THE term "stained glass" applies, if we go to the root of the matter, to all glass which, by the addition of some metallic oxide to the ingredients, has been coloured in the melting pot. Strictly speaking, the Sham jewels Of the ancients, the Portland Vase and the little phials zigzagged with blue, white, and yellow, are stained glass. But that is not what the words imply. They have been, as it were, appropriated, and are commonly taken in a more limited sense. "Stained glass" is understood to signify windows, the production of which (beginning as it practically did with Gothic Architecture, or, at the earliest, with the Byzantine and Romanesque out of which it was just emerging, and declining after the early part of. the Sixteenth century, when the Renaissance still owed much to the survival Of Gothic tradition) was an art, we may say, identified with the Middle Ages. No art certainly is more thoroughly informed with the spirit we call Gothic. It naturally followed the course of Mediaeval design, and differs from enamel, sculpture, illumination, wall painting, and so forth, 'only in as much as the nature of the material and the exigencies Of its manipulation made special treatment necessary, or as the qualities of the glass tempted the worker in the direction of its peculiar beauties.'The design of a window is, mutatis mutandis, that of a seal, an ivory, a brass, a monument. Windows are set out on a grand scale much on the same lines as triptychs and other devotional panels of the same period are designed in small, with subjects in medallions, or in panels, with figures under canopies, and pictures gradually as years went on more pictorially conceived. "And in the character of the drawing and detail, there is no wide difference between glass-painting and other crafts. Such as it is, it is due more to the conditions of cutting, glazing, and painting upon glass, and to the way a window is built up, than to any determination on the part of the artist to go his own way. No doubt he made the most of the gorgeous quality of vitreous colour but so did the enameller, whose work alone is comparable to it in this respect.'... Stained glass, as the term is used, is taken to include also painting upon the glass. 'As a matter of fact, glass staining and glass painting are two quite different things. To build up a mosaic with pieces of coloured glass, each separate tint cut out of a separate sheet of "Pot-metal," is one thing; to paint upon a sheet of white or coloured glass is another thing altogether. 'In fact, they are not merely two different ways but two opposite ways of arriving at a result. But there is .this excuse for grouping them (as it is the custom to do) under one title, that from very early days the two processes of work were used together.'...