POPULAR SCIENTIFIC LECTURES. 



619 



of ealors afford. Two colors may, without 

 injury, be juxtaposed, which indeed are so 

 similar as to look like varieties of the same 

 color, produced by varying degrees of light 

 and shade. Thus, upon scarlet the more 

 shaded parts appear of a carmine, or on a 

 straw-color they appear of a golden yellow. 



If we pass beyond these limits, we arrive 

 at unpleasant combinations, such as carmine 

 and orange, or orange and straw-yellow. The 

 ^distance of the colors must then be increased, 

 so as to create pleasing combinations once 

 more. The complementary colors are those 

 which are most distant from each other. 

 When these are combined, such, for instance, 

 as straw-color and ultramarine, or verdigris 

 and purple, they have something insipid but 

 crude; perhaps because we are prepared to 

 expect the second color to appear as an after- 

 image of the first, and it does not sufficiently 

 appear to be a new and independent element 

 in the compound. Hence, on the whole, 

 combinations of those pairs are most pleas- 

 ing in which the second color of the comple- 

 mentary tint is near the first, though with a 

 distinct difference. Thus, scarlet and green- 

 ish blue are complementary. The combina- 

 tion produced when the greenish blue is 

 allowed to glide either into ultramarine, or 

 yellowish green (sap green), is still more 

 pleasing. In the latter case, the combina- 

 tion tends toward yellow, and in the former, 

 toward rose-red. Still more satisfactory com- 

 'binations are those of three tints which bring 

 about equilibrium in the impression of color, 

 and, notwithstanding the great body of color, 

 avoid a one-sided fatigue of the eye, without 

 falling into the baldness of complementary 

 tints. To this belongs the combination 

 which the Venetian masters used so much 

 red, green, and violet ; as well as Paul Vero- 

 nese's purple, greenish blue, and yellow. 

 The former triad corresponds approximately 

 to the three fundamental colors, in so far as 

 these can be prodticed by pigments ; the lat- 

 ter gives <he mixtures of each pair of funda- 

 mental colors. It is however to be observed, 

 that it has not yet been possible to establish 

 rules for the harmony of colors with the same 

 precision and certainty as for the consonance 

 of tones. On the contrary, a consideration 

 of the facts shows that a number of acces- 

 sory influences come into play, when once 

 the colored surface is also to produce, either 

 wholly or in part, a representation of natural 

 objects or of solid forms, or even if it only 

 offers a resemblance with the representation 

 of a relief, of shaded and of non-shaded sur- 

 faces. It is moreover often difficult to estab- 

 lish, us a matter cf fact, what are the colors 

 which produce the harmonic impression. 

 This is pre-eminently the case with pictures 

 jn which the aerial color, the colored reflec- 

 rtion and shade, so variously alter the lint of 

 oach single colored surface when it is not 

 perfectly smooth, that it is hardly possible to 

 j give an indisputable determination of its tint. 

 In snoh cases, moreover, the direct action of 

 the color upon the eye is only a subordinate 

 means ; for, on th'e other hand, the .promi- 



nent colors and lights must also serve for 

 directing the attention to the more important 

 points of the representation. Compared with 

 these more poetical and psychological ele- 

 ments of the representation, considerations 

 as to the pleasing effect of the colors aro 

 thrown into the background. Only in the 

 pure ornamentation on carpets, draperies, 

 ribbons, or architectonic surfaces is there free 

 scope for pure pleasure in tho colors, and 

 only there can it develop itself according to 

 its own laws. 



In pictures, too, there is not, as a general 

 rule, perfect equilibrium between the various 

 colors, but one of them preponderates to an 

 extent which corresponds to the dominant 

 light. This is occasioned, in the first case, 

 by the truthful imitation of physical circum- 

 stances. If the illumination is rich in yellow 

 light, yellow colors will appear brighter and 

 more brilliant than blue ones ; for yellow 

 bodies are those which preferably reflect yel- 

 low light ; while that of blue is only feebly 

 reflected, and is mainly absorbed. Before 

 the shaded parts of bluo bodies, the yellow 

 aerial light produces its effect, and imparts 

 to the blue more or less of a gray tint. Tho 

 same thing happens in front of red and green, 

 though to a less extent, so that, in their 

 shadows, these colors merge into yellow. 

 This also is closely in accordance with the 

 aesthetic requirements of artistic unity of 

 composition in color. This is caused by the 

 fact that the divergent colors show a relation 

 to the predominant color, nnd point to it 

 most distinctly in their shades. Where this 

 is wanting, the various colors are hard and 

 crude ; and, since each ono calls attention to 

 itself, they make a motley iuid disturbing im- 

 pression ; and, on the other hand, a cold 

 one, for the appearance of a flood of light 

 thrown over the objects is wanting. 



We have a natural type of the harmony 

 which a well-executed illumination of masses 

 of air can produce in a, picture, in the light 

 of the setting sun, which throws over the 

 poorest regions a flood of light and color, and 

 harmoniously brightens them. The natural 

 reason for this increase of aerial illumination 

 lies in the fact that the lower nnd more 

 opaque layers of air aro in the direction of 

 the sun, arid therefore reflect more power- 

 fully ; while at the bnmo time the yellowish 

 rod color of the light which has passed 

 through the atmosphere becomes more dis- 

 tinct as the length of path increases which '.i 

 has to traverse, and that further, this color- 

 ation is more pronounced as the background 

 falls into shadow. 



In summing up once more thosa consider- 

 ations, we have first seen what limitations 

 are imposed on truth to nature in artistic rep- 

 resentation ; how the painter links the prin- 

 cipal means which nature furnishes of recog- 

 nizing depths in the field of view, namely 

 binocular vision, which indeed is even turn- 

 ed against him, as it shows unmistakably the 

 flatness of tho picture ; how therefore the 

 painter must carefully select, partly tho per- 



