Mayer — Note on the Analysis of Contrast- Colors. 39 



in certain cases, a means of analyzing a composite contrast- 

 color. Suppose that a small gray disc, or ring, when placed 

 on a colored ground gives a contrast-color which is composite, 

 like purple, and that the same depth of gray gives the maxi- 

 mum contrast-color effect for each component color of the 

 purple ; then, as we view in succession the gray discs of a 

 graded series, the contrast-color of these discs should merely 

 become darker and darker, as each component of the contrast- 

 color is similarly affected as we view darker and darker grays. 

 This, to my vision, is the case when the graded gray discs are 

 viewed on a pure green ground. But if the maximum con- 

 trast-color effect for one of the component colors is given by a 

 gray differing much in depth from the gray giving the maxi- 

 mum contrast-color effect for the other component, then the 

 contrast-color should change both in its darkness and in its hue 

 as we view in succession the darker and darker grays on the 

 colored ground. This is what takes place in the case of view- 

 ing the graded series of gray discs on a violet ground ; where 

 the greenish-yellow given by the lighter shades of gray, 

 become yellowish-green on viewing discs of deeper gray ; the 

 yellow component diminishing and the green component 

 increasing till we reach a gray containing 80 per cent of black. 



The experiments on which the foregoing statements are 

 founded were made as follows : A series of grays were selected 

 varying in depth from No. 1, containing 25 per cent of black 

 to No. 15, containing 95 per cent of black. From these gray 

 papers were cut discs of l cm in diameter which were pasted in 

 order, from 1 to 15, on seven different colored surfaces. These 

 discs were viewed, in succession, through a reflecting glass tube, 

 having an interior diameter of l'9 cm and a length of 15*5 cm . 

 This tube is coated on its outside surface with black Japan- 

 varnish, which coating does away with the reflection from the 

 outside surface of the tube and leaves alone the brilliant reflec- 

 tion from the interior surface. If a gray disc is placed on a 

 colored ground and viewed through this tube it appears sur- 

 rounded by two contrast-color rings produced by the reflection 

 of the gray disc from the interior surface of the tube. These 

 rings appear to have about double the saturation and brilliancy 

 of color of the gray disc as seen without the aid of the reflect- 

 ing tube. 



Viewing the fifteen gray discs on a green ground* the con- 

 trast color given to the discs is purple, or a mixture of red 

 and violet-blue. As you view, in order of their number, the 



* The colored grounds used in these experiments were the colored papers of 

 Milton Bradley Co., Springfield, Mass. 



