"The specimens of Van Eyck, Hugo van der Goes, Memling, and others, which the Florentines had seen, may have appeared, in the eyes of some severe judges (for example, those who daily studied the frescoes of Masaccio), to indicate a certain connection between oil painting and minuteness, if not always of size, yet of style. The method, by its very finish and the possible completeness of its gradations, must have seemed well calculated to exhibit numerous objects on a small scale. That this was really the impression produced, at a later period, on one who represented the highest style of design, has been lately proved by means of an interesting document, in which the opinions of Michael Angelo on the character of Flemish pictures are recorded by a contemporary artist."[16]
121. It was not, we apprehend, the resemblance to nature, but the abstract power of color, which inflamed with admiration and jealousy the artists of Italy; it was not the delicate touch nor the precise verity of Van Eyck, but the "vivacita de' colori" (says Vasari) which at the first glance induced Antonello da Messina to "put aside every other avocation and thought, and at once set out for Flanders," assiduously to cultivate the friendship of Giovanni, presenting to him many drawings and other things, until Giovanni, finding himself already old, was content that Antonello should see the method of his coloring in oil, nor then to quit Flanders until he had "thoroughly learned that process." It was this process, separate, mysterious, and admirable, whose communication the Venetian, Domenico, thought the most acceptable kindness which could repay his hospitality; and whose solitary possession Castagno thought cheaply purchased by the guilt of the betrayer and murderer; it was in this process, the deduction of watchful intelligence, not by fortuitous discovery, that the first impulse was given to European art. Many a plank had yawned in the sun before Van Eyck's; but he alone saw through the rent, as through an opening portal, the lofty perspective of triumph widening its rapid wedge;—many a spot of opaque color had clouded the transparent amber of earlier times; but the little cloud that rose over Van Eyck's horizon was "like unto a man's hand."
What this process was, and how far it differed from preceding practice, has hardly, perhaps, been pronounced by Mr. Eastlake with sufficient distinctness. One or two conclusions which he has not marked are, we think, deducible from his evidence, In one point, and that not an unimportant one, we believe that many careful students of coloring will be disposed to differ with him: our own intermediate opinion we will therefore venture to state, though with all diffidence.
122. We must not, however, pass entirely without notice the two chapters on the preparation of oils, and on the oleo-resinous vehicles, though to the general reader the recipes contained in them are of little interest; and in the absence of all expression of opinion on the part of Mr. Eastlake as to their comparative excellence, even to the artist, their immediate utility appears somewhat doubtful. One circumstance, however, is remarkable in all, the care taken by the great painters, without exception, to avoid the yellowing of their oil. Perfect and stable clearness is the ultimate aim of all the processes described (many of them troublesome and tedious in the extreme): and the effect of the altered oil is of course most dreaded on pale and cold colors. Thus Philippe Nunez tells us how to purify linseed oil "for white and blues;" and Pacheco, "el de linaza no me quele mal: aunque ai quien diga que no a de ver el Azul ni el Blanco este Azeite."[17] De Mayerne recommends poppy oil "for painting white, blue, and similar colors, so that they shall not yellow;" and in another place, "for air-tints and blue;"—while the inclination to green is noticed as an imperfection in hempseed oil: so Vasari—speaking of linseed-oil in contemporary practice—"benchè il noce e meglio, perchè ingialla meno." The Italians generally mixed an essential oil with their delicate tints, including flesh tints (p. 431). Extraordinary methods were used by the Flemish painters to protect their blues; they were sometimes painted with size, and varnished; sometimes strewed in powder on fresh white-lead (p. 456). Leonardo gives a careful recipe for preventing the change of color in nut oil, supposing it to be owing to neglect in removing the skin of the nut. His words, given at (p. 321), are incorrectly translated: "una certa bucciolina," is not a husk or rind—but "a thin skin," meaning the white membranous covering of the nut itself, of which it is almost impossible to detach all the inner laminæ. This, "che tiene della natura del mallo," Leonardo supposes to give the expressed oil its property of forming a skin at the surface.
123. We think these passages interesting, because they are entirely opposed to the modern ideas of the desirableness of yellow lights and green blues, which have been introduced chiefly by the study of altered pictures. The anxiety of Rubens, expressed in various letters, quoted at p. 516, lest any of his whites should have become yellow, and his request that his pictures might be exposed to the sun to remedy the defect, if it occurred, are conclusive on this subject, as far as regards the feeling of the Flemish painters: we shall presently see that the coolness of their light was an essential part of their scheme of color.
The testing of the various processes given in these two chapters must be a matter of time: many of them have been superseded by recent discoveries. Copal varnish is in modern practice no inefficient substitute for amber, and we believe that most artists will agree with us in thinking that the vehicles now in use are sufficient for all purposes, if used rightly. We shall, therefore, proceed in the first place to give a rapid sketch of the entire process of the Flemish school as it is stated by Mr. Eastlake in the 11th chapter, and then examine the several steps of it one by one, with the view at once of marking what seems disputable, and of deducing from what is certain some considerations respecting the consequences of its adoption in subsequent art.
124. The ground was with all the early masters pure white, plaster of Paris, or washed chalk with size; a preparation which has been employed without change from remote antiquity—witness the Egyptian mummy-cases. Such a ground, becoming brittle with age, is evidently unsafe on canvas, unless exceedingly thin; and even on panel is liable to crack and detach itself, unless it be carefully guarded against damp. The precautions of Van Eyck against this danger, as well as against the warping of his panel, are remarkable instances of his regard to points apparently trivial:—