The editors of a scientific journal have compiled selected articles into a book to broaden its readership. The book is divided into twelve chapters covering various scientific fields, including astronomy, geophysics, genetics, and more. The quality of the book is high, with clear and insightful writing. However, it lacks references to recent developments in chemotherapy, electronics, and metallurgy, which are important for a general audience. The book also focuses mainly on American research, missing international contributions. Despite this, it includes notable chapters by experts like George Gamow and Walter Bucher. The book contains useful diagrams and explanations. The second part of the text discusses the "Chemistry of Heterocyclic Compounds," a series of monographs. The series aims to address the lack of comprehensive literature in heterocyclic chemistry. The two volumes reviewed are the fifth and sixth in the series. Dr. Simpson's volume covers cinnolines, phthalazines, and quinoxalines, with detailed information on their chemistry up to 1949. The section on quinoxalines omits references prior to 1917, but this does not affect the clarity of the content. Prof. Hofmann's volume on imidazoles includes a review of fundamental imidazole chemistry, synthetic methods, and reactions. It also includes a catalog of compounds and references. Both volumes are well-illustrated and well-produced, with useful indexes. While the second volume could benefit from a less-encumbered text, it is overall a valuable resource for organic chemists.The editors of a scientific journal have compiled selected articles into a book to broaden its readership. The book is divided into twelve chapters covering various scientific fields, including astronomy, geophysics, genetics, and more. The quality of the book is high, with clear and insightful writing. However, it lacks references to recent developments in chemotherapy, electronics, and metallurgy, which are important for a general audience. The book also focuses mainly on American research, missing international contributions. Despite this, it includes notable chapters by experts like George Gamow and Walter Bucher. The book contains useful diagrams and explanations. The second part of the text discusses the "Chemistry of Heterocyclic Compounds," a series of monographs. The series aims to address the lack of comprehensive literature in heterocyclic chemistry. The two volumes reviewed are the fifth and sixth in the series. Dr. Simpson's volume covers cinnolines, phthalazines, and quinoxalines, with detailed information on their chemistry up to 1949. The section on quinoxalines omits references prior to 1917, but this does not affect the clarity of the content. Prof. Hofmann's volume on imidazoles includes a review of fundamental imidazole chemistry, synthetic methods, and reactions. It also includes a catalog of compounds and references. Both volumes are well-illustrated and well-produced, with useful indexes. While the second volume could benefit from a less-encumbered text, it is overall a valuable resource for organic chemists.