You may discover in the patterns on the wall a resemblance to various landscapes, adorned with mountains, rivers, rocks, trees, plains, wide valleys and hills in varied arrangement; or again you may see battles and figures in action; or strange faces and costumes, and an endless variety of objects, which you could turn into complete and well-drawn forms. The effect produced by these mottled walls is like that of the sound of bells, in which you may recognize any name or word you choose to imagine. . . . It should not be hard for you to look at stains on walls, or the ashes of a fire, or the clouds, or mud, and if you consider them well you will find marvelous new ideas, because the mind is stimulated to new inventions by obscure things.9