ment in which the colour is also evolved and controlled by electricity might be devised.
As a partial explanation of the great beauty of the colour obtained upon the screen, it must be remembered that all the colours visible upon it are produced by the admixture of coloured light and not of pigments. In colour-music therefore, as already pointed out, the greater the number of colours combined upon the screen the greater the tendency, roughly speaking, towards increased luminosity. This partly accounts for the extreme purity and beauty of the colour when properly combined upon the screen. Successive contrast—that is, contrasts of colours following each other, but not presented to the eye at the same moment—probably also has much to do with this exceptional beauty. Simultaneous contrast also exists when a colour-chord is broken up into its constituents by the diaphragms, or by the surface of the screen. So that in colour-music we have two kinds of contrast acting upon us, whereas in painting there is but one.
Another fact that strikes most of those who
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