Q. If we look at the sun for a few moments, every thing seems tinged with a violet colour,—Why is this?
A. Because violet is the “accidental colour” of yellow light; and as the sun is yellow, we shall see its “accidental colour” blue, when we turn from gazing at it.
Q. Does not the dark shadow (which seems to hang over every thing after we turn from looking at the sun) arise from our eyes being dazzled?
A. Partly so: the pupil of the eye is very much contracted by the brilliant light of the sun, and does not adjust itself immediately to the feebler light of terrestrial objects; but, independent of this, the “accidental colour” of the sun being dark violet, would tend to throw a shadow upon all things. (See p. [366].)
Q. Why is black glass for spectacles the best for wear?
A. Because white is the accidental colour of black; and if we wear black glasses, every thing will appear in white light, when we take them off.
Q. Why does every thing seem shadowed with a black mist, when we take off our common spectacles?
A. Because the glasses are white, and black being its “accidental colour,” every thing appears in a black shade, when we lay our glasses down.
The accidental colour of red is bluish green.
The accidental colour of orange is blue.
The accidental colour of violet is yellow.
The accidental colour of of black is white.
And the converse of this is true:—