a fact recognized not only by opticians but by the world. Green is the most restful colour that exists. On exhausted men this restfulness has a beneficial effect, but after a time it becomes wearisome. Pictures painted in shades of green are passive and tend to be wearisome; this contrasts with the active warmth of yellow or the active coolness of blue. In the hierarchy of colours green is the "bourgeoisie"-self-satisfied, immovable, narrow. It is the colour of summer, the period when nature is resting from the storms of winter and the productive energy of spring (cf. Fig. 2). Any preponderance in green of yellow or blue introduces a corresponding activity and changes the inner appeal. The green keeps its characteristic equanimity and restfulness, the former increasing with the inclination to lightness, the latter with the inclination to depth. In music the absolute green is represented by the placid, middle notes of a violin.