As the extremes of the simple contrast produce a beautiful and agreeable appearance by their union, so the deepened extremes on being united, will present a still more fascinating colour; indeed, it might naturally be expected that we should here find the acme of the whole phenomenon.
COMPLETENESS THE RESULT OF VARIETY.
And such is the fact, for pure red appears; a colour to which, from its excellence, we have appropriated the term "purpur."[2]
There are various modes in which pure red may appear. By bringing together the violet edge and yellow-red border in prismatic experiments, by continued augmentation in chemical operations, and by the organic contrast in physiological effects.
As a pigment it cannot be produced by intermixture or union, but only by arresting the hue in substances chemically acted on, at the high culminating point. Hence the painter is justified in assuming that there are three primitive colours from which he combines all the others. The natural philosopher, on the other hand, assumes only two elementary colours, from which he, in like manner, developes and combines the rest.