[1] Leonardo da Vinci observes: "L'ombra è diminuzione di luce, tenebre è privazione di luce." And again: "Sempre il minor lume è ombra del lume maggiore."--_Trattato della Pittura_, pp. 274-299. N. B. The same edition before described has been consulted throughout. [2] "Lux varium vivumque dabit, nullum umbra colorem." _De Arte Graphicá_. "Know first that light displays and shade destroys Refulgent nature's variegated dies."--Mason's _Translation_. [3] A Spanish writer, Diego de Carvalho e Sampayo, quoted by Goethe ("Farbenlehre," vol. ii.), has a similar observation. This destroying effect of light is striking in climates where the sun is powerful, and was not likely to escape the notice of a Spaniard. [4] Trattato, pp. 103, 121, 123, 324, &c. [5] Ib. pp. 85, 134. [6] Absolute opacity, to judge from the older specimens of stained glass, seems to have been considered inadmissible. The window was to admit light, however modified and varied, in the form prescribed by the architect, and that form was to be preserved. This has been unfortunately lost sight of in some modern glass-painting, which, by excluding the light in large masses, and adopting the opacity of pictures (the reverse of the influence above alluded to), has interfered with the architectural symmetry in a manner far from desirable. On the other hand, if we suppose painting at any period to have aimed at the imitation of stained glass, such an imitation must of necessity have led to extreme force; for the painter sets out by substituting a mere white ground for the real light of the sky, and would thus be compelled to subdue every tone accordingly. In such an imitation his colour would soon deepen to its intensest state; indeed, considerable portions of the darker hues would be lost in obscurity. The early Flemish pictures seldom err on the side of a gay superabundance of colour; on the contrary, they are generally remarkable for comparatively cool lights, for extreme depth, and a certain subdued splendour, qualities which would necessarily result from the imitation or influence in question. [7] See Langlois, "Peinture sur Verre." Rouen, 1832; Descamps, "La Vie des Peintres Flamands;" and Gessert, "Geschichte der Glasmalerei." Stutgard, 1839. The antiquity of the glass manufactory of Murano (Venice) is also not to be forgotten. Vasari objects to the Venetian glass, because it was darker in colour than that of Flanders, France, and England; but this very quality was more likely to have an advantageous influence on the style of the early oil-painters. The use of stained glass was, however, at no period very general in Italy.