Page:Arts & Crafts Essays.djvu/232

 composition of the mordant, while the unmordanted parts remain a dirty pink, which has to be "cleared" into white by soaping and exposure to the sun and air; which process both brightens and fixes the dyed parts.

Pliny saw this going on in Egypt, and it puzzled him very much, that a cloth dyed in one colour should come out coloured diversely.

That reminds me to say a word on the fish-dye of the ancients: it was a substantive dye and behaved somewhat as indigo. It was very permanent. The colour was a real purple in the modern sense of the word, i.e. a colour or shades of a colour between red and blue. The real Byzantine books which are written on purple vellum give you some, at least, of its shades. The ancients, you must remember, used words for colours in a way that seems vague to us, because 208