[...]the coruscant scalings in a mortar, I screened them from time to time, carefully ting the gradations of colour-ranging from soft fawn to scintillant saffron-as the more indurated particles stood out the longer against the friction of the pestle. At this time, I might explain, I was in the tentative stage of my experimentation to evolve and perfect a greater variety of media than had hitherto been available with which to express in colour the interminable moods[...].