have these limitations been more strictly observed than in that of stained glass in the Middle Ages. In stained glass proper not only is colour necessarily employed in an almost strictly heraldic manner, but the conventions of line are of necessity peculiar. The main outlines of objects are not outlines only, they are also the framework of metal which, while following the contours of forms, has, at the same time, to perform the function of a sash, and hold in position the small bits of glass of which the design is made up. These lines formed by strips or bars of metal are therefore of necessity coarse beyond any used in even the most conventional wall painting. Within the great lines of the lead framework the artist does, it is true, give with the pencil more or less delineation of the finer details of his figures. By applying his neutral pigment either heavily or lightly, and by scratching out lights with the point of a sharpened stick, he can even get considerable gradation in his modellings. But in a general or distant view such elaboration counts for little, and he has to depend mainly for his effect on the coarse general outlines and the patches of flat colours. These peculiarities, growing out of the nature of the materials employed, are not properly to be regarded as imperfections, but as conventions marking the limitations of the art. And even the archaisms of drawing which characterise the figures represented (and which do not grow out of the material conditions, but are largely the imperfections of undeveloped graphic skill) accord so well with the unavoidable conventions that we can hardly conceive of their being changed with good effect.
The art of designing in stained glass would seem to be incapable of real development beyond the conditions that were reached in the Middle Ages. The more modern attempts to give it a wider range, by introducing a more pictorial character, bespeak an imperfect recognition of its inherent principles. In the twelfth century the various resources of overlaying and fusing, by means of which the colours are gradated and blended somewhat as in the art of painting proper, and which have been extensively practised since the fifteenth century, were wholly unknown, and would hardly have been welcomed.
In the apsidal chapels of the Church of St. Denis are
