Field's Chromatography Part 1

Field's Chromatography.

by George Field.

PART I.

ON COLOURS AND COLOURING.

CHROMATOGRAPHY;

OR,

A TREATISE ON COLOURS AND PIGMENTS.

CHAPTER I.

ON COLOURING.

How early, and to what extent, colouring may have attained the rank of science among the ancients, are questions not easily set at rest; but that some progress had been made, even at a very remote period, is proved by the magnificent tombs of the Egyptian kings at Thebes, where the walls of the royal mausoleum are described as being covered with paintings so fresh and perfect, as to require neither restoration nor improvement. So far from this, indeed, that with all care in copying, it was difficult to equal the brilliancy of the originals, which, as far as colours went, threw all others in the background. And yet, in spite of the scale having comprised pure vermilion, ochres, and indigo, it was not gaudy, owing to the judicious balance of the colours, and the artful management of the black. Nor was there an ornament throughout the dresses, wherein the red, yellow, and blue, were not so employed as to produce a delicious harmony.

Moreover, it is stated that in one painting eighty feet high and proportionably broad, which was divided into two ranges of gigantic figures, these were glowing with most exquisite colours, suited to the drapery and naked parts; and in which the azure, yellow, green, &c., were as well preserved as though they had been laid on yesterday. Again, an apartment was discovered among the stupendous ruins at Carnac, on the site of ancient Thebes, one hundred paces wide and sixty deep, completely crowded with pillars, which, together with the ceiling, roof, and walls, were decorated with figures in ba.s.so-relievo, and hieroglyphics--all marvellously beautiful and finely painted, and as fresh, splendid and glorious, after so many ages, as if they had just been finished.

In various accounts these colourings of the Egyptians are described in the warmest terms of admiration. The most charming are undoubtedly those on the tombs and temples: others of less merit have been found on the cases and cloths of mummies, and on papyrus rolls; but it is to the patterns on the walls and ceilings of their houses that they seem to have been most partial, and paid the most attention. The ordinary colours employed by them were red, yellow, green, and blue. Of the last there were two tints; black also was common. For white, the finely prepared stone-coloured ground was deemed sufficient. These colours were occasionally modified by mixture with chalk; but were always, or nearly always, applied singly, in an unmixed state. With regard to their composition, chemical a.n.a.lysis has shown several of the _blues_ to be oxide of copper with a small proportion of iron; none containing cobalt.

There is little doubt, however, that the most brilliant specimens--those which retain all their original force and beauty in the temples of Upper Egypt after an exposure of three thousand years, consist of ultramarine--the celebrated Armenian blue, possibly, of the ancients.

The _reds_ seem for the most part to be composed of oxide of iron mixed with lime, and were probably limited to iron earths and ochres, with a native cinnabar or vermilion. The _yellows_ are said to have been, in many cases, vegetable colours; but it is likely earths and ochres were their chief source. The _greens_ consist of yellow mixed with copper blue. The bluish-green which sometimes appears on Egyptian antiquities, is merely a faded blue. The _blacks_ are both of vegetable and mineral origin, having been obtained from a variety of substances in a variety of ways.

But, as shown by Layard in his discoveries at Nineveh, a knowledge of colouring was not confined to the Egyptians; it was likewise possessed by the a.s.syrians. The painted ornaments of the latter are stated to have been remarkably elegant; and although the colours were limited to blue, red, white, yellow, and black, yet they were arranged with so much taste and skill, and the contrasts were so judiciously preserved, that the combinations were in general agreeable to the eye. The pale yellowish-white ground on which the designs were painted, resembled the tint on the walls of Egyptian monuments, and a strong well-defined black outline was found to be as peculiar a feature in a.s.syrian as in Egyptian painting, black frequently combining with white alone, or alternating with other colours. As far as they have been a.n.a.lysed, the pigments employed were mineral, the brightest being a blue derived from copper.

No traces of vegetable colours have been found; it is presumed that they existed, but being subject to more rapid decay than the mineral pigments, they have disappeared. That all the colours, indeed, employed by the ancients were not permanent, was proved by the fact of certain blues and reds, brilliant and vivid when the earth was removed from them, fading rapidly when exposed to the air.

From Philocles, the Egyptian, and Gyges, a Lydian, both of whom, according to Pliny, acquired the knowledge of the art of painting in Egypt, the Greeks obtained the knowledge of their _Ars Chromatica_, which they are said to have carried by gradual advances during several centuries, from the monochromatic of their earlier painters, to the perfection of colouring under Zeuxis and Apelles, 450 to 350 B.C.

Unfortunately, not long after, or about 300 B.C., art rapidly deteriorated; the invasion of the Romans commenced; and the principles of light, shade, and colours in painting as understood by the Greeks, together with their valuable treatises on the subject were lost. The early Roman and Florentine painters, so eminent in other respects, were almost dest.i.tute of those principles, and of truly refined feeling for the effects of colouring.

The partial restoration of this branch seems to have been coeval with the earliest practice of painting in oil. The glory of it belongs to the Venetians, to whom the art of painting pa.s.sed with the last remains of the Greek schools after the capture of Constantinople at the beginning of the thirteenth century. Giovanni Bellini laid the foundation of colouring, and t.i.tian carried it to its highest practical perfection.

From the Venetian it extended to the Lombard, Flemish, and Spanish schools. In the practice of these, however, there was perhaps as much of instinct as principle, colouring still remaining to be established in its perfection as a science.

According to the true, natural, and philosophical cla.s.sification of painting, there are but three princ.i.p.al cla.s.ses or schools; viz.: the gross and _material_ which is content with mere nature, and to which belong the Dutch and Flemish schools; the _sensible_, which aims at refined and select nature, and accords with the Venetian school; and the _intellectual_, which aspires to the ideal in beauty, grandeur, and sublimity, and corresponds with the Greek, Roman, and Florentine schools. Modern art as founded upon the _intellectual_ school of the ancient Greeks, became grand, scientific, and severe in the practice of Michael Angelo, and Leonardo da Vinci; graceful, beautiful and expressive in Raphael, Correggio, Dominichino, and Guido; and, aiming at _sensible_ perfection, it attained harmony of colouring and effect in the works of t.i.tian and Tintoret; but it sunk into grossness and sensuality while perfecting itself _materially_ among the Flemish and Dutch.

In the practice of the individual in painting, as well as in all revolutions of pictorial art, in ancient Greece as in modern Italy, colouring in its perfection has been the last attainment of excellence in every school. It has been justly observed, indeed, that for near three hundred years, since painting was revived, we could hardly reckon six painters that had been good colourists, among the thousands who had laboured to become such. But there is reason to hope that as Zeuxis succeeded and excelled Polygnotus, and t.i.tian Raphael, the artists of Britain will transcend all preceding schools in the chromatic department of painting. It is even probable that they may surpa.s.s them in all other branches, and in every mode and application of the art, as they have already more particularly done in an original and unrivalled use of water-colours.

Happily, too, there has arisen among us a school of colouring that confirms this expectation, strengthened as it is, by the suitableness of our climate to perfect vision. For in it we have that mean degree of light which is best adapted to the distinguishing of colours, a boundless diversity of hue in nature relieved by those fine effects of light and shade which are denied to more vertical suns, besides those beauties of complexion and feature in our females peculiar to England; respects in which at least our country is not unfavourable to art.

Even now it is urged by some to the _disparagement_ of the British school, that it excels in colouring; as if this were incompatible with any other excellence, or as if nature, the great prototype of art, ever dispensed with it. The graphic branches of painting, owe everything to colour, which, if it does not const.i.tute a picture, is its flesh and blood. Without it, the finest performances remain lifeless skeletons, and yield no pleasure. Painting is the art of representing visible things by light, shade, form, and colour; but of these, colour--and colour alone--is the immediate object which attracts the eye. Colouring is, therefore, the first requisite--the one thing imparting warmth and life--the chief quality engaging attention; in short, the best introduction to a picture, and that which continues to give it value so long as it is regarded. It is a power, too, which is with the most difficulty retained, being the first to leave the artist himself, and the first to quit a school on its decline. Graphic art without colouring, is as food without flavour; and it was the deficiency of colouring in the great works of the Roman and Florentine schools that caused Sir Joshua Reynolds to confess a certain want of attraction in them. To relish and estimate truly their greatness, required, he said, a forced and often-repeated attention, and "it was only those persons incapable of appreciating such divine performances, who made pretensions to instantaneous raptures on first beholding them." Gainsborough also, with a candour similar to that of Reynolds, upon viewing the cartoons at Hampton Court, acknowledged that their beauty was of a cla.s.s he could neither appreciate nor enjoy.

Colouring, then, is a necessity; but there is in it a vicious extreme; that in which it is rendered so princ.i.p.al as, by want of subordination, to overlay the subject. There is also a negative excellence which consists in not always employing pleasing tints, but of sometimes taking advantage of the effects to be derived from impure hues, as Poussin did in his "Deluge." In this work, neither black nor white, blue, red, nor yellow appears; the whole ma.s.s being, with little variation, of a sombre grey, the true resemblance of a dark and humid atmosphere, by which every object is rendered indistinct and almost colourless. This absence of colour, however, is a merit, and not a fault. Vand.y.k.e employed such means with admirable effect in the background of a Crucifixion, and in his Pieta; and the Phaeton of Giulio Romano is celebrated for a suffusion of smothered red, which powerfully excites the idea of a world on fire.

Of the rank and value of this department of painting, there will be, as there has been, difference of judgment and opinion, as there is variety in the powers of the eye and understanding. But take from Rubens, Rembrandt, t.i.tian, and other distinguished masters, the estimation of their colouring, and we fear all that is left to them would hardly preserve their names from oblivion. Art cannot, indeed, attain its appropriate end, that of pleasing, without excellence in colouring. It is colour which the true artist most loves, and it is colouring in all its complex and high relations, that he ever seeks to attain. Looking above, and around, and beneath him, with the intelligent eye of the colourist, he finds a boundless source of never-ceasing enjoyment. With harmonies and accordances lost to the untutored gaze, colour meets him in every stone he treads on--in the mineral, vegetable, and animal creation--in the heavens, sea, and earth. For him, in truth, colour is as equally diffused as light, spreading itself over the entire face of nature, and clothing the whole world with beauty.

CHAPTER II.

ON THE RELATIONS AND HARMONY OF COLOUR.

a.s.sured as we must be of the importance of colouring as a branch of art, colours in all their bearings become interesting to the artist, and on their use and arrangement his reputation as a colourist must depend.

Colour, remarks Ruskin, is wholly _relative_; each hue throughout a work is altered by every touch added in other places. Thus, to place white beside a colour is to heighten its tone; to set black beside a colour is to weaken its tone; while to put grey beside a colour, is to render it more brilliant. If a dark colour be placed near a different, but lighter colour, the tone of the first is heightened, while that of the second is lowered. An important consequence of this principle is, that the first effect may neutralize the second, or even destroy it altogether. What was cold before, becomes warm when a colder colour is set near it, and what was in harmony before, becomes discordant as other colours are put beside it. For example, to place a light blue beside a yellow, tinges it orange, and consequently heightens its tone. Again, there are some blues so dark relatively to the yellow that they weaken it, and not only hide the orange tint, but even cause sensitive eyes to feel that the yellow is rather green than orange--a very natural result when it is considered that the paler the yellow becomes, the more it tends to appear green.

We learn from these relations of colours, why dapplings of two or more produce effects in painting so much more clear and brilliant than uniform tints obtained by compounding the same colours: and why hatchings, or a touch of their contrasts, thrown as it were by accident upon local tints, have the same effect. We see, too, why colours mixed deteriorate each other, which they do more--in many cases--by imperfectly neutralizing or subduing each other chromatically, than by any chemical action. Finally, we are impressed with the necessity, not only of using colours pure, but of using pure colours; although pure colouring and brilliancy differ as much from crudeness and harshness, as tone and harmony from murkiness and monotony.

The powers of colours in contrasting each other agree with their correlative powers of light and shade, and are to be distinguished from their powers individually on the eye, which are those of light alone.

Thus, although orange and blue are equal powers with respect to each other, as regards the eye they are totally different and opposed. Orange is a luminous colour, and has a powerfully irritating effect, while blue is a shadowy colour, possessing a soothing quality--and it is the same, in various degrees, with other colours.

There are yet further modes of contrast or antagonism in colouring, which claim the attention and engage the skill of the colourist. Of the contrast of _hues_, upon which depend the brilliancy, force, and harmony of colouring, we have just spoken; but there is, secondly, the contrast of _shades_. To this belong all the powers of chiaroscuro, by which term the painter denotes the harmonious effects of light and shade; and though they form the simplest part of colouring, yet they cannot be separated from it--light and shade, the chiaroscuro, being a distinct and important branch of painting. A third mode of contrast in colouring is that of _warmth_ and _coolness_, upon which depend the toning and general effect of a picture. Fourthly, there is the contrast of _colour_ and _neutrality_, the chromatic and achromatic, or hue and shade. By the right management of this, local colours acquire value, gradation, keeping, and connection: whence come breadth, aerial perspective, and the due distribution of greys and shadows in a picture.

This principle of contrast applies even to _individual colours_, and conduces greatly to good colouring. It may be carried with advantage into the variety of hue and tint in the same colour, not only as regards light and shade, but likewise with respect to warmth and coolness, as well as to colour and neutrality. Hence the judicious landscape-painter knows how to avail himself of warmth and coolness in the juxtaposition of his greens, in addition to their lightness and darkness, or brilliancy and brokenness, in producing the most beautiful and varied effects; effects which spring in other cases from a like management of blue, white, &c. These powers of a colour upon itself are highly important to the artist, and lead to that gratification from fine colouring, which a good eye ever enjoys.

In landscape we see nature employing broken colours in harmonious consonance and variety, while, equally true to picturesque relations, she uses also broken forms and figures, in conjoint harmony with colours; occasionally throwing into the composition a regular form, or a primary colour, for the sake of animation and contrast. And if we inspect her works more closely, we shall find that they have no uniform tints. Whether in the animal, vegetable or mineral creation--flesh or foliage, earth or sky, flower or stone--however uniform the colour may appear at a distance, it will, when examined nearly, be found to consist of a variety of hues and shades, compounded with harmony and intelligence.

It is for this reason that no two colours are ever found discordant in nature, however much so they may be in art. Blue and green have been termed discordant, and in painting they may undoubtedly be made so. Yet those are two colours which nature seems to intend never to be separated, and never to be felt, either of them, in its full beauty, without the other--a blue sky through green leaves, or a blue wave with green lights through it, being precisely the loveliest things, next to clouds at sunrise, in this coloured world of ours. A good eye for colour will soon discover how constantly nature puts green and purple together, purple and scarlet, green and blue, yellow and neutral grey, and the like; and how she strikes these colour-concords for general tones, before working into them with innumerable subordinate ones.

Upon the more intimate union, or the blending and gradience of contrasts from one to another mutually, depend some of the most fascinating effects of colouring. The practical principle employed in producing them is important, and consists in the blending and gradating by _mixture_, while we avoid the _compounding_ of contrasting colours. That is, the colours must be kept distinct in the act of blending them, or otherwise they will run into dusky neutrality and defile each other. This is the case in blending and gradating from green to red, or from hue to hue--from blue to orange, or to and from coldness and warmth--from yellow to purple, or to and from advancing and retiring colours. It is the same in light and shade, or white and black, which _mix_ with clearness. Now, there are only two ways in which this distinctness in union of contrasts can be effected in practice: the one is by hatching or breaking them together in mixture, without compounding them uniformly; and the other is by glazing, in which the colours unite and penetrate mutually, without monotonous composition.

The former process may be said to be the carrying out of the principle of separate colours to the utmost possible refinement, by using atoms of colour in juxtaposition, instead of in large s.p.a.ces. And it is to be noted, in filling up minute interstices of this kind, that if the colour with which they are filled be wanted to show brightly, a rather positive point of it had better be put, with a little white left beside or round it in the interstice. This plan is preferable to laying a pale tint of the colour over the whole interstice. Yellow or orange, for instance, will hardly show, if pale, in small s.p.a.ces; but they show brightly in free touches, however small, with white beside them. The latter mode is founded on the fact, that if a dark colour be laid first, and a little blue or white body-colour struck lightly over it, a more beautiful gray will be obtained than by mixing the colour and the blue or white.

Similarly, if over a solid and perfectly dry touch of vermilion there be quickly washed a little very wet carmine, a much more brilliant red will be produced than by mixing the two colours.

Transparency and opacity const.i.tute another contrast of colouring, the former of which belongs to shade and blackness, the latter to light and whiteness. Even contrast has its contrast, for _gradations_ or _intermedia_ are opposed to contrasts or _extremes_; and, upon the right management of contrasts and gradations depend the harmony and melody, the tone, effect, and general expression of a picture. Thus, painting is an affair of judicious contrasting so far as regards colour, if even it be not such altogether.

Colour, it has already been observed, is wholly _relative_. In contrasting, therefore, any colour, if we wish it to have light or brilliancy, we cast its opposite into the shade; if we would have it warm, we cool its antagonist; and if transparent, we oppose it by an opaque contrary, and _vice versa_: indeed, in practice, all these must be in some measure combined.

Such are some of the powers of contrast in colouring alone, and such is the diversity of art upon which skill in colouring depends. It must not be forgotten, however, that contrasts or extremes, whether of light and shade, or of colours, become violent and offensive when they are not reconciled by the interposition of their media, or intermediates, which partake of both extremes of the contrasts. Thus blue and orange in contrast become reconciled, softened in effect, and harmonized, when a broken colour composed of the two intervenes. The same may be said of other colours, shades, and contrasts.

Seeing that the management and mastery of colours are to a great extent dependent on the same principles as light and shade, it might become a point of good discipline, after acquiring the use of black and white in the chiaroscuro, to paint designs in contrast; that is, with two contrasting colours only, in conjunction with black and white--for example, with blue and orange, before attempting the whole. Indeed, black can be dispensed with in these cases, because it may be compounded, since the neutral grey and third colours always arise from the compounding of contrasting colours. In this way, even flesh may be painted--for instance, with red and green alone, as Gainsborough is said at one period to have done.

Some artists have produced pictures in the above hot and cold colours only; which, although captivating to the eye, and true in theory with respect to colour, light and shade, are generally false in practice with regard to nature, which rarely employs such extreme accordances.

Colouring like this, therefore, is more beautiful than true. It is as though a painter were to execute a landscape in the full light of day, as he saw it looking through a prism, so that every object glowed with rainbow hues. Such a picture would present a beautiful fairy scene, and be true as regards colours, but as respects nature, it would be false.