The chromatic diagram does not appear to be older than the last century. It is one of those happy adaptations of exacter principles to the objects of taste which might have been expected from Leonardo da Vinci. That its true principle was duly felt is abundantly evident from the works of the colourists, as well as from the general observations of early writers.67 The more practical directions occasionally to be met with in the treatises of Leon Battista Alberti, Leonardo da Vinci and others, are conformable to the same system. Some Italian works, not written by painters, which pretend to describe this harmony, are, however, very imperfect.68 A passage in Lodovico Dolce's Dialogue on Colours is perhaps the only one worth quoting. "He," says that writer, "who wishes to combine colours that are agreeable to the eye, will put grey next dusky orange; yellow-green next rose-colour; blue next orange; dark purple, black, next dark-green; white next black, and white next flesh-colour."69 The Dialogue on Painting, by the same author, has the reputation of containing some of Titian's precepts: if the above passage may be traced to the same source, it must be confessed that it is almost the only one of the kind in the treatise from which it is taken.
NOTE D.—Par. 66.
In some of these cases there can be no doubt that Goethe attributes the contrast too exclusively to the physiological cause, without making sufficient allowance for the actual difference in the colour of the lights. The purely physical nature of some coloured shadows was pointed out by Pohlmann; and Dr. Eckermann took some pains to convince Goethe of the necessity of making such a distinction. Goethe at first adhered to his extreme view, but some time afterwards confessed to Dr. Eckermann, that in the case of the blue shadows of snow (74), the reflection of the sky was undoubtedly to be taken into the account. "Both causes may, however, operate together," he observed, "and the contrast which a warm yellow light demands may heighten the effect of the blue." This was all his opponent contended.70