But while light-and-shade enters into the relations of everything in the visible world its presence in small quantities is little noted by us, perhaps for the very reason that it is so common. A tree is simply green to us, and stands against its back ground somewhat like a palm-leaf fan against a wall ; we do not always notice the yellow-greens, the emerald-greens, and the dark-greens, scattered through it, that give it diversity, depth, roundness, volume. A human face is known to us by its features or lines ; we seldom see its lights and shades the high lights on the nose, cheek, chin, and fore-head ; the deep shadows under the nose, under the chin, and around the sides of the throat. A water-bottle never strikes us as being in anyway marked by light-and-shade, yet there is always a line of white light running up and down or across it, ac-cording to the direction from which the light comes. If this water-bottle were of iridescent glass we should notice the line of light instantly because it would be colored, just as we should notice the changing hues of an opal upon our hand ; but these objects in reality possess no more light-and-shade than an ordinary glass or an ivory button. The light is simply more apparent because it is colored ; it is not more real.
Every visible tangible thing has its relief by contrasts of light with shade, and if, as I have intimated, we do not always see them, it is because we are not shrewd observers of the phenomenon of light, common though it be. A few days ago I was trying to point out to a school-boy the lights and shades on a polished copper tankard which he was endeavoring to draw on a sheet of paper. He protested that he could not see them. The prevailing copper color of the tankard had blinded him to the shadow gradations. We are all more or less like him in short-sightedness. Our observation is not keen enough to note the delicate transitions that nature makes. And so we draw upon all the resources of the earth to provide ourselves with great artificial eyes where-with to see the light of some distant world, and yet we cannot see the light on the petal of a buttercup growing beneath our window. It is well that the artist lives to point out to us these minor beauties that exist in the world about us.
The necessities of good art require that every object which is of sufficient importance to have light must also be accounted of sufficient importance to have its proper amount of shade. I say “proper amount” because there is no rule elastic enough to cover all objects in nature and state what that amount should be. An apple needs more shade than a book, a book more than a flat sheet of paper, and so on through a thousand variations in the relative quantities of light and of shade dependent upon the objects reflecting them. The eye alone can say what is an adequate or proper balance.
As for the transition from the highest light to the deepest dark, it should usually be made by delicate gradations. “As smoke loses itself in the air, so are your lights and shadows to pass from one to the other without any apparent separation,” says Leonardo, and his ” sfumato ” is the pictorial illustration of his teaching. The violent change will not do as a rule, for nature is not violent, except occasionally and in small masses at that. A rift of sunlight sometimes falls through a chink of a wall and makes a thread of silver in a dungeon’s gloom, and often the shadow of a hollow rock, the sunlight on a window-pane, make sharp contrasts of light with shade ; but the sharpness is specially not generally true of nature. To be sure the very subtile transition which Leonardo recommends, occasionally results in wooliness of textures ; but, on the other hand, the sharp contrast which some of the painters use to-day more often results in hardness of line and absence of atmosphere. There is a middle ground upon which good art may stand, and if there be any leaning to the one side or the other it should be in favor of delicate gradation. The violent may prove strong in the hands of genius, but in the hands of the ordinary painter it shows only a pretentious weakness.
The pitch of light may be regarded as not of vital importance provided it be balanced with a proportionate pitch of shadow. It is not nature’s heights or depths that the painter may reproduce, but only her proportions. No pigment, however brilliant, could possibly reach the brightness of sunlight, nor was there ever a night scene painted that closely approached the depth of the night shadows; but the proportioning of the lights to the shadows will give us the effect, if not the extent, of either scene. When a singer cannot reach certain notes in the musical scale he adjusts the difficulty by transposing the scale yet retaining the relationship. The painter produces the effect of great brightness or darkness in a similar manner.
Proportion and gradation, then, form the great law of light-and-shade to which a picture must pay deference not only in its individual objects but as a whole. For when light-and-shade is considered as it affects the whole picture, it becomes not less like chiaroscuro but more like composition. That is to say, its arrangement rules the composition of the picture to a certain extent. Thus in a landscape the relief of each object by its light and its shade may not be sufficient in itself to render the picture attractive and pleasing, though it may be absolutely true to nature and realistic enough for an exclamation point. A stretch of desert in sunlight, with never a tree nor mound nor building to cast a shadow, may be nature itself ; but if we should look upon either the original, or its counterfeit presentment on canvas, we should be dazzled, and perhaps annoyed, by its garishness, its bewildering light, its monotony. The eye could find no relief in such a scene, and necessarily it would not be attractive. So again, if a green landscape under sunlight contained no large shadow-masses to balance the large masses of light and give relief to the eye, we might find the same objection. The shadows may be intermixed or in masses, as the painter wills, each object may have its light and cast its shadow and thus make up the proportions of light to dark, or great belts of light and shade may be thrown along the landscape by partly obscuring the sun with clouds ; but however it is done it seems necessary to good art that the aggregate of shade should be sufficient to relieve the mass of lights and dispel garishness.
The exact proportion of the light to the dark is something that no one can stereotype in rule. Some artists talk of one-sixth deep shadow, two-sixths light, and the balance a large middle tint, or they may give formulas of a similar nature corresponding to their experience ; but we would bet-ter not rely upon any say-so whatever, other than what we can extract from the sensitiveness of the eye. Dannat’s fine picture in the Metropolitan Museum in New York, of four people singing in a Spanish cabaret, appears to be more than half made up of shadow, but the shadows are rightly proportioned to the lights, at least there is no feeling of blackness about them. The light coming through a break in the lattice is not large in volume, but it is sufficient, and as a whole the picture gives us a sensation of pleasure. If, however, in the same museum, we move along some steps until, on the same wall, we come before Meissonier’s celebrated Napoleonic picture of “Friedland, 1807,” we shall experience a sudden and a disagreeable change. The first picture is as restful and refreshing to the eyes as a deep wood-interior in August ; the second picture has a glare and a flare about it, a heated blistering light that irritates like a southern sea at noonday. Swords and helmets gleam ; uniforms, men’s faces, horses’ coats, look white or brick red ; the sky and distance are full of light ; but there is not a tree nor shrub nor hill nor house to cast a shadow in which the eye could find a momentary relief from the glare. The shadows of individual objects are true enough ; the sword-blade, the check-rein, the horse and rider throw their shadows, but the aggregate of them all is not sufficient to balance the power of the lights. That which the picture needs is relieving masses of shadow, which the eye now seeks for in vain. In its present state it appears to have about ninety per cent. of light and ten per cent. of shadow and, as a result, the spectator feels the need of cobalt-blue glasses in looking at it for any considerable length of time.
The reverse of surplus light is, of course, surplus shadow. We often hear painters speak of pictures as ” too black,” which may mean that the whole pitch of light is too low, or that the shades alone are too dark. The works of Jacopo Bassano of the Venetian school, in their present condition, are good instances of extreme shadow-depths ; though it is right to say that they have partly become so by time, and were not originally painted as they now appear. Some of Munkacsy’s pictures painted with bitumen are open to the same criticism of blackness, and Goya’s works are not always free from it, how-ever powerful they may be in other respects. Courbet, too, has at times given exaggerated strength to his shadows, and at other times he has pitched pictures so low in key as to make one think that when he painted them the sun had become black as sackcloth of hair after the manner told in the Apocalypse. To be sure this blackness is not characteristic of all the works of either Goya or Courbet, and I have only spoken of their exceptional pictures in this respect. Perhaps better instances could be found in the works of painters like Caravaggio, Ribera, and Ribot. My use of the words ” black ” and “blackness,” you will understand as being comparative only. Black is not a shadow but a total absence of light. Shadows, in the majority of pictures, are colors of some sort, having a certain amount of warmth and luminosity to them. Black is opaque and cold, and if you care to see how different it is from a shadow, examine the black. cloth or velvets painted by Velasquez or Goya, and compare them with the shadows in the same pictures.
Gradation of light or color from a fixed centre is perhaps a matter of composition again, but it may not inappropriately come in here, since the lightand-shade problem, with which it deals, is now before us. In the first place, the light which illumines any sort of a pictorial composition is usually brought from one point of the heavens and made to prevail from that point throughout the entire piece. Lights from different quarters are likely to be conflicting, and oftentimes confusing, rendering a task already hard enough to execute doubly difficult. But the difficulty of technical problems is an attraction to some artists, so that while the great number of pictures of the past and of the present may be found to have light from but one direction, you will find other pictures where the lights are doubled and sometimes tripled. Thus you will see among landscapes many early moonrise pictures in which the twilight and the moonlight struggle for the mastery ; you will see pictures of interiors in which the light comes from opposing windows ; and you will sometimes see lamplight conflicting with daylight. These pictures, while revealing cleverness in the handling of the different illuminations, can hardly be set down as any great improvement on the handling of one light, which, as I have said, we shall find in the majority of paintings.