"Devitrification" illustrates the progress made in solving complex problems using the phase rule, with similar studies on silicate mixtures in igneous rocks being conducted successfully at the Geophysical Laboratory in Washington. The chapter on optical properties is of special interest, as optical glass is a key material in civilization and essential for military use. Lens designers have driven the search for suitable glass compositions, leading to specialized glasses, such as those transparent to X-rays and ultraviolet light or opaque to them. Colored glasses that are transparent only to a narrow spectral range are also available. The data on glass's interaction with light is compiled in one chapter, with thirty-six optical glasses from Chance Brothers listed with their properties and compositions. The book's examples show its remarkable thoroughness and are well worth its high price. "Experimental Psychology" by Robert S. Woodworth is a comprehensive survey of the field, addressing the need for a single volume representing current experimental psychology. Woodworth's qualifications and independence from psychological schools allow him to fairly evaluate various experimental approaches. His book is useful and interesting, as it includes only work that genuinely contributes to psychological understanding. While the book is a satisfactory survey, it also highlights ongoing issues in experimental psychology, such as conflicts over facts and poor experimental design. Many experiments lack sufficient subjects and statistical treatment, and raw data is often not published, making it difficult to assess conclusions. However, improvements in experimental standards are expected to enhance future surveys. R. H. Thouless."Devitrification" illustrates the progress made in solving complex problems using the phase rule, with similar studies on silicate mixtures in igneous rocks being conducted successfully at the Geophysical Laboratory in Washington. The chapter on optical properties is of special interest, as optical glass is a key material in civilization and essential for military use. Lens designers have driven the search for suitable glass compositions, leading to specialized glasses, such as those transparent to X-rays and ultraviolet light or opaque to them. Colored glasses that are transparent only to a narrow spectral range are also available. The data on glass's interaction with light is compiled in one chapter, with thirty-six optical glasses from Chance Brothers listed with their properties and compositions. The book's examples show its remarkable thoroughness and are well worth its high price. "Experimental Psychology" by Robert S. Woodworth is a comprehensive survey of the field, addressing the need for a single volume representing current experimental psychology. Woodworth's qualifications and independence from psychological schools allow him to fairly evaluate various experimental approaches. His book is useful and interesting, as it includes only work that genuinely contributes to psychological understanding. While the book is a satisfactory survey, it also highlights ongoing issues in experimental psychology, such as conflicts over facts and poor experimental design. Many experiments lack sufficient subjects and statistical treatment, and raw data is often not published, making it difficult to assess conclusions. However, improvements in experimental standards are expected to enhance future surveys. R. H. Thouless.