Blackwood's Edinburgh Magazine, Volume 65, No. 402, April, 1849

Mosaic painting was for some time the rival of oil-painting. It was much esteemed at Venice, where the damp affected other kinds of painting. It was introduced unquestionably by the Greeks. It afforded work for several centuries in the decoration of the church of St Mark, commencing from the eleventh century.

This department of art was not without its jealousies. The Zuccati were charged by their rivals with having filled up deficiencies in their work with other painting, and though Titian vindicated them, and is supposed to have assisted them in designs, the Venetian government decreed that they should re-execute the work at their own cost, which nevertheless was not done. Mosaic workers did not always work from the designs of others; some, and these not inconsiderable, painters applied themselves to this art. There were great "secreti" in the working in mosaic, which even now may be useful. The most important of these of working in mosaic was that of Agnolo, the son of Taddeo Gaddi, who, in 1346, repaired some of the mosaics executed by Andrea Tafi in the roof of St Giovanni at Florence. He fixed the cubes of the glass so firmly into the ground, with a stucco composed of wax and mastic melted together, that neither the roof nor the vaulting had received any injury from water from the period of its completion until the time of Vasari. May not our slate and mortar system be happily superseded? Mrs Merrifield takes occasion to redeem from his prison, to which, in her preface to the translation of Cennino Cennini, she had condemned, that earnest old man, upon the authority of the subscription from the prison of the Stinche – showing that it was the domicile of the transcriber, not the author. Vasari asserts that Cennino Cennini, to whom the secret of mosaic work was transmitted from Agnolo Gaddi, left a treatise on the subject. No such work has been yet found; but as there are other MSS. of the author, the treatise may be yet forthcoming. There is an anecdote which shows there may be better gold than comes from the mint. Alesso Baldovinetto, who spared no pains to learn the best methods of working in mosaic, learned much of the art from a German traveller to whom he had given a lodging. Thus, having been well informed, he worked with great success. At eighty years of age, feeling the natural infirmities fast approaching, he sought a retreat in the hospital of St Paul. "It is related that, in order to insure himself a better reception, he took with him to his apartments in the hospital a large chest, which was thought to contain money; and, in this belief, the officers of the hospital treated him with the greatest respect and attention. But their disappointment may be imagined, when, on opening the chest, after the decease of the aged artist, they found nothing but drawings on paper, and a small book which taught the art of making the mosaics, (Pietre del Musaico) the stucco, and the method of working. At the present time, we should have considered this little book a greater treasure than the money which was so much desired." We here have another delightful passage from Vasari, which will readily be accepted as the old man's excuse. "It was no wonder that they did not find money, for Alesso was so bountiful, that everything he possessed was as much at the service of his friends as if it had been their own." The introductory remarks on mosaic may be well worth the builder's and architect's attention, now that great improvements have been made in the making of glass, and that it is rendered so cheap; whilst duty was according to weight, the great art was to make it as thin as possible, hence the greater nicety and expense in the manufacture. To make thick, strong, or, in the language of mosaic art, cubes of glass for ornamental purposes, and as a preservative from weather, is a desideratum of the present day.

Few people will interest themselves about Tarsia work, of which Vasari speaks slightingly, that it was fittest for those persons who have more patience than skill in design. An art, however, of some antiquity may yet be very commonly seen in the inlaid work of various woods in our Tunbridge ware. Indeed, the art is even now becoming more important in its application to furniture: our fashionable tables are a kind of Tarsia work.

The history of painting on glass is extremely interesting, and has engaged the attention of many writers. France and Germany have taken the lead in this art, particularly the former; less attention has perhaps been paid to its rise in Italy than the subject deserves. The art itself is so exquisitely beautiful, and its application as a religious ornament so impressive, that we rejoice to see its revival. Mrs Merrifield enlarges much upon the subject, and very happily, though her commission to Italy did not send her to a country where the best materials may be collected. Specimens of painted glass in our own country, both as to design and colour, are so admirable – some, indeed, may vie with painting in oil of the best time, with regard to drawing and effect – that we could wish a commission to collect and publish the coloured specimens that are now unknown, excepting to the curious in the art. Glass painting had attained great perfection in France in the eleventh century. It was likewise much cultivated in our own country; the windows of Lincoln cathedral show early specimens of great beauty. Glass windows were introduced into England as early as A.D. 674, by ecclesiastics, for decoration of their churches. In private houses, glass was extremely rare in the middle ages; it was not in common use till the reign of Henry VIII. It was the custom to remove windows as furniture. Before the introduction of glass, thin parchment stretched on frames, and varnished, and not unfrequently painted, protected the interior of the houses from the weather. We have always understood that, for the great improvement in glass-painting, and that which rendered the cinque-cento style so beautiful, we are indebted to John Van Eyck: before his time every variation in colour required a separate piece. The painting on glass, as on canvass, and burning in different tints and on colours on one surface, has been generally considered the discovery of the inventor of oil-painting. Mrs Merrifield rather thinks that at least a portion of this improvement is to be ascribed to Fra Giacomo da Ulmo, who found out that a transparent yellow might be given to the glass by silver – the origin of the invention being the letting fall from his sleeve a silver button into the furnace, which being closed, and the silver fused, a yellow stain had been imparted to the glass. Pottery and glass-making are nearly allied; it would be curious, if there be a fair ground for the supposition that the manufacture of glass was brought from Tyre to Venice. "In the fourteenth century the Venetians had still a colony at Tyre." The Venetian glass, however, was deficient in transparency; hence probably the Venetian practice of using black glass, which, by juxtaposition in small pieces, would certainly tend to give the appearance of greater transparency to the coloured.

We know not if there has been any great advance in the art of gilding, from early times to the present, though that of gold-beating has been brought to far greater perfection. Gold was extensively used at a very early period in all kinds of decoration, and in the fifteenth century was lavishly employed on pictures. Seven thousand leaves of gold were used on the chapel of S. Jacopo de Pistoia. The gold, as well as some of the expensive colours, was commonly provided by the parties for whom pictures were painted. On mural paintings, leaves of tinfoil, covered with a yellow varnish, were substituted for gold. It would be curious to seek how some modern uses are indebted to the publication of old recipes. "In order to economise gold, the old masters had another invention, called 'porporino,' a composition made of quicksilver, tin, and sulphur, which produced a yellow metallic powder, that was employed instead of gold. The Bolognese MS. devotes a whole chapter to this subject. A substance of a similar nature is now in use in England, and is employed as a substitute for gold in coloured woodcuts and chromo-lithographs." Wax was used as a mordant in gilding. Its use as a vehicle in painting has been much discussed; it was known to the ancients as encaustic, and, in another form, has been strongly recommended by a modern painter of great ability, whose works are fair tests of its efficiency; and if we may believe the assertions with regard to the ancient practice of Greek and mediæval painters, there may be little reason to doubt its durability. But as it was certainly known and discarded by the old masters, even before the invention of Van Eyck in oil painting, we should reasonably conclude that it was inferior to other vehicles. There is a picture by Andrea Mantegna at Milan, painted in wax, on which Mrs Merrifield makes the following remarks: – "The picture is very perfect, the colours bright, and the touches sharp. The darks are laid on very thick, but the paint appears to have run into spots or streaks, as if it had been touched with something which had touched the surface. It is said, however, that it has never been repaired, and its authenticity is stated to be undoubted. It is evident that the wax has been used liquid, for if the colours had been fused by the application of heat, the sharpness and precision of touch for which this picture, in common with other paintings of this period, is remarkable, would have been lost and melted down. The vehicle, whatever it was, appeared to me to have been as manageable as that of Van Eyck." Mrs Merrifield refers to Mr Eastlake's Materials for the fullest account of all that pertains to wax-painting. We would refer also to his Reports of the Commission on the Fine Arts for further detail.10

After some interesting accounts of statue-painting, the propriety of which has been so ably discussed by Mr Eastlake, and a few words on implements used in painting, Mrs Merrifield treats of leather, niello, and dyeing. The first of these leads her to lament the practice of the monks "during the dark ages;" who, to the supposed loss of many classic works, found out that, according to the old proverb, there is "nothing like leather." We would recommend her to become a little more acquainted with the real history of the monks during "the dark ages," their actual habits and manners, rather than trust, as we fear has been the case, to authors who have only misrepresented them. She will find matter even as interesting as the documents discovered respecting their arts and inventions. However there may be cause for lamenting the misuse of parchments which had been written on, and their conversion into waistcoats for warriors, and sandals for monks, there was no need to fit the said sandals on "the sleek and well-fed monks;" for certainly, if they were as described, they would have worn out the fewer, as "sleek and well-fed" means but fat and lazy. It would be hard to find any now who, equally with them, were given to fasting and prayer. Indeed, the very arts which they practised, into which Mrs Merrifield has made research, should, we think, rescue them from the common ill report.

Leather was used for hangings, at first only behind the seats of the owner of the house, subsequently round the room, and stamped and gilt, and ornamented with tinfoil. We doubt if our modern papers, even the "artistic," are an improvement. The old principle in furniture was richness of effect, a depth, a home-warmth both in substance and colour; the modern inferior taste is, or has been recently, for all that is light, gaudy, and flimsy. We should not be sorry to see the revival of leather hangings, as, in point of richness and look of comfort – a great thing in a room – far superior to paper. There is perhaps no very great beauty in niello, nor much cause for regret that it has fallen into disuse; yet, unimportant as it is in itself, it is the parent of the most delightful, the most useful invention – engraving. Nigellum or niello was known to the ancients, and practised during the middle ages: it is only known now by specimens in museums. Yet we think there has been an attempt to revive it in Russia. We have seen a specimen, but it was very coarsely executed.

Dyeing appears, during the middle ages, to have been the trade of the Jews. It is not ascertained at what period it was introduced into England. It is said that, in the reign of Henry III., woollen cloth was worn white, for lack of the art of dyeing – though this is doubted, as, woad having been imported in the time of John, it might be implied that dyeing was known. Before the introduction of printing-blocks, the practice of painting linen cloth intended for wearing-apparel, with devices, flowers, and various ornaments, in imitation of embroidery, was common in England. To what great results has this little dress-vanity led! How much of our commercial prosperity has its very origin in a taste condemned by the serious as frivolous! The love of ornament is an instinct, and they are slanderers of Nature in all her works, and in man's inventive mind, who would insert it in the calendar of deadly sins. There is perhaps another love, the love of profit, of a more ambiguous character: we believe there are not a few who would have made a "drab creation" of this beautiful world, now from their cotton-printing mills sending forth, by millions upon millions of yards, this "frivolous vanity" to the ends of the earth. It may be questioned if Penn's merchandise, as the bales were unpacked, would have passed the custom-house of a white conscience. Have poor Indians been as unscrupulously corrupted as cheated?

By far the greater portion of the introduction takes up the subject of oil-painting, which was the chief object of the commission. We have already spoken of the result, as well as of the little reliance to be placed upon the experience of modern painters and restorers in the country of the old masters. They flatly contradict each other. Even as to method, did Titian paint first with cold colours? One affirms, another denies. There is much evidence that the Venetian painters were more sparing than others in the use of ultramarine. Their principal blue, it appears, was azzurro della Magna, (German blue.) The receipts for making azures are numerous. Blue is the most important of our colours; it is well, therefore, that the attention of our colour-makers should be particularly directed to it. We have often felt sure, on looking at Venetian pictures, that the blues generally were not ultramarine – the beauty of which colour, great as it is, does not bear the mixture with a body of white lead with impunity – it must be used thin. One of the artists consulted said, "The Venetians never used ultramarine, which inclined too much to the violet." Though he is wrong in "never," for there is proof to the contrary, in reference to their general practice he may be right, as also for their cause of setting it aside. The very glowing, warm, general tones of the Venetians – of Titian and Giorgione especially – required a warmer blue, if we may be allowed to apply such an epithet – for we are aware that most classifiers of colours say that it is always cold; and we remember the old controversy on the subject, which Gainsborough endeavoured not unsuccessfully to decide, by painting his now celebrated picture, called the "Blue Boy." Contrary to the opinion of many artists, we are inclined to agree with Mr Field, whose chemical knowledge and experience should have great weight, that the modern colour "Prussian blue," if well prepared, is one of much value. It is certainly the most powerful – not, however, to be recommended for the clear azure of a sky. We should be glad to know the opinion of Mr Eastlake with regard to the modern ultramarine, said to be made after an analysis of the real substance. Though it belongs not to his investigation of the old practice, a note upon the subject would be very acceptable. If our blues and our chromes are permanent colours, we have little to regret in the (supposed) loss of many used by the old masters.

It is curious that even colours were purchased of the "speziali," – the apothecaries. It is well known how much we are indebted to medical science for many of the recipes in art, including those for the purification of oils and the manufacture of varnishes. "Sig. A. told me that, when he was at Venice, he made a point of going to the Piazza San Salvatore, where Titian used to purchase his colours, to see whether there were any "speziali" there still. He found one, and inquired of him if he had any old colours, such as were used by the old painters, and he was shown an orange-coloured pigment, which resembled a colour frequently found on Venetian pictures." We have before us a document of payments so late as 1699, by which it appears that, with us also, the apothecary was the vender of painters' materials. "1699 – Rob. Bayley, apothecary – for oil, gold, and colours, £61." This was for painting a high cross. Blackness has sometimes been objected to in the colouring of the greatest of landscape painters, Gaspar Poussin. If the following statement may be relied upon, the cause of this occasional blemish, if it be one, may be conjectured. Sig. A. showed a black mirror, which he said had been used in painting by Bamboccio, (Peter Van Laer,) and that it had been "bequeathed by Bamboccio to Gaspar Poussin; by the latter to some other painter, until it ultimately came into the hands of Sig. A." In pictures of an early time the darks are thick and substantial, the lights thin. This was reversed afterwards, excepting with regard to some dark blue, and other draperies, of which examples may be seen in Correggio. There is a peculiar impasto, however, of the Bolognese school, which seems to have escaped the notice of Mr Eastlake and Mrs Merrifield: it is mostly observable in Guercino. The paint on the flesh, in heads, arms, &c., is frequently greatly raised, as if modelled. We are curious to know something respecting this method – in what way the manipulation is managed.

We cannot credit the accounts given by all whom Mrs Merrifield consulted, that it was Titian's practice to lay by his pictures, after each painting, for months, and even years. This slow process implies a forbearance which can noways be reconciled with the fervour and usual impatience of genius. Without fastening him down to so systematic a necessity, we can easily believe that his pictures were long under his hand, from the repeated glazings so remarkable in his works. Exposure to the sun and air seems to have been universal. It is well known that, a short time after painting, a portion, probably a deleterious portion, of the oil rises to the surface. The atmosphere certainly takes up this, but the exposure must be frequent, for this greasiness will return. We strongly suspect that it is this deleterious exudation which destroys the purity of colours; and would recommend, from a long experience, the washing the surface of pictures, (we have used common sand for the purpose,) as often as any greasiness returns. A time will be ascertained when none recurs; and we think the picture is then pretty secure from any farther change. In this case, a kind of abrasion does what time would in the end do; but, not waiting for time, we often varnish, and leave this deleterious part of the oil to do its mischief. Much stress has been laid on the grinding of colours. The Venetians were not very careful in this matter, excepting in their glazing colours. It is very evident that, for some purposes of effect, they purposely laid on their colours very coarsely ground, and scraped down for granulation. White lead, however, it is admitted, cannot be too finely ground, or too carefully made. It is the pigment that Titian was most solicitous about. There is a letter of his extant, in which he laments the death of the person who manufactured it for him. "The Italians, and especially the Venetians," says Mrs Merrifield, "were extremely careful in the preparation of their white lead, which was generally purified by washing." A recipe of Fra Fortunato of Rovigo, recommends the grinding it with vinegar and washing it, repeating the operation: "You will then have a white lead, which will be as excellent for miniature painting as for painting in oil." With regard to the glazings of Titian, an almost incredible story is told by an artist, Sig. E. "He says that glazings are never permanent, and that nothing can make them so; and, as a proof, he told me there were in a certain palace several pictures by Titian, which had always been covered with glasses: that he was present when the glasses were removed for the time; when, to the surprise of every one present, the glazings were found to have evaporated from the pictures, and to have adhered to the inside of the glass. I considered this incredible, and it certainly appears to require proof, although it must be recollected that Lionardo da Vinci says, 'Il verde fatto dal rame, ancorchè tal color sia messo a olio, se ne va in fumo,'" &c. If the colour evaporated from the picture, it would certainly be retained by the glass; and this artist distinctly said, that all the glazings were fixed on the inside of the glass, exactly above the painting, and that the effect of the different colours on the glass was very singular. From that time, he added, he had left off glazing his pictures. This is the more strange, because painters of the Flemish school may be said to have commenced their pictures with glazing, and to have continued it throughout; yet we never heard of such a fact, though many of their pictures have been under glass.

We have elsewhere recommended, without knowing that it was an old practice, the use of white chalk and such substances with the colours, and are therefore pleased to find the following notice, – "White chalk, marble dust, gesso, the bone of cuttle-fish, alumen, and travertine, were occasionally used in white pigments. They were frequently mixed with transparent vegetable colours, to give them body: " it might be added to give them, by a semi-transparency, and that even to colours in their own nature opaque, a luminous quality.

Does "grana in grano," the Spanish term for the scarlet pigment, show the origin of the expression, "a rogue in grain." "Pierce Plowman, whose Vision is supposed to have been written in 1350, in describing the dress of a lady richly clad, says, that her robe was of 'scarlet in grain;' that is, scarlet dyed with grana, the best and most durable red dye. The import of the words 'in grain,' was afterwards changed, and the term was applied generally to all colours with which cloths were dyed, which were considered to be permanent."

"Biadetto," the artificial carbonate of copper, is said to be the blue most resembling that found in Venetian pictures. Mrs Merrifield erroneously places coal among the black pigments. It is a brown, and we know of none so useful; it is deep, but not the hot brown, such as Vandyke brown, resembling that of Teniers: Mr Eastlake has shown that it was used by the Flemish and Dutch painters. We had long used it, before we were acquainted with so authoritative a recommendation.

We find many very useful observations on oils, as to their purification, and the methods of rendering them drying. As Mrs Merrifield offers in a note a new dryer, certainly a desideratum, we quote the passage, that trials of it may be made: —

"The most powerful of all dryers is perhaps chloride of lime in a dry state: a small quantity of this, added to clarified oil, will convert it into a solid. For this reason it must be employed very cautiously: if too much be used, it may burn the brushes, and injure the colours. It has the advantage of not darkening the oil, and its drying property appears to arise from its absorbing the watery particles of the oil. Chloride of calcium is equally efficacious as a dryer, but the small quantity of iron which it contains dissolves in the oil, and darkens it. It seems probable that, if the chloride of lime were judiciously employed, it might prove serviceable as a dryer; but as I am not aware that it has been tried as such by any person but myself, the utmost caution would be required, and some experiments would be necessary, in order to ascertain the smallest possible quantity which would answer the purpose intended."

We are surprised to find, in the Bolognese MS., olive oil mentioned as mixed with linseed oil in equal proportions, because we never yet heard of any successful experiment to render it drying. As it is the property of olive oil to turn lighter, not, as other oils, darker, a proof of successful experiment would be valuable. Pacheco mentions "salad oil" with honey, in a mixture of flour paste for grounds; but this may have been nut-oil. Besides the passages in Vasari and Lomazzo, which attribute to Lionardo the use of distilled oil, there is the recipe in the Secreti of Alessio, which is conclusive as to the fact that linseed-oil was distilled and used to dilute amber varnish. We are aware that Mr Hendrie, in his valuable translation of Theophilus, strongly insists upon the superiority of distilled over other oil, but it does not appear ever to have been in general use.