Page:The color printer (1892).djvu/93

 It is generally believed that green is the complement of red, but this belief is mainly due to the fact that it was advocated by Chevreul, the celebrated French chemist. Maxwell and Von Bezold say that bine-green is the complement of red, while Church, Rood, and others, say green-blue is its complementary. The experiment explained on pages 23 to 26 will show that the complement of red is a color which lies about half way between green and blue, and which, for convenience, we will call sea-green, the name preferred by some writers. This color is frequently seen at night in its most brilliant state, in the show-windows of some drug stores, produced by a light shining through a glass globe filled with a solution of ammonia and sulphate of copper.

The complement of any color can be easily obtained by looking very intently at the color selected for about one minute, and then suddenly shifting the vision to a white surface, upon which will be seen a pure tint of the complement of the color just looked at. This being true, then it follows that when we place together two colors which are complementary and view them at the same time, there will be seen when the eyes are shifted to a white surface, a tint of each color transposed—that is, the complement of one color will be the actual tint of the other; for illustration the reader will turn to Fig. 239, Plate 31, which represents red and its complement sea-green. To obtain the best results in these experiments the instructions must be followed closely.

Yon will now cover Figs. 240, 241, 242, and 243 with a white sheet of paper, leaving Fig. 239 and the black dot on the right exposed. Then hold your eyes about twelve or fifteen inches above the page and look steadily (without winking, if you can) at the black dot in the center of Fig. 239 for a half minute; then instantly shift