1) R. A. HAUSTEN. Light and Colors. Translation edited by Prof. N. P. Kasterin. GIZ, Moscow—Leningrad, 1926, pp. VIII + 196. Price 1 rub. 80 kopecks.

2) W. OSTWALD. Color Science. Translation by Z. O. Milman, edited and with a preface by S. V. Kravkov. Promizdat, 1926, 204 pp.

3) L. RICHTER. Fundamentals of the Theory of Colors. Translation and additions by Prof. N. G. Fedorov. GIZ, Moscow—Leningrad, 1927, 136 pp. Price 1 rub. 40 kopecks.

The main subject of the books named is the subjective sensations of light and colors and, strictly speaking, their relation to the physical sciences is very remote, like that of counterpoint to physical acoustics. But historically the theory of colors was created by physicists. Having discovered the chief object of physical optics—the monochromatic ray—Newton at the same time laid the foundation for subjective “color science.” The psychological laws of colors were studied by Lambert, Helmholtz, Maxwell, and in our time by Schrödinger, Schaefer, and many other physicists. Therefore, even if the theory of colors has essentially nothing in common with physics, it bears obvious traces of a “physico-mathematical style” and has always keenly interested, and continues to interest, precisely physicists. This science, resting on the foundations of physics, physiology, and psychology, has acquired direct and quite real significance for industrial coloristics, painting, lighting technology, and other practical fields. Three translated books on the subject of colors, which appeared almost simultaneously, are not competitors with one another; they differ in character and aims and very successfully complement one another.

1) Hausten’s book speaks very substantially, vividly, and wittily about a great many things. It is not a monograph, not a textbook, but a highly engaging book for reading, intended for a wide circle of persons interested in practical optics: physicians, photographers, artists, architects, illuminating engineers, etc. The exposition is quite simple, but we are confident that every specialist physicist will find on the pages of Hausten’s book much that is new and useful for himself as well. It is impossible even schematically to outline the main lines of this lively book.

it is as though it were deliberately written without any plan. The first third of the book is, to some extent, devoted to pure optics: here the nature of light is discussed, the fundamental optical phenomena, the boundaries of the spectrum, and so on. The reader will find here everything “from A to Z,” from Newton’s experiments with a prism to the deflection of light rays in a gravitational field. But this is not an outline of a course in optics, but rather, so to speak, a series of snapshot photographs giving a very vivid impression of the subject. The central part of the book—at least in the mathematical sense—is the theory of colors, the elements of physiological optics and various applications (color photography, questions of economy in illumination, etc.). Next comes a discussion of practical photochemistry and phototherapy, illustrated with unconventional biological examples. The book ends with a chapter on the psychology of color. The text is somewhat abridged in comparison with the original; the Russian edition is considerably more modest than the English one, and we cannot agree with the statement in the text that “the reproduction of the solar spectrum on the color plate is more beautiful than Newton saw it.” We very much recommend that everyone who is not indifferent to questions of optics, from school pupil to professor of physics, become acquainted with Houston’s book.

2) Ostwald’s books on colors have been appearing in an uninterrupted series over the last decade, probably in response to very great demand. Many of them are variations on one and the same theme. For the Russian translation there has evidently been chosen Ostwald’s most detailed work (Farbkunde, 1923). In the translation this Ostwaldian neologism is very successfully rendered by the term “color science,” which, we hope, will take root in Russian literature.

Ostwald’s monograph is, to a certain degree, a rather dangerous book. It is written extremely simply, is intended for and will be understood by very many people. Its exposition is interesting and at times entertaining, while the author’s great authority aggravates the seeming canonical character of his assertions. Meanwhile, much in Ostwald’s teaching (and especially in his methods of measurement) can be accepted only with great reservations and in any case must not lay claim to precision.

In the preface by the editor of the Russian translation there is given a detailed survey of the criticism of Ostwald’s views. Unfortunately, the survey is somewhat in the form of notes and in many places will scarcely be within the powers of the reader who has fully mastered the contents of the book itself.

Ostwald’s principal and great merit is that he introduced a natural rational gradation of gray and chromatic “light-clear” and “dark-clear” tones, based on the psychological law of Weber–Fechner. Ostwald’s color circle had been proposed before, and in particular served as the basis for another American classification of colors, developed by Munsell, which became widely disseminated in the U.S.A. Munsell’s “color solid,” from the point of view of physiological and mental laws, is more correct than Ostwald’s simple color cone, but in any case both classifications are apparently sufficient for the needs of technology. Ostwald’s color atlas makes it possible to express every color symbolically by two letters and a number, and in this way the practically infinite variety of colors becomes amenable, if not to mathematical analysis, then at last to registration. This circumstance has also been appreciated by technology. But it is still too early to speak of a complete rationalization of the uniformity of color. Apparently, a union of Munsell’s ideas with gradations according to Fechner’s law will lead to a logically ordered, though complex, system for a considerable group of colors.

The Russian translation is somewhat heavy. Ostwald’s constant word-formation, natural in the German language, forces the Russian translation to resort to cumbersome and lifeless words such as “mediated” (vermittelte), “unrelated” (unbezogen), “influentiality” (Ausgiebigkeit), “givenness,” etc. Perhaps, at some loss of precision but with a gain in readability, in the next edition of this book, intended for the broadest circle of readers, it would be better to replace such terms with more Russian words?

There are also errors (or misprints) in the translation, for example, “vertical” instead of “horizontal” (p. 34), “abbreviated” instead of “reduced” (p. 119). The book is printed very “blindly,” and in an edition devoted to vision and color one would like to see a certain concern on the publisher’s part for the reader’s visual hygiene. The color plates, executed by the Turkin method, are good.

3) Unlike the first two books, Richter’s little book is not a book for reading and not a monograph, but an excellent small textbook intended for art and textile schools. It contains, to an extremely moderate extent, precise data from optics and the physiology of the eye, but the main part is concentrated on the study of color.

The translator’s additions in the text and notes detail particular questions. In particular, Ostwald’s doctrine is set forth in 7 pages, and everything essential and practically necessary is indicated.

In the chapter on the chemistry of paints the translators have made certain additions concerning methods of recognizing paints and identifying pictures by new methods. Only minimal knowledge from the fields of physics, chemistry, and physiology is needed for the study of this textbook; the book is read very easily, is published clearly and pleasantly.

S. Vavilov.