THE author of this book is a skilled pathologist, and, therefore, necessarily a practical master of the manipulation of a microscope, at least in the case of transparent objects. He has probably arrived at his views on the microscope by prolonged and varied practice, and by independent thought, rather than by studying the work of others. He thinks the reader may find a grievance in the number of newly-coined words which he employs; but in a special subject no one should object to technical terms, without which science would indeed involve circumlocution, so long as a new technical term is carefully defined. The Principles of Microscopy; a Handbook to the Microscope. By Sir A. E. Wright Pp. xxii + 250. (London: Archibald Constable and Co., Ltd., 1906.) Price 21s. net.