we have to choose amongst the theories of size or egg tempera, | bringing forward of the picture from a simple outline of extreme wax tempera (emulsion), and the lime painting in "fresco secco "This outline is never lost; its beautifully opposed and beauty. harmonizing lines and masses are retained to the end, even strengthdescribed by Theophilus. When we come to the panel painting ened and accentuated, giving great distinctness at a distance, even from the 12th to the 15th century we are on surer ground. For when not actually visible. A perfectly modulated monochrome the north we have the technical directions of Theophilus, for the of light and shade fills the outline, apparent through the overlaid south those of Cennino. Theophilus (i. ch. xxvii.) prescribes a glory of colour, over which again is thrown a veil of atmosphere, a refulgence of light, a suggestion of palpitating space" (Mrs tempera of gum from the cherry tree, and, with some pigments, Herringham's Cennino, p. 218). A difficulty in the technique is white of egg. The finished panel was to be covered with an cil the rapid drying of the medium, that prevents the fusing of the varnish (vernition). Cennino prescribes a tempera of the yolk colours together in the impasto, which is possible in oil painting. of egg alone, half and half with the pigments, which have been Woltmann (History of Painting, Eng. trans. i. 406) thought that finely ground in water and are very liquid, so that there might in the north honey was mixed with the white of egg or size to prevent too rapid drying, and he wrote, "this method rendered be in the ultimate compound about as much water as egg. A possible a liquid and softly gradated handling, and though the tempera of the whole egg with the milk of fig-shoots he recom- Italian variety of tempera allowed greater depth in the shadows, mends, not for panels, but for retouching fresco-work on the wall owing to the rapid drying of the egg-yolk, modelling was often the northern gave on the whole greater brightness." In Italy, when it is dry. Tempera panels painted with egg yolk are, like secured by hatching, which is not so pleasing in its effect as the the gum tempera panels of Theophilus, to be varnished with other method of superimposing thin coats of paint one over the vernice liquida (oil varnish). In these media were executed other till the proper effect of shading is secured. One notable all the fine tempera panels of the early Italian and early German quality of tempera is its transparency, which is referred to by schools of the 15th century, and these represent a limited, but Cennino when he says that the original under-painting of terra verte is never to be wholly obliterated. within its bounds a very perfect and interesting, form of the painter's art.

A word or two may be said here about the various subsidiary processes connected with 14th and 15th century panel painting, which are of great interest as showing the conscientious, and indeed devotional spirit in which the operations were carried out. At the outset of his Traitato Cennino gives a list of the processes the panel painter has to go through, and in subsequent chapters he describes minutely each of these. The artist must "know how to grind colours, to use glue, to fasten the linen on the panel, to prime with gesso, to scrape and smooth the gesso, to make reliefs in gesso, to put on bole, to gild, to burnish, to mix temperas, to lay on grounding colours, to transfer by pouncing through pricked lines, to sharpen lines with the stylus, to indent with little patterns, to carve, to colour, to ornament the panel, and finally to varnish it." The preliminary operations, before the artificer actually begins to colour or paint, will take him six years to learn, and it requires with Cenning half a hundred chapters to describe them. The wooden panel is carefully compacted and linen is glued down over its face, and over this is laid, in many successive coats, a gesso ground of slaked plaster of Paris mixed with size, with which composition raised ornaments, such as the nimbi of saints, &c., can be modelled. Both these and the flat parts of the panel are scraped and smoothed till they are like ivory. The design of the picture is then drawn out on the panel, and the outlines sharpened up with the utmost precision. The gilding of the background and of the carved woodwork in which the panel is set now follows. Armenian bole, ground finely with white of egg diluted with water, is spread over the gesso and carefully burnished as a ground for water gilding with white of egg. The gold is then burnished till it appears almost dark (in the shadow) from its own refulgence. The delicate indented patterns which are so charming on the gilded grounds of the painted panels on East Anglian screens, such as that at Southwold, are stamped with little punches, and Cennino says this is one of the most beautiful parts of the art. In the actual painting, which is on the non-gilded part of the panel, the utmost attention is paid to the ornamentation of brocaded draperies, in which gold is used as a ground and is made to show in parts, while glazes of pigment mixed with drying oil are also used. Directions for painting the flesh, which is to be done after the draperies and background, are precise. There is an under-painting in a monochrome of terra verte and white, and over this in successive coats of great thinness the flesh-tints are spread, every tint being laid in its right position on the face, the darkest flesh-tint being shaded down to the terra verte and softened off in a tender sfumato manner. Many coats are superimposed, but the green ground is still to remain slightly visible. At the last the lightest flesh-tint is used to obtain the reliefs and the high lights are touched in in white. The outlines are sharpened up with red mixed with black. The varnishing process should be delayed for at least a year, and the varnish, which was evidently thick, is to be spread by the fingers over the painted surfaces, care being taken not to let the varnish go over the gold ground. This should be done if possible in the sun, but Cennino says that if the varnish be boiled it will dry without being placed in the sun.

The process thus described is not what we should call, in the modern sense, painting, for the precision and conventionality of the work and the great importance given to subsidiary details are quite opposed to the spirit of the art since the 16th century. Nevertheless, the naïve simplicity of the design and the exquisite delicacy of the finish have an unfailing charm. We feel, as Cennino says, that the artist has loved and delighted in his work, and regarded his patient manipulation as a religious act. A modern artist in tempera specially praises the old work for its "breadth, transparency and purity of colour," qualities "owing to the gradual

The well-known group of the "Three Graces," from Botticelli's large panel of the " Allegory of Spring," at Florence, gives the quality of tempera painting very aptly (see fig. 36, Plate X.). There is a Society of Painters in Tempera in London, and some artists are enthusiastic in their admiration of the process for its purity, sincerity and permanence.

Under the heading "tempera should be noticed another style of painting with a water-medium that is executed as a rule on a large scale and in a comparatively slight fashion. Painting for the purposes of temporary decoration on canvas or wood, so much used in the Italian cities of the Renaissance period, is of this kind. Large cartoons in colour for mural pictures or tapestry, of which Raphael's cartoons are the most famous examples, are other examples; while in modern times the technique is chiefly employed in theatrical scene painting. The pigments are tempered with size or gum, and body is given to them by whitening, pipe-clay or similar substance. Work executed in this medium dries much lighter than when it is put on, and to execute it effectively, as in the case of stage scenery, requires much skill and practice. the study of the art of distemper painting a source of considerable embarrassment to the inexperienced eye is that the colours when wet present such a different appearance to what they do when dry." So writes F. Lloyds, but W. Telbin, though he recognizes this difficulty, extols the process. A splendid material dis temper! For atmosphere unequalled, and for strength as powerful as oil, in half an hour you can do with it that which in water or oil would take one or two days!" The English word distemper" and the French " gouache are commonly applied to this style of broad summary painting in body-colour. Distemper" to English ears suggests house-decoration, "tempera "the work of the artist.

"In

844. Oil Painting.-(See Eastlake, Materials for a History of Oil Painting (London, 1847); Mérimée, De la peinture à l'huile (Paris, 1830); Berger, Beiträge zur Entwicklungs-Geschichte der Maltechnik, esp. iii. 221 sqq., and iv. (Munich, 1897), &c.; Dalbon, Les Origines de la peinture à l'huile (Paris, 1904); Ludwig, Über die Grundsätze der Oelmalerei (Leipzig, 1876); Lessing, Über das Alter der Oelmalerei, 1774.)

Oil painting is an art rather of the north than of the south and east, for its, development was undoubtedly furthered by the demand for moisture-resisting media in comparatively damp climates, and, moreover, the drying oils on which the technique depends were but sparingly prepared in lands where olive oil, which does not dry, was a staple product.

Certain vegetable oils dry naturally in the air by a process of oxydization, and this drying or hardening is not accompanied by any considerable shrinking, nor by any change of colour; so that oil and substances mixed with it do not alter in volume nor in appearance as a consequence of the drying process. There may be a slow subsequent alteration in the direction of darkening or becoming more yellow; but this is another matter. Among these oils the most important is linseed oil extracted from the seeds of the flax plant, poppy oil from the seeds of the opium poppy, and nut oil from the kernels of the common walnut. With these oils, generally linseed, ordinary tube colours used by painters in oil are prepared, and oil varnishes, also used by artists, are made by dissolving in them certain resins. Their natural drying qualities can be greatly aided by subjecting them to heat, and

If such then be the early history of oil painting, what attitude are we to adopt in face of the famous statement by Vasari that the technique was the invention of the Flemish painter Van Eyck in the year 1410? The statement was first made in the 21st chapter of Vasari's Introduction to his Lives of the Artists (1550), and runs as follows: " Fu una bellissima inventione, ed un gran' commodità all' arte della pittura, il trovare il colorito a olio. Di che fu primo inventore in Fiandra Giovanni da Bruggia (Jan van Eyck). In the life of Antonello da Messina, in the same edition, Vasari dresses up the bare fact he here relates, and gives it the personal anecdotal turn that accords with his literary methods. Here the "invention " follows on the incident of the splitting of a tempera panel varnished in oil, that according to traditional practice Van Eyck had put out in the sun to dry. This artist then turned his attention to devising some means for avoiding such mischances for the future, and, in Vasari's words, being not less dissatisfied with the varnish than with the process of tempera painting, he began to devise means for preparing a kind of varnish which should dry in the shade, so as to avoid having to place his pictures in the sun. Having made experiments with many things both pure and mixed together, he at last found that linseed and nut oil, among the many which he had tested, were more drying than all the rest. These, therefore, boiled with other mixtures of his, made him the varnish which he had long desired." This varnish Vasari goes on to say he mixed with the colours and found that it "lit up the colours so powerfully that it gave a gloss of itself," without any after-coat of varnish.

Filarete, who wrote a long treatise on architecture and the arts | St Michael at Plea, Norwich, were in oil, but this cannot be of design about 1464. It is published in the Vienna Quellen- regarded as established. schriften, neue Folge, No. III. Like Cennino, Filarete (loc. cit. p. .41) speaks of oil painting as specially practised in " Germany," and says it is a fine art when anyone knows how to compass it. The medium is oil of linseed. "But is not this very thick?" | he imagines some one objecting. 'Yes, but there is a way of thinning it; I do not quite know how; but it will be stood out in a vessel and clarify itself. I understand however that there is a quicker way of managing this-but let this pass, and let us go on to the method of painting." Filarete's evident uncertainty about a process, which may be that of the Strassburg MS. for producing olcum preciosum, and his reference to "Germany," inclines us to look elsewhere than to Italy for knowledge about the oil technique. As a fact the evidence of the recipe books is borne out remarkably by that of other records which show that a great deal of oil painting of one kind or another went on in northern lands from the 13th century onwards. These records are partly in the form of accounts, showing large quantities of oil and resins furnished for the use of painters engaged in extensive works of decoration; and partly in the form of contracts for executing pictures "in good oil colours." It is true that oil might be merely employed in mordants for gilding or in varnishes, and for oil painting merely in house-decorator fashion over wood, or for colouring statues and reliefs in stone; nevertheless, with a use of proper critical methods, it has been possible for M. Dalbon and others to establish incontestably the employment in artistic wall and panel-painting of drying oils and varnishes before the 15th century, both north and, to a lesser extent, south of the Alps. These passages have been too often quoted to be cited here. (See Eastlake, Materials, p. 46 seq.; Berger, Beiträge iii. 206 seq., &c.) The earliest of the accounts, an English one, is dated 1239: "The king (Henry III.) to his treasurer and chamberlains. Pay from our treasury to Odo the goldsmith and Edward his son one hundred and seventeen shillings and tenpence for oil, sandarac resin, and colours bought, and for pictures executed in the Queen's Chamber at Westminster." Another, about 1275 (temp. Edward I.) runs: "To Robert King, for one cartload of charcoal for drying the painting in the King's Chamber, IIIS VIIId." In Flanders in 1304 there is an account (Dalbon, p. 43): “ Pour 10 los d'oile acatée pour faire destrempe as couleurs," in 1373-1374 one for XIII libvres d'olle de linnis à faire couleurs" (p. 45). This was for the use of a certain painter Loys, who executed mural compositions of which some of the subjects are recorded. In the matter of contracts, Dalbon (p. 52) prints one of 1320 prescribing figure and landscape subjects, to be executed "en la meilleur manière que il pourront estre faites en painture," and concluding, "el seront toutes ces choses faites à huille," and he points convincingly to such wording as a proof that the work here under consideration must be regarded as artistic figure-painting and not mere house decoration. Lastly, just before 1400, the painter Jehan Malouel receives in 1399 oil with colours for "la peinture de plusieurs tables et tableaux d'autel," for the Carthusian convent of Champmol near Dijon, which proves the use of oil for panel as well as for mural painting.

The further question about the survival of actual remains of work of the class just noticed is a very difficult one. There seems no reason why all this mural and panel work in oil of the 14th century should have perished, unless the medium was faulty, and, as is natural, many attempts have been made to identify extant examples as representing these early phases of the oil technique. Mural work we need not perhaps expect to find, for we know from the later experience of the Italians of the 16th century that it was difficult even then to find a safe method for oil painting on plaster. With panels preservation would be more likely, and it is always possible that some datable work of the kind may be identified that will carry the monumental history of oil painting back into the 14th century. An exhibition of early English painted panels was held in 1896 in the rooms of the Society of Antiquaries of London, and some good judges believed at the time that certain 14th-century panels from

Such is the famous passage in Vasari that has probably given rise to more controversy than any similar statement in the literature of the arts. The question is, in what did the "invention " of the Van Eycks, Hubert and Jan his younger brother, consist? and the first answer that would occur to anyone knowing alike the earlier history of the oil medium and Vasari's anecdotal predilections is the answer "There was no invention at all.” The drying properties of linseed and nut oil and the way to increase these had long been known, as had also the preparation of sandarac oil-varnish, as well as a colourless (spirit?) varnish of which there is mention in accounts prior to the 15th century (Dalbon, p. 93). The mixing of varnish with oil for a medium was also known, and indeed the oleum preciosum may be the real "invention" of which Alberti and Filarete had only vaguely heard, and of which the Van Eycks later on received the credit. The epitaphs for the tombs of the two Van Eycks make no mention of such a feat as Vasari ascribes to them, and it is quite open to anyone to take up the position that it was no improvement in technique that brought to the Van Eycks their fame in connexion with oil painting, but rather an artistic improvement that consisted in using a traditional process to execute pictures which in design, finish, beauty and glow of coleur far surpassed everything previously produced in the northern schools. Pliny writes of the works of a Greek painter of about 400 B.C. that they were the first that had the power to rivet the gaze of the spectator," and in like manner we may say of the " Adoration of the Lamb" by the Van Eycks, the titular firstfruits of the oil painter's technique, that it impressed the world of its time so mightily through its artistic power and beauty as to elevate to a sort of mystic importance the very method in which the paints were mixed. There is much force in this view, but at the same time it is impossible to deny to the Van Eycks the credit of technical improvements. For one thing, an artist who has an exceptional feeling for colour, texture and delicacy of finish will certainly pay special attention to his technical media; for another, the Van Eycks had a reputation long before Vasari's time for researches into these media. In 1456, fifteen years after the death of the younger brother, Bartolommeo Facio, of Spezzia, wrote a tract De viris illustribus in which he speaks of a certain "Joannus Gallicus," who can be identified as Jan van Eyck, as specially "learned in those arts which contributed to the making of a picture, and was on that account credited

with the discovery of many things in the properties of colours, which he had learned from ancient traditions recorded by Pliny and other writers." Filarete (c. 1464) also knew of the repute of Jan van Eyck in connexion with the oil technique. Hence we inay credit the Van Eycks with certain technical improvements on traditional practices and preparations in the oil technique, though these can hardly be termed "inventions," while their artistic achievement was great enough to force into prominence whatever in the technical department they had accomplished. Another and a more important question remains behind: What was, in fact, the practice in the matter of oil painting in vogue before the Van Eycks, altered or at any rate perfected by them and their successors, and in general use up to the time of Vasari; and how was it related to the older more widely diffused painting " a tempera"?

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expressing exactly the same artistic ideals and dominated by the same view of the relation of art to nature. To Vasari the artistic advantage of the oil medium was, first, its convenience, and, next, the depth and brilliancy it lent to the colours, which he says it "kindled," while at the same time it lent itself to a soft fusing of tints in manipulation, so that artists could give to their figures in this technique the greatest charm and beauty combined with a force that made them seem to stand out in relief from the panel. Such a description applies very justly to work like that of the | Van Eycks in the "Adoration of the Lamb," or the later panels of Antonello da Messina, who, according to Vasari's oftenrepeated story, introduced the Flemish system of oil-painting into Venice. The description does not however apply to the freer, more sweeping, more passionate handling of the brush by the greatest of the Venetians such as Titian or Veronese, and still It is indisputable that the oil painting of the Van Eycks and less to the oil painting of 17th-century masters like Rubens or the early Flemish school, together with that of the Florentines Rembrandt or Velazquez. It is quite clear that whatever and Umbrians, and indeed of all the Italians up to Vasari's improvements in oil technique were due to the early Flemings,. time, save the Venetians, Correggio, and some other north oil painting in the modern sense owes still more to the Venetians, Italians, does not greatly differ in artistic effect, nor, as far as can who first taught the world the full artistic possibilities of the be judged, in handling, from earlier or contemporary temperas. process. Giovanni Bellini, whose noble altarpiece in S. Pietro For example, at Venice in the 15th century, Crivelli paints at Murano may be called, in a phrase once applied to another of always in tempera, Cima in oils, but the character of their surface his pictures, "the canon of Venetian art," is probably entitled is almost the same, and if anything the tempera is richer in effect to be called the father of modern oil painting. Beginning as a than the oil. The contrary is no doubt the case with the tempera painter in tempera and adopting the new process about 1475, "Madonna with the Violet "in the Priests' Seminary at Cologne Bellini was able so far to master the new medium that he handed when compared with the somewhat later " Dombild," also by it on with all its possibilities indicated to Giorgione, Palma and Stephan Lochner, which is believed to be painted in oils, but the Titian. That Venetian oil painting however, with all its brilliancy two are still in technical character very nearly akin. The fact and freedom, was a child of the older tempera technique is shown is that tempera panels were usually coated with an oil varnish, by its characteristic method, which consisted in an under-paintnecessarily of a somewhat warm tint, and we could hardly expecting in dead colour, over which were superimposed the transparent to distinguish them from oil pictures painted in or covered by varnish, unless there were a difference in the handling of the pigments. The method of handling appears however to be on the whole the same, and there are many who believe that in all essentials it is the same. Tempera panels, as we have learned from Cennino, were not only varnished but in parts might be painted in oils (ch. 143), and it is one view of the technique of the early Flemings that it was only an over-painting in oils over a preparation in tempera. Berger is of the opinion that the process was something between the two, that is to say, that it was oil tempera, the medium being an emulsion of oil and water through the intermediary of a gum. Such a medium would, as he points out (Beiträge, iii. 247 seq.), combine the thinness and limpidity in manipulation characteristic of a water tempera with the property of drying hard and impervious to moisture. This is of course only a theory. Of far more weight is the suggestion made by Principal Laurie, of Edinburgh, who has carried on for years a series of careful experiments in the various pigments and media employed in oil painting. As one result of these experiments he has found that the ordinary drying oils and oil varnishes do not, as used to be assumed, “lock up" or completely cover and protect pigments so as to prevent the access of moisture and the gases of the atmosphere, but that this function is far more effectively performed by hard pine-balsams, such as Canada balsam, dissolved in an essential oil and so made into a varnish or painting medium. In pictures by Van Eyck Principal Laurie has detected what he believes to be the use of pigments of a notoriously fugitive character, and he is convinced that the most effectual medium for preserving these in the condition in which they have come down to us would be a natural pine-balsam, with probably a small proportion of drying oil; he suggests therefore that the introduction of these ingredients may be the real secret of the Van Eyck technique. There is as yet no proof that the Van Eycks | really used such a medium, though it is a preparation possible at their time, and when thinned by a process of emulsification with egg, as Dr Laurie suggests, would be a serviceable one; but they and the other early oil painters certainly used a method, and in all probability media, that did not differ greatly as regards manipulation from those in vogue in tempera.

From the aesthetic point of view therefore we have to regard early oil painting as only another form of the older tempera,

glazes that secured the characteristic Venetian richness of colouring. Now all the recent writers on the Van Eyck technique agree that, whatever were the exact media employed, the tempera tradition, and perhaps the tempera vehicles, were maintained for the underpainting. In the old tempera-panel technique of Cennino there was a monochrome underpainting in a greenish pigment, over which the flesh tints were spread in thin layers so as never completely to obliterate the ground. Such an underpainting in a few simple colours, black, white and red, was employed by Titian and others of the Venetians, and over it were laid the rich juicy transparent pigments, till "little by little he would have covered with real living flesh these first abstracts of his intention" (Boschini). There is some evidence that in many cases these underpaintings were in tempera, which would have the advantage of drying more quickly than underpaintings in oil, and Boschini (Le Ricche minere della pillura veneziana, 1674) expressly says that the blues in Venetian paintings, e.g. by Veronese, were painted often a guazzo. There was a reason, however, why the Venetians would alter the traditional practice of the Flemish forerunners. The latter were almost entirely panel painters, while the Venetians used canvas. Now certain media, like the hard pine-balsams which Dr Laurie thinks were the basis of the Van Eyck medium, are suitable for the immovable surfaces of a well-grounded panel, but would be liable to crack on canvas which is more or less yielding. Hence the. tougher oil vehicles were in advanced Venetian painting exclusively employed.

This distinction between the thin transparent pigments and those of an opaque body, which is as old as oil painting in any form, becomes in the hands of Bellini and the later Venetians the fundamental principle of the technique. The full advantage of this thinness and transparency is gained by the use of the pigments in question as glazes over a previously laid solid impasto. This impasto may be modelled up in monochrome or in any desired tints chosen to work in with the colours of the superimposed glazes. Effects of colour of great depth and brilliancy may thus be obtained, and after the glaze has been floated over the surface a touch of the thumb, where the underpainting is loaded and lights are required, will so far thin it as to let the underlying colour show through and blend with the deeper tint of the glaze in the shadows. Thus in the noble Veronese in

the London National Gallery, called the "Consecration of St | his own individuality and the special nature of the task before Nicholas," the kneeling figure of the saint is robed in green with him. sleeves of golden orange. This latter colour is evidently carried through as underpainting over the whole draped portions of | the figure, the green being then floated over and so manipulated| that the golden tint shows through in parts and gives the high lights on the folds.