I had intended in one or other of these lectures to have spoken at some length of the quality of refinement in Colour, but found the subject would lead me too far. A few words are, however, necessary in order to explain some expressions in the text.

"Refinement in colour" is indeed a tautological expression, for colour, in the true sense of the word, does not exist until it is refined. Dirt exists,—stains exist,—and pigments exist, easily enough in all places; and are laid on easily enough by all hands; but colour exists only where there is tenderness, and can be laid on only by a hand which has strong life in it. The law concerning colour is very strange, very noble, in some sense almost awful. In every given touch laid on canvas, if one grain of the colour is inoperative, and does not take its full part in producing the hue, the hue will be imperfect. The grain of colour which does not work is dead. It infects all about it with its death. It must be got quit of, or the touch is spoiled. We acknowledge this instinctively in our use of the phrases "dead colour," "killed colour," "foul colour." Those words are, in some sort, literally true. If more colour is put on than is necessary, a heavy touch when a light one would have been enough, the quantity of colour that was not wanted, and is overlaid by the rest, is as dead, and it pollutes the rest. There will be no good in the touch.

The art of painting, properly so called, consists in laying on the least possible colour that will produce the required result, and this measurement, in all the ultimate, that is to say, the principal, operations of colouring, is so delicate that not one human hand in a million has the required lightness. The final touch of any painter properly so named, of Correggio—Titian—Turner—or Reynolds—would be always quite invisible to any one watching the progress of the work, the films of hue being laid thinner than the depths of the grooves in mother-of-pearl. The work may be swift, apparently careless, nay, to the painter himself almost unconscious. Great painters are so organized that they do their best work without effort: but analyze the touches afterwards, and you will find the structure and depth of the colour laid mathematically demonstrable to be of literally infinite fineness, the last touches passing away at their edges by untraceable gradation. The very essence of a master's work may thus be removed by a picture- cleaner in ten minutes.

Observe, however, this thinness exists only in portions of the ultimate touches, for which the preparation may often have been made with solid colours, commonly, and literally, called "dead colouring," but even that is always subtle if a master lays it—subtle at least in drawing, if simple in hue; and farther, observe that the refinement of work consists not in laying absolutely little colour, but in always laying precisely the right quantity. To lay on little needs indeed the rare lightness of hand; but to lay much,—yet not one atom too much, and obtain subtlety, not by withholding strength, but by precision of pause,—that is the master's final sign-manual—power, knowledge, and tenderness all united. A great deal of colour may often be wanted; perhaps quite a mass of it, such as shall project from the canvas; but the real painter lays this mass of its required thickness and shape with as much precision as if it were a bud of a flower which he had to touch into blossom; one of Turner's loaded fragments of white cloud is modelled and gradated in an instant, as if it alone were the subject of the picture, when the same quantity of colour, under another hand, would be a lifeless lump.

The following extract from a letter in the Literary Gazette of 13th November, 1858, which I was obliged to write to defend a questioned expression respecting Turner's subtlety of hand from a charge of hyperbole, contains some interesting and conclusive evidence on the point, though it refers to pencil and chalk drawing only:—

"I must ask you to allow me yet leave to reply to the objections you make to two statements in my catalogue, as those objections would otherwise diminish its usefulness. I have asserted that, in a given drawing (named as one of the chief in the series), Turner's pencil did not move over the thousandth of an inch without meaning; and you charge this expression with extravagant hyperbole. On the contrary, it is much within the truth, being merely a mathematically accurate description of fairly good execution in either drawing or engraving. It is only necessary to measure a piece of any ordinary good work to ascertain this. Take, for instance, Finden's engraving at the 180th page of Rogers' poems; in which the face of the figure, from the chin to the top of the brow, occupies just a quarter of an inch, and the space between the upper lip and chin as nearly as possible one-seventeenth of an inch. The whole mouth occupies one-third of this space, say one- fiftieth of an inch, and within that space both the lips and the much more difficult inner corner of the mouth are perfectly drawn and rounded, with quite successful and sufficiently subtle expression. Any artist will assure you that in order to draw a mouth as well as this, there must be more than twenty gradations of shade in the touches; that is to say, in this case, gradations changing, with meaning, within less than the thousandth of an inch.

"But this is mere child's play compared to the refinement of a first- rate mechanical work—much more of brush or pencil drawing by a master's hand. In order at once to furnish you with authoritative evidence on this point, I wrote to Mr. Kingsley, tutor of Sidney-Sussex College, a friend to whom I always have recourse when I want to be precisely right in any matter; for his great knowledge both of mathematics and of natural science is joined, not only with singular powers of delicate experimental manipulation, but with a keen sensitiveness to beauty in art. His answer, in its final statement respecting Turner's work, is amazing even to me, and will, I should think, be more so to your readers. Observe the successions of measured and tested refinement: here is No. 1:—

"'The finest mechanical work that I know, which is not optical, is that done by Nobert in the way of ruling lines. I have a series ruled by him on glass, giving actual scales from .000024 and .000016 of an inch, perfectly correct to these places of decimals, and he has executed others as fine as .000012, though I do not know how far he could repeat these last with accuracy.'

"This is No. 1 of precision. Mr. Kingsley proceeds to No. 2:—

"'But this is rude work compared to the accuracy necessary for the construction of the object-glass of a microscope such as Rosse turns out.'

"I am sorry to omit the explanation which follows of the ten lenses composing such a glass, 'each of which must be exact in radius and in surface, and all have their axes coincident:' but it would not be intelligible without the figure by which it is illustrated; so I pass to Mr. Kingsley's No. 3:—

"'I am tolerably familiar,' he proceeds, 'with the actual grinding and polishing of lenses and specula, and have produced by my own hand some by no means bad optical work, and I have copied no small amount of Turner's work, and I still look with awe at the combined delicacy and precision of his hand; IT BEATS OPTICAL WORK OUT OF SIGHT. In optical work, as in refined drawing, the hand goes beyond the eye, and one has to depend upon the feel; and when one has once learned what a delicate affair touch is, one gets a horror of all coarse work, and is ready to forgive any amount of feebleness, sooner than that boldness which is akin to impudence. In optics the distinction is easily seen when the work is put to trial; but here too, as in drawing, it requires an educated eye to tell the difference when the work is only moderately bad; but with "bold" work, nothing can be seen but distortion and fog: and I heartily wish the same result would follow the same kind of handling in drawing; but here, the boldness cheats the unlearned by looking like the precision of the true man. It is very strange how much better our ears are than our eyes in this country: if an ignorant man were to be "bold" with a violin, he would not get many admirers, though his boldness was far below that of ninety-nine out of a hundred drawings one sees.'

"The words which I have put in italics in the above extract are those which were surprising to me. I knew that Turner's was as refined as any optical work, but had no idea of its going beyond it. Mr. Kingsley's word 'awe' occurring just before, is, however, as I have often felt, precisely the right one. When once we begin at all to understand the handling of any truly great executor, such as that of any of the three great Venetians, of Correggio, or Turner, the awe of it is something greater than can be felt from the most stupendous natural scenery. For the creation of such a system as a high human intelligence, endowed with its ineffably perfect instruments of eye and hand, is a far more appalling manifestation of Infinite Power, than the making either of seas or mountains.

"After this testimony to the completion of Turner's work, I need not at length defend myself from the charge of hyperbole in the statement that, 'as far as I know, the galleries of Europe may be challenged to produce one sketch [footnote: A sketch, observe,—not a finished drawing. Sketches are only proper subjects of comparison with each other when they contain about the same quantity of work: the test of their merit is the quantity of truth told with a given number of touches. The assertion in the Catalogue which this letter was written to defend, was made respecting the sketch of Rome, No. 101.] that shall equal the chalk study No. 45, or the feeblest of the memoranda in the 71st and following frames;' which memoranda, however, it should have been observed, are stated at the 44th page to be in some respects 'the grandest work in grey that he did in his life.' For I believe that, as manipulators, none but the four men whom I have just named (the three Venetians and Correggio) were equal to Turner; and, as far as I know, none of those four ever put their full strength into sketches. But whether they did or not, my statement in the catalogue is limited by my own knowledge: and, as far as I can trust that knowledge, it is not an enthusiastic statement, but an entirely calm and considered one. It may be a mistake but it is not a hyperbole."