Reviews. 167 



lins tapestry dye-works, stands in natural and pleasing association 

 with his purely chemical investigations. 



His views upon colour have heen so long and so highly appre- 

 ciated on the Continent, and especially in France, that our foreign 

 brethren have naturally wondered that we have been so tardy in 

 acknowledging their value, especially in their application to the 

 practical chromatic arts. Our natural philosophers did not over- 

 look their importance, as our university libraries can testify ; and 

 in 1848, the Cavendish Society published an admirable abstract of 

 Chevreul's views, of the existence of which the translator of the 

 work before us appears to be quite ignorant. It was not, however, 

 till the Great Exhibition in 1851, that the conspicuous superiority 

 of the French coloured designs drove our workmen to discover the 

 cause of their own inferiority, and the continual reference to Chev- 

 reul as one of the great authors of the skilful use of colours by the 

 French dyers, weavers, and other workers in the chromatic arts, 

 turned the attention of practical men in this country to his book. 

 The volume before us is the fruit of the interest thus awakened in 

 the author's researches, and we welcome its appearance in an 

 English form. 



Large as the work is, it is the demonstration of a single fertile 

 principle, which its author calls the " Law of the Simultaneous 

 Contrast of Colours." The purport of this law, is to point out 

 the singular fact, that when two coloured objects, such for example 

 as a red and a green ribbon, are placed side by side, or so near 

 each other as to be seen together, the quality and intensity of their 

 respective colours do not appear the same as when each is looked 

 at separately. Thus, the same red ribbon Avill have a different 

 tint if seen side by side with a green, with a yellow, and with a 

 blue ribbon, and these colours will in their turn be modified to the 

 eye, by their juxtaposition with red. This is the Simultaneous 

 Contrast of Colour. If, again, two shades or tints of the same 

 colour be placed together, — for example, a light red, and a dark 

 red, the latter will appear darker, and the former lighter, than 

 either does when seen alone. This is the Simultaneous Contrast of 

 Tone ; the word " tone," being used by Chevreul as synonymous 

 with intensity of tint or shade, not as referring to any real or sup- 

 posed analogy between colour and sound. 



So far as tone is concerned, the rule is sufficiently noticed above. 

 As for contrast of colour, it occurs according to the principle that 

 every colour adds its complementary to the colour it is placed 

 near or beside. Thus, red causes other colours near it to appear 

 as if its complementary green were added to them. Green tints 

 them with red. Blue adds to other colours orange. Yellow adds 

 to them purple. The appearance of any coloured body beside 

 another coloured body, is thus different from what it is when seen 

 alone or on a white ground, and the difference is such as would be 



