Color is intrinsically a multidisciplinary subject. It cannot easily be confined to a single discipline -just walk into any bookstore and ask where the books on color might be found. Nor it is contained within the intersection of many overlapping disciplines; it pervades all to enliven and enthrall. Starting from an interest in color, one may dip into architecture, physiology, art, engineering, psychology, design, and computing, to name but a few, as readers of this journal know well. "The purest and most thoughtful minds are those which love color the most," said John Ruskin.
Thus, it is a delight to encounter this book by Heinrich Zollinger, a professional dye chemist, to sense his lively interest in color and to see how it leads him across a landscape of such pleasing conformation. His trajectory is not aimless, neither is it fixated on one viewpoint. He takes a path, looks around with curiosity, examines one or two objets trouve Β΄s, then moves off in another direction. The word "approach" in the title is indicative: as the author explains in the Preface, he first describes some facts and then gives a personal interpretation, which may lead to a greater understanding. The result is idiosyncratic but stimulating. Connections are revealed between unexpected things. This is definitely a book to savor and enjoy, while at the same time being erudite. With extensive references at the end of each chapter, it shows the author's wide-ranging study.
Chapter 1 is an eclectic introduction and historical survey. Newton's famous statement, "The rays . . . are not colored," is compared to a saying of Democritus two millennia earlier, "Sweet and bitter, cold and warm, as well as colors, all that exists only as an idea . . ." Chapter 2 presents the physics of light and color, passing effortlessly from Newton's spectrum and Snell's Law of refraction to the Biblical symbolism of the rainbow then to the micro-structure of peacock feathers. In Chapter 3, on the chemistry of color, the author is on home territory and develops from Perkin's mauve through a maze of organic and inorganic dyes, liberally illustrated with molecular structures. Chapter 4 deals with colorimetry, with a mercifully brief description of the CIE system followed by an exploration of hue circles and color harmonies. Chapter 5 covers vision from the structure and photochemistry of the retina through neural pathways to visual psychophysics and finally to color vision in animals, where we learn that both turtles and goldfish are apparently tetrachromatic. Chapter 6 deals with color naming, based on the author's own significant work in this field. The phenomenon of human language leads into color categorization and the influence of culture, following the pio-