215.
If we place a black band, or stripe, on white paper,26 the violet border will spread till it meets the yellow-red edge. In this case the intermediate black is effaced (as the intermediate white was in the last experiment), and in its stead a splendid pure red will appear.27 The series of colours will now be as follows:—
Blue.
Blue-red.
Red.
Yellow-red.
Yellow.
216.
The yellow and blue, in the first case (214), can by degrees meet so fully, that the two colours blend entirely in green, and the order will then be,
Yellow-red.
Green.
Blue-red.
In the second case (215), under similar circumstances, we see only
Blue.
Red.
Yellow.