The text is in the form of questions to which answers are given at the end of the volume, which comprises one hundred and nine pages. Part First relates to the recognized elements, and Part Second to approximate ratios, temperature, atmospheric pressure and mixed problems, making a compact and useful text-book for the study of chemical problems. * * * * * _Quiz Questions._--Course on Dental Pathological and Therapeutics, Philadelphia Dental College. Prof. J. Foster Flagg, D. D. S. Answered by William C. Foulks, D. D. S. Third edition, Revised and Enlarged. Publishers: The S. S. White Dental Manufacturing Company, Philadelphia, New York, Boston and Chicago. This excellent series of questions and answers on Dental Pathology and Therapeutics is again offered to the dental profession as a work of reference in daily office practice, and is the only book that contains in a condensed and practical form the facts and principles of these subjects, as enunciated by Professor Flagg. Commencing with General Principles, these questions and answers relate to Deciduous Teeth, Pathological Dentition, Lancing, Permanent Teeth, Dental Caries, Sensitive Dentine, Galvanic Action, Pulp Protectors, Obtunding Applications, Pulp Capping, Pathological Conditions of Pulp, Dental Exostosis, Malformed Teeth, Periodontitis and Alveolar Abscess, the whole constituting a work of great value to all engaged in the practice of dentistry. The work is interleaved with blank pages for notes, etc., and gotten up in a neat and excellent style. We take great pleasure in commending this treatise as a valuable adjunct to the regular text-books of the profession. Monthly Summary. PEROXIDE OF HYDROGEN.--_Dr. W. W. Allport, Chicago._--The peroxide of hydrogen (H2 O2), though not a new remedy, has only within the last few years gained much prominence in the treatment of surgical diseases. One of its uses in dental and oral surgery is in blind or deep-seated abscesses, such as arise from roots of diseased teeth. As the tendency of pus is always downward, when these cases occur in the lower jaw it is not infrequent that the abscess, if left to itself, and sometimes even after the tooth is extracted, will point through the external tissues at the lower margin of the jaw, and occasionally downward between the muscles of the neck, and open at various points, even as low down as the clavicle. The usual treatment is to extract the tooth and evacuate the pus through the alveolus, but it often happens that the formation of pus and the continuance of suppuration is not checked, and the abscess points, or is opened through the external tissue of the face or neck, leaving, when healed, a disfiguring scar.