ON ACCIDENTAL OR SUBJECTIVE COLORS. 231 



correctly of the tints of dyed stuffs. He gives the reason of the fact, long and 

 generally known, that an assortment of complementary colors is never disagree- 

 able, showing from his experiments that these colors re-enforce and embellish 

 one another by proximity, whatever difference may otherwise exist between the 

 bodies placed in juxtaposition. He proves, on the other hand, tliat if the non- 

 complementary colors which approximate most to the seven primitive colors are, 

 in general, embellished by juxtaposition, they yet seem to the eye more or less 

 inappropriate ; that the greater the analogy of colors the greater is the prob- 

 ability that their mutual juxtaposition will be injurious to one of them, or even 

 to both ; that if theory cannot prescribe, for the satisfaction of the eye, the 

 arrangement of non-complementary colors in so decisive a manner as it is com- 

 petent to do with regard to complementary colors, it is because of the impossi- 

 bility of designating at present in a precise mannc r these innumerable colors of 

 bodies in default of invariable types to which they might be referred, such as 

 are, for instance, the colored rings of Newton. 



Chromatic scale of M. Nohlli. — These last expressions of M. Chevreul recall 

 to us an excellent memoir of Nobili on colors in general, and particularly on a 

 new chromatic scale. Author of metallochromy, that wonderful art by means 

 of which he. obtained on plates of steel the most brilliant colors by depositing on 

 their surface, through electro-chemical processes, thin coats of different saline 

 substances, of acetate of lead for instance, and persuaded that science never so 

 well appreciates its own interest as when it associates itself with the arts, the 

 distinguished physicist last mentioned devoted long hours to the formation of a 

 chromatic scale composed of forty-four tints, disposed according to the order of 

 the thin layers or films which form them. This assemblage produced an inde- 

 scribable effect ; it was of the same nature with that which is produced on the 

 ear by a scale of semitones executed by an exquisite vocal organ ; so great, in- 

 deed, was the pleasure of contemplating these colors which passed gradually 

 from one tone to another, that the eye could scarcely be satiated with the view 

 of so charming a spectacle. Nobili attempted to reproduce his scale in oil and 

 water-colors ; but the best executed copies gave but an imperfect idea of the 

 original colors, and since Nobili is dead, carrying with him not the secret of his 

 art but the untiring application, the incommunicable dexterity which alone can 

 with certainty produce uniformity of tints, science and art will, perhaps, have 

 long to deplore the want of a gamut of colors universally adopted. 



A singular anomaly of the chromatic scale of Nobili particularly attracted 

 attention ; the green was found far from the blue, between the red and yellow. 

 Men of art were surprised at this inversion ; when the finest green tints of the 

 gamut were submitted to them, impelled by habit, they placed them among the 

 yellows and blues of the second interval ; but, in that position they fatigued 

 the eye ; harmony was destroyed, and was not re-established except by returning 

 to the primitive order. But in what consists this harmony ? It may be felt, but 

 not defined. Its principal character in nature is the conjunction of two comple- 

 mentary colors, or colors, as we have seen, of such a nature that one gives rise 

 to the other. Venturi was right in saying : Agreeable and harmonious ahooe 

 all is the union or succession of those colors which are in correspondence icitli 

 one another, so that the sensation of one draws after it the imaginative sensation 

 of the other. In this we evidently have but one of the aspects of the harmony 

 of colors; it extends much further; but, in the present state of the science, it 

 Avould be impossible to convey complete ideas on the subject. 



Nobili concluded his long memoir with some curious and useful remarks on 

 the clearness, the strength, the beauty, the warmth and coolness, the liveliness 

 and the gravity of colors. The clearest is the yellow ; a clear tint results from 

 the mixture of little color with much white light ; a strong tint is the product of 

 much color and little white light ; orange is the brightest, yellow is monotonous ; 

 yellow and red are warm, light blue is cool; red and orange are gay, violet and 



