THE ever-growing output of research that Tmarks the progress of chemical science is reflected in the increasing size of the chemical journals; and the task of the researcher whose text-books these form becomes more onerous each year. The work is lightened by the publication of the Chemical Society's Annual Reports, and by the appearance from time to time of monographs dealing with the more important theoretical aspects of the problems under investigation, but the wealth of information 'tied up' in the experimental work of the original papers is not so easily rendered accessible. This difficulty has been partially solved by the compilation of such comprehensive treatises as Houben-Weyl's " Die Methoden der organischen Chemie," or Meyer's " Analyse und Konstitutionsermittlung organischer Verbindungen," and the first two of the three books under review are frank attempts on the part of the authors to provide for Englishspeaking chemists similar correlated information on definite problems connected with laboratory practice. (1) Mr. Bate seeks to give in a short and concise form the various methods available for the synthesis of organic compounds that may be of utility both to senior students and research chemists, and the present pioneer volume is concerned with the synthesis of derivatives of benzene. The subject is discussed in twelve chapters, each dealing, usually, with one type of reaction. Thus in the chapter on nitro compounds, the nitration of different types of compounds by means of nitric acid is described; then follows a description of other methods of nitration; of the conversion of amines into nitro compounds; of anomalous cases occurring in nitration; and finally, the effect on certain groups of the presence of the nitro group in the molecule is discussed. The text contains full references to the original papers and patents up to April 1925, as in very few cases is sufficient detail supplied to make the reader independent of the original memoir. The reviewer suggests that in a future edition the names of the investigators be given as well as the references, in order to facilitate cross reference to abstract journals; and also, that the present scanty index be considerably extended.The general arrangement of the book is excellent, the printing clear, and the text remarkably free from errors, but in a few cases confusion arises from the use of italics at the beginning of a paragraph for the introduction of a new main section, whilst a sub-section is placed under headlines in heavy type. Not a few formulae are faulty owing to the misuse of the dot and bracket; and the printing of such expressions as " to react the substance," and " the substance to be amidated," and " oxy " for " hydroxy," are not pleasing to the English ear. These minor blemishes do not detract from the value of a book of such excellence that it should form a unique and most useful addition to the reference library of the organic chemistry departments of all university and technical institutions. (2) Prof. MacArdle's book is the first part of a treatise on the operative technique of synthetic organic chemistry, similar in a general way to the first sections of the well-known German works of Lassar-Cohn and of Weyl. The first chapter is devoted to " General Considerations," and treats of solution, methods of bringing about solution, choice of solvent, interliquefaction, crystallisation, solvent of crystallisation, and mixed crystals. In the following seven chapters the uses of the various types of solvents are discussed, the question of the purifying of the substance being treated critically and the fullest practical details being supplied. These chapters are rich in references to special cases in which the solvent in question has proved of unique value, and also of instances when anomalous reactions have occurred which limit the use of the solvent. The remaining two chapters are devoted to a consideration of "Special Means to Induce Crystallisation " and to "Salting Out "; a full bibliography and two exhaustive indexes are appended.The arrangement of the book and the presentation of the subject leave nothing to be desired; for, in addition to its eminently practical value, the book is a readable one and holds the interest of the reader from the first page to the last. The statement on page 138 that the dangers attending the use of dimethyl sulphate have been very much exaggerated cannot be generally endorsed, for in the experience of the reviewer more than one case of serious and prolonged indisposition has resulted from the use of this substance without special precautions being taken to remove all vapours in an effective draught.(3) The last of the three books with which this review is concerned differs widely in scope and purpose from the others. It is the fifth volume of " An Annual Publication of Satisfactory Methods for the Preparation of Organic Chemicals "; and indeed so eminently satisfactory are the methods described therein that the issue of the yearly volume marks a red letter day in the organic laboratory. Since the publication of the first volume, when the editors invited the co-operation of other organic chemists, the response has become wider each year, and in this volume twenty-four of the thirty-three preparations have been submitted by eighteen contributors.