| |gray. | |gray. | |gray. | ----+-------+-------+-------+-------+------+-------+-------+-------+------ V. |(¹⁄₃₂) |(¹⁄₃₆) |(¹⁄₄₀) |(³⁄₁₂₈)|(¹⁄₄₈)|(³⁄₁₆₀)|(¹⁄₅₆) |(¹⁄₆₀) |(¹⁄₆₄) |Yellow-|Yellow-|Orange-|Red- |Red- |Red- |Purple-|Blue- |Blue- |toned |orange-|toned |orange-|toned |purple-|toned |green- |toned |gray. |toned |gray. |toned |gray. |toned |gray. |toned |gray. | |gray. | |gray. | |gray. | |gray. | ----+-------+-------+-------+-------+------+-------+-------+-------+------ Should I be correct in arranging colours upon scales identical with those upon which musical notes have been arranged, and in assuming that colours have the same ratios to each other, in respect to their harmonic power upon the eye, which musical notes have in respect to their harmonic power upon the ear, the colourist may yet be enabled to impart harmonic beauty to his works with as much certainty and ease, as the musician imparts the same quality to his compositions: for the colourist has no more right to trust exclusively to his eye in the arrangement of colours, than the musician has to trust exclusively to his ear in the arrangement of sounds. We find, in comparing the dominant parts in the first and second scales of the second series, that they are equal as to light and shade, so that their relative powers of contrast depend entirely upon colour. Hence it is that red and green are the two colours, the difference between which the colour-blind are least able to appreciate. Professor George Wilson, in his excellent work, “Researches on Colour-Blindness,” mentions the case of an engraver, which proves the power of the eye in being able to appreciate these original constituents of colour, irrespective of the intermediate phenomenon of tone. This engraver, instead of expressing regret on account of his being colour-blind, observed to the professor, “My defective vision is, to a certain extent, a useful and valuable quality. Thus, an engraver has two negatives to deal with, _i.e._, white and black. Now, when I look at a picture, I see it only in white and black, or light and shade, or, as artists term it, the effect. I find at times many of my brother engravers in doubt how to translate certain colours of pictures, which to me are matters of decided certainty and ease. Thus to me it is valuable.” The colour-blind are therefore as incapable of receiving pleasure from the harmonious union of various colours, as those who, to use a common term, have no ear for music, are of being gratified by the “melody of sweet sounds.”