We have in this and the next paragraph the outline of Goethe's system. The examples that follow seem to establish the doctrine here laid down, but there are many cases which it appears cannot be explained on such principles: hence, philosophers generally prefer the theory of absorption, according to which it appears that certain mediums "have the property of absorbing some of the component rays of white light, while they allow the passage of others."[1]
Whether all the facts adduced by Goethe—for instance, that recorded in Par. [172], are to be explained by this doctrine, we leave to the investigators of nature to determine. Dr. Eckermann, in conversing with Goethe, thus described the two leading phenomena (156, 158) as seen by him in the Alps. "At a distance of eighteen or twenty miles at mid-day in bright sunshine, the snow appeared yellow or even reddish, while the dark parts of the mountain, free from snow, were of the most decided blue. The appearances did not surprise me, for I could have predicted that the mass of the interposed medium would give a deep yellow tone to the white snow, but I was pleased to witness the effect, since it so entirely contradicted the erroneous views of some philosophers, who assert that the air has a blue-tinging quality. The observation, said Goethe, is of importance, and contradicts the error you allude to completely."[2]
The same writer has some observations to the same effect on the colour of the Rhone at Geneva. A circumstance of an amusing nature which he relates in confirmation of Goethe's theory, deserves to be inserted. "Here (at Strasburg), passing by a shop, I saw a little glass bust of Napoleon, which, relieved as it was against the dark interior of the room, exhibited every gradation of blue, from milky light blue to deep violet. I foresaw that the bust seen from within the shop with the light behind it, would present every degree of yellow, and I could not resist walking in and addressing the owner, though perfectly unknown to me. My first glance was directed to the bust, in which, to my great joy, I saw at once the most brilliant colours of the warmer kind, from the palest yellow to dark ruby red. I eagerly asked if I might be allowed to purchase the bust; the owner replied that he had only lately brought it with him from Paris, from a similar attachment to the emperor to that which I appeared to feel, but, as my ardour seemed far to surpass his, I deserved to possess it. So invaluable did this treasure seem in my eyes, that I could not help looking at the good man with wonder as he put the bust into my hands for a few franks. I sent it, together with a curious medal which I had bought in Milan, as a present to Goethe, and when at Frankfort received the following letter from him." The letter, which Dr. Eckermann gives entire, thus concludes—"When you return to Weimar you shall see the bust in bright sunshine, and while the transparent countenance exhibits a quiet blue,[3] the thick mass of the breast and epaulettes glows with every gradation of warmth, from the most powerful ruby-red downwards; and as the granite statue of Memnon uttered harmonious sounds, so the dim glass image displays itself in the pomp of colours. The hero is victorious still in supporting the Farbenlehre."[4]
One effect of Goethe's theory has been to invite the attention of scientific men to facts and appearances which had before been unnoticed or unexplained. To the above cases may be added the very common, but very important, fact in painting, that a light warm colour, passed in a semi-transparent state over a dark one, produces a cold, bluish hue, while the operation reversed, produces extreme warmth. On the judicious application of both these effects, but especially of the latter, the richness and brilliancy of the best-coloured pictures greatly depends. The principle is to be recognised in the productions of schools apparently opposite in their methods. Thus the practice of leaving the ground, through which a light colour is apparent, as a means of ensuring warmth and depth, is very common among the Dutch and Flemish painters. The Italians, again, who preferred a solid under-painting, speak of internal light as the most fascinating quality in colour. When the ground is entirely covered by solid painting, as in the works of some colourists, the warmest tints in shadows and reflections have been found necessary to represent it. This was the practice of Rembrandt frequently, and of Reynolds universally, but the glow of their general colour is still owing to its being repeatedly or ultimately enriched on the above principle. Lastly, the works of those masters who were accustomed to paint on dark grounds are often heavy and opaque; and even where this influence of the ground was overcome, the effects of time must be constantly diminishing the warmth of their colouring as the surface becomes rubbed and the dark ground more apparent through it. The practice of painting on dark grounds was intended by the Carracci to compel the students of their school to aim at the direct imitation of the model, and to acquire the use of the brush; for the dark ground could only be overcome by very solid painting. The result answered their expectations as far as dexterity of pencil was concerned, but the method was fatal to brilliancy of colour. An intelligent writer of the seventeenth century[5] relates that Guido adopted his extremely light style from seeing the rapid change in some works of the Carracci soon after they were done. It is important, however, to remark, that Guido's remedy was external rather than internal brilliancy; and it is evident that so powerless a brightness as white paint can only acquire the splendour of light by great contrast, and, above all, by being seen through external darkness. The secret of Van Eyck and his contemporaries is always assumed to consist in the vehicle (varnish or oils) he employed; but a far more important condition of the splendour of colour in the works of those masters was the careful preservation of internal light by painting thinly, but ultimately with great force, on white grounds. In some of the early Flemish pictures in the Royal Gallery at Munich, it may be observed, that wherever an alteration was made by the painter, so that a light colour is painted over a dark one, the colour is as opaque as in any of the more modern pictures which are generally contrasted with such works. No quality in the vehicle could prevent this opacity under such circumstances; and on the other hand, provided the internal splendour is by any means preserved, the vehicle is comparatively unimportant.
It matters not (say the authorities on these points) whether the effect in question is attained by painting thinly over the ground, in the manner of the early Flemish painters and sometimes of Rubens, or by painting a solid light preparation to be afterwards toned to richness in the manner of the Venetians. Among the mechanical causes of the clearness of colours superposed on a light preparation may be mentioned that of careful grinding. All writers on art who have descended to practical details have insisted on this. From the appearance of some Venetian pictures it may be conjectured that the colours of the solid under-painting were sometimes less perfectly ground than the scumbling colours (the light having to pass through the one and to be reflected from the other). The Flemish painters appear to have used carefully-ground pigments universally. This is very evident in Flemish copies from Raphael, which, though equally impasted with the originals, are to be detected, among other indications, by the finely-ground colours employed.
[1] See "Müller's Elements of Physiology," translated from the German by William Baly, M.D. "The laws of absorption," it has been observed, "have not been studied with so much success as those of other phenomena of physical optics, but some excellent observations on the subject will be found in Herschell's Treatise on Light in the Encyclopædia Metropolitana, § III."
[2] "Eckermann's Gespräche mit Goethe," vol. ii. p. 280. Leonardo da Vinci had made precisely the same observation. "A distant mountain will appear of a more beautiful blue in proportion as it is dark in colour. The illumined air, interposed between the eye and the dark mass, being thinner towards the summit of the mountain, will exhibit the darkness as a deeper blue and vice versâ."—Trattato della Pittura, p. 143. Elsewhere—"The air which intervenes between the eye and dark mountains becomes blue; but it does not become blue in (before) the light part, and much less in (before) the portion that is covered with snow."—p. 244.
[3] This supposes either that the mass was considerably thicker, or that there was a dark ground behind the head, and a light ground behind the rest of the figure.
[4] "Eckermann's Gespräche mit Goethe," vol. ii. p. 242.