1857.] M. ChevreuVs Lmvs of Colour. 431 



If attention is not paid to the arrangement of colours according 

 to the above diagram, instead of their mutually improving each 

 other, they will, on the contrary, lose in beauty ; thus if blue and 

 purple are placed side by side, the blue throwing its complementary 

 colour, orange, upon the purple, will give it a faded appearance ; 

 and the blue receiving the orange yellow of the purple will assume 

 a greenish tinge. The same may be said of yellow and red, if 

 placed in juxtaposition. The red, by throwing its complementary 

 colour green, on the yellow, communicates to it a greenish tinge ; 

 the yellow, by throwing its purple hue, imparts to the red a dis- 

 agreeable purple appearance. The very great importance of these 

 principles to every one who intends to display or arrange coloured 

 goods or fabrics was convincingly shown by Mr. Grace Calvert, 

 from a great variety of embroidered silks (kindly lent by Mr. 

 Henry Houldsworth), calicos, and paper-hangings, which demon- 

 strated that if these laws are neglected, not only will the labour 

 and talent expended by the manufacturer to produce on a given 

 piece of goods the greatest effect possible, be neutralised, but per- 

 haps lost. It was clearly demonstrated that these effects are not 

 only produced by highly-coloured surfaces, but also by those whose 

 colours are exceedingly pale, as, for example, light greens, or light 

 blues with buffs, and that even in gray surfaces, as pencil drawings, 

 the contrast of tone between two shades was distinctly visible. The 

 contrast of tone or tint was most marked when two tints of the 

 same colour were juxtaposed, and it was therefore the interest of 

 an artist to pay attention to this principle when employing two 

 tints of the same scale of colour. From the "mixed contrast" 

 arises the rule that a brilliant colour should never be looked at for 

 any length of time, if its true tint or brilliancy is to be appreciated ; 

 for if a piece of red cloth is looked at for a few minutes, green, its 

 complementary colour, is generated in the eye, and adding itself to 

 a portion of the red, produces black, which tarnishes the beauty of 

 the red. This contrast explains, too, why the tone of a colour is 

 modified, either favourably or otherwise, according to the colour 

 which the eye has previously looked at. Favourably, wheli, for 

 instance, the eye first looks to a yellow surface, and then to a 

 purple one ; and unfavourably, when it looks at a blue and then at 

 a purple. 



Mr. Grace Calvert also showed that black and white surfaces 

 assume different hues according to the colours placed in juxtaposi- 

 tion with them ; for example, black acquires an orange or purple 

 tint if the colours placed beside it are blue or orange ; but these 

 effects can be overcome, in the case of these or any colours, by 

 giving to the influenced colour a tint similar to that influencing it. 

 Thus, to prevent black becoming orange by its contact with blue, 

 it is merely necessary that the black should be blued, and in such 

 proportion that the amount of blue will neutralize the orange 

 thrown on it by influence, thus producing black. As an instance, 



