"Coloration may also be due to a process of tincture or dyeing, when one thing takes its hue from another. Common sources of such coloration are the flowers of plants and their roots, bark, wood, leaves, or fruit, and again, earth, foam, and metallic inks. Sometimes coloration is due to animal juices (e.g. the juice of the purple-fish, with which clothes are dyed violet), in other cases to wine, or smoke, or lye mixture, or to sea-water... In short, anything that has a colour of its own may transfer that colour to other things, and ...colour leaving one object passes with moisture and heat into the pores of another... Furthermore, steeping material to be dyed in different astringent solutions during the dyeing produces a great variety of hues and mixtures, and these are also affected by the condition of the material itself..."