Changes in Illuminated Manuscripts

Before commenting on some of the lessons to be drawn from individual pictures, it may be desirable to make a few observations on some of the changes frequently observable in old illuminated manuscripts and choral books. The tarnishing of lead and copper pigments laid on without any protection but that of gum is very frequently seen. The darkening of vermilion is apparently capricious,¹ but is really explicable in part by the substitution of red lead for vermilion, and in part by the molecular change which the latter pigment is known to suffer, and which has been already described. Ultramarine always stands out absolutely intact; sometimes it acquires extraordinary prominence by reason of every other pigment on a page having altered. The red cochineal and kermes lakes have either gone or become paler and brownish. Sometimes fruits painted in vermilion have been shaded or dotted with a crimson lake, but the latter has disappeared, leaving nothing but a slight gummy appearance upon the scarlet ground. Blue flowers painted in smalt and veined with indigo show scarcely a trace of the latter pigment. Verdigris, which is partly soluble in water, has run and discoloured the vellum, and at the same time has acquired a brownish hue. Sap-green, from buckthorn berries, has faded greatly. Lilien-grün (of the seventeenth century), from the flowers of Iris germanica, has disappeared.

1	An initial letter in vermilion, painted in the fifteenth century, and perfectly unchanged, became black by one year's exposure to sunshine.