Blurb:

The trade in artists’ materials, and their purification, synthesis and preparation provided clues about the values they embodied. But those clues all came from their outer nature, and things have an inner nature too. Lapis, for example, is the embodiment of water – which is why it lowered fevers, cleansed the eye and treated snake-bites – yet it contained a hidden germ of fire. Having looked at the outer nature of artists’ materials, the rest of this book deals with their inner nature. Of course, like ultramarine’s fire, the inner nature of things can be hidden, so this chapter explores how to see the inner nature of a colour.