159. C. By the true 'Providence' of Nature, the rock which is thus submissive has been in some places stained with the fairest colors, and in others blanched into the fairest absence of color that can be found to give harmony to inlaying, or dignity to form. The possession by the Greeks of their [Greek: leukos lithos] was indeed the first circumstance regulating the development of their art; it enabled them at once to express their passion for light by executing the faces, hands, and feet of their dark wooden statues in white marble, so that what we look upon only with pleasure for fineness of texture was to them an imitation of the luminous body of the deity shining from behind its dark robes; and ivory afterwards is employed in their best statues for its yet more soft and flesh-like brightness, receptive also of the most delicate color--(therefore to this day the favorite ground of miniature painters). In like manner, the existence of quarries of peach-colored marble within twelve miles of Verona, and of white marble and green serpentine between Pisa and Genoa, defined the manner both of sculpture and architecture for all the Gothic buildings of Italy. No subtlety of education could have formed a high school of art without these materials. 160. Next to the color, the fineness of substance which will take a perfectly sharp edge, is essential; and this not merely to admit fine delineation in the sculpture itself, but to secure a delightful precision in placing the blocks of which it is composed. For the possession of too fine marble, as far as regards the work itself, is a temptation instead of an advantage to an inferior sculptor; and the abuse of the facility of undercutting, especially of undercutting so as to leave profiles defined by an edge against shadow, is one of the chief causes of decline of style in such incrusted bas-reliefs as those of the Certosa of Pavia and its contemporary monuments. But no undue temptation ever exists as to the fineness of block fitting; nothing contributes to give so pure and healthy a tone to sculpture as the attention of the builder to the jointing of his stones; and his having both the power to make them fit so perfectly as not to admit of the slightest portion of cement showing externally, and the skill to insure, if needful, and to suggest always, their stability in cementless construction. Plate X. represents a piece of entirely fine Lombardic building, the central portion of the arch in the Duomo in Verona, which corresponds to that of the porch of San Zenone, represented in Plate I. In both these pieces of building, the only line that traces the architrave round the arch, is that of the masonry joint; yet this line is drawn with extremest subtlety, with intention of delighting the eye by its relation of varied curvature to the arch itself; and it is just as much considered as the finest pen-line of a Raphael drawing. Every joint of the stone is used,