Systematic Identification of Organic Compounds: A Laboratory Manual. By Prof. Ralph L. Shriner and Prof. Reynold C. Fuson. Pp. ix+195. (New York: John Wiley and Sons, Inc.; London: Chapman and Hall, Ltd., 1935.) 11s. net. Interest in organic identification work at the University of Illinois was first sparked by Prof. C. G. Derick in 1908, and the course was developed by Prof. O. Kamm. The present volume is based on a one-semester course with two three-hour laboratory periods per week, now in use at the University of Illinois for students who have had a year of organic chemistry. The book provides a systematic approach to identifying unknown organic compounds, starting with solubility relationships, followed by classification reagents, physical constants, and suitable derivatives. It includes full practical directions and many tables of physical constants. A later chapter deals with the separation of mixtures. The authors have provided a useful manual for a type of work that emphasizes the student's ability for careful observation, correct deduction, and originality in planning. This training provides excellent experience for those preparing for research work in organic chemistry. Industrial Electronics. By F. H. Gulliksen and E. H. Vedder. Pp. xiv+245. (New York: John Wiley and Sons, Inc.; London: Chapman and Hall, Ltd., 1935.) 17s. 6d. net. The book is well worth reading despite its defects. It provides a large amount of detailed information on applications already effected and is stimulatingly suggestive of new applications and developments. However, the compression of information has been carried too far, sacrificing clarity and ease of reading. The book outlines various applications, including light-sensitive controlling, indicating and recording devices, timing devices for welders, rectifiers and inverters, etc. A final and valuable section deals with electronic regulators. Die Blatt-Minen Mittel- und Nord-Europas: Bestimmungs-Tabellen aller von Insekten-Larven der verschiedenen Ordnungen erzeugten Minen. By Prof. Dr. Martin Hering. Lief. 2: Brunella—Filipendula. Pp. 113–224+2 plates. (Neubrandenburg: Gustav Heller; 's-Gravenhage: W. Junk, 1936.) The attention of entomologists and botanists is directed to "Die Blatt-Minen Mittel- und Nord-Europas" (including England) edited by Dr. Martin Hering. It is to be completed in 5-6 parts, each issued at a subscription price of 12 gold marks, and the publishers state that the work will be completed by the middleSystematic Identification of Organic Compounds: A Laboratory Manual. By Prof. Ralph L. Shriner and Prof. Reynold C. Fuson. Pp. ix+195. (New York: John Wiley and Sons, Inc.; London: Chapman and Hall, Ltd., 1935.) 11s. net. Interest in organic identification work at the University of Illinois was first sparked by Prof. C. G. Derick in 1908, and the course was developed by Prof. O. Kamm. The present volume is based on a one-semester course with two three-hour laboratory periods per week, now in use at the University of Illinois for students who have had a year of organic chemistry. The book provides a systematic approach to identifying unknown organic compounds, starting with solubility relationships, followed by classification reagents, physical constants, and suitable derivatives. It includes full practical directions and many tables of physical constants. A later chapter deals with the separation of mixtures. The authors have provided a useful manual for a type of work that emphasizes the student's ability for careful observation, correct deduction, and originality in planning. This training provides excellent experience for those preparing for research work in organic chemistry. Industrial Electronics. By F. H. Gulliksen and E. H. Vedder. Pp. xiv+245. (New York: John Wiley and Sons, Inc.; London: Chapman and Hall, Ltd., 1935.) 17s. 6d. net. The book is well worth reading despite its defects. It provides a large amount of detailed information on applications already effected and is stimulatingly suggestive of new applications and developments. However, the compression of information has been carried too far, sacrificing clarity and ease of reading. The book outlines various applications, including light-sensitive controlling, indicating and recording devices, timing devices for welders, rectifiers and inverters, etc. A final and valuable section deals with electronic regulators. Die Blatt-Minen Mittel- und Nord-Europas: Bestimmungs-Tabellen aller von Insekten-Larven der verschiedenen Ordnungen erzeugten Minen. By Prof. Dr. Martin Hering. Lief. 2: Brunella—Filipendula. Pp. 113–224+2 plates. (Neubrandenburg: Gustav Heller; 's-Gravenhage: W. Junk, 1936.) The attention of entomologists and botanists is directed to "Die Blatt-Minen Mittel- und Nord-Europas" (including England) edited by Dr. Martin Hering. It is to be completed in 5-6 parts, each issued at a subscription price of 12 gold marks, and the publishers state that the work will be completed by the middle