Mr Eastlake, justly judging it to be of the first importance, in whatever schemes might be entertained for the promotion of the Fine Arts, to secure to the artist the best materials, and the approved methods of the best times, and to give him as complete a knowledge of the history of the art he professes as might be obtained, undertook to search out and examine records with the greatest care, leaving as little to conjecture as possible. He could not dictate to the mind, but he might be able to put means into the hands of genius; the more perfect the instruments, the greater would be the freedom, and, what is of no small importance, the more durable would be the works. The first step in this direction was evidently towards a knowledge of what had been done, and had been universally admired and approved:—to discover first, if possible, what was the method and what were the technical means in the hands of Titian and Correggio, of Rubens and most of the Flemish painters.
Aware of the discussions and disputes concerning the invention of Van Eyck, he found it necessary to trace the progress of art from its earliest records to the date of the supposed discoverer of painting in oil—or rather discoverers, Hubert and John Van Eyck, in 1410. The conclusion to which the documentary evidence led him was this, that:—
"The technical improvements which Van Eyck introduced were unquestionably great; but the mere materials employed by him may have differed little, if at all, from those which had been long familiar. The application of oil painting to figures, and such other objects as (with rare exceptions) had before been executed only in tempera, was a consequence of an improvement in the vehicle." "It is apparent, that much has been attributed to John Van Eyck, which was really the invention of Hubert; and both may have been indebted to earlier painters for the elements of their improved process."
The very early use of oil in painting need not here be discussed, though it was necessary to go into much detail in forming a history of the art, which was the object of Mr Eastlake. Perhaps, the earliest in our practice will be found to have been in England, and may have been the legacy of art bequeathed at the departure of the Romans. It did not commence in Italy. "The use of resinous solutions combined in various proportions with oil, as a medium or vehicle for the colours, was an early technical characteristic of the northern schools, and merits attention here, accordingly."
It is the opinion of the author of "Materials for a History," &c., that the Van Eycks did not so much invent as improve; it was therefore most desirable to ascertain what was previously ready to their hands to be improved. And as to the improvement, that was perhaps really less than has been supposed, the application being the novelty. Oleo-resinous varnishes had before been in use, even from a very early period; but the admixture of these with the pigments was the great step in advance, and it may be inferred that the method of rendering these oleo-resinous vehicles colourless, or nearly so, was the great invention of John Van Eyck.
Drying oil was well known to the ancients, that is before the Christian era. "Dioscorides, whose works were familiar to medieval writers on medicine, is supposed to have lived in the age of Augustus. He mentions two drying oils; walnut-oil and poppy-oil. The principal materials employed in modern oil painting were at least ready for the artist, and waited only for a Van Eyck,—in the age of Ludius[11] and the painters of Pompeii."
We will not attempt further to pursue the history of oil painting to the time of the Van Eycks; suffice it to say, that a recipe of Theophilus, a monk of the twelfth century, furnishes materials—an oleo-resinous vehicle generally used after the time of Van Eyck—and that the improvement by Van Eyck was the substituting amber for the sandarach of Theophilus. The work of Theophilus has recently appeared, translated by Mr Hendrie from the Latin, and forms a very valuable addition to the painter's library, as well as to that of the curious and scientific, in general. The artist will find in Mr Hendrie's preface, the information he will be most desirous to possess. He strongly insists upon amber varnish as being the real vehicle or discovery of Van Eyck, and lays much stress upon a certain distilled oil as a diluent. He says:—
"Amber varnish, and probably other thick oil varnishes, would be equally benefitted, thinned with this distilled oil. It dries without a pellicle when mixed with colours. Colours used for finishing a picture, such as in the light for solid painting, or glazing for colour and shadows, are rendered very pure and without the slightest appearance of a skin, although it may be plentifully used. It dries much more slowly than any other distilled oil, and hence its great value, as it allows the artist as much time as he requires, in order to blend his colours and finish his work. In conjunction with amber varnish, it forms a vehicle which leaves nothing to be desired, and which doubtless was the vehicle of Van Eyck, and in many instances of the Venetian masters, and of Correggio; the different modes of painting necessarily producing the varied appearances of the different schools and masters."
This promises the remedy for the disease, as it were, of vehicles, the not drying from the bottom, which will delight every artist, if he finds it a practical truth. We confess, we somewhat fear the sanguine temperament of the translator of Theophilus, and should have preferred some proof to the bare assertion that the picture by John Bellini, in the National Gallery, was painted in amber varnish. Nor can we quite trust his translation of the recipe for making this amber varnish. We were startled with this account of 1 lb litharge to 1 lb linseed oil and 4 ounces of amber—is he correct in translating spigelhors litharge? It should be rosin. With regard to the value of amber varnish, Mr Eastlake quite agrees with Mr Hendrie. Another important improvement of the Van Eycks was the substitution of calcined white copperas for litharge. In a note, Mr Eastlake gives the information that on experiment it has been proved that oil does not take up any portion of the copperas, which nevertheless renders it very drying and hard, but that oil does take up sugar of lead. It should be added, however, that he does not think lead so prejudicial to colours as some have thought it to be.
The value of Mr Eastlake's book chiefly consists in the documentary evidence which is now brought to bear upon the question of vehicles; and doubtless, that which is subsequent to the time of Van Eyck is by far the most valuable. Evidence is produced not only of oils in use, and the methods of purifying them, but of varnishes, and recipes for making them, likewise of the colours used. There is yet, however, much untold with regard to the Italian practice, concerning which Mr Eastlake proposes to treat in a second volume. Yet, with regard to the Italian methods, we are not left without some important knowledge, which, however, must be considered as offered rather incidentally; for the Italians having modified, and in some respects much varied the vehicle they derived from the Flemish masters, their methods were again partially adopted by the latter; so that the methods of these two great schools of art could not be kept entirely separate.