THE ANALYST. 247 REVIEWS. THE CYANIDE INDUSTRY. By R. ROBINE and M. LENGLEN. Translated by J. ARTHUR With an Appendix by C. E. MUNROE, PH.D. (New York: London : Chapman and Hall, 1906. The manufacture and utilization of cyanogen compounds have undergone rapid development in recent years, and the work under review is an attempt to classify the various methods employed at the present time. The book comprises four sub- divisions, the first of these dealing with the chemical reactions involved, together with the preparation and properties of the more important single and double cyanides. Part 11. is practically a directory of the works at which the cyanide industry is carried on, whilst Part 111. is devoted to the manufacturing processes in general use. LECLERC, PH.D. Wiley and Sons.Price 17s. net.)248 THE ANALYST, The commercial application of the different cyanogen compounds is discussed in the last section, and an appendix contains a digest of the United States patents relating to the recovery of precious metals by means of cyanides. The descriptive matter as a rule is concise, and the processes of manufacture are clearly explained. The authors point out that the application of cyanides to the treatment of auriferous materials is the immediate cause of the progress realized by the industry during the last fifteen years, whilst the discovery of cyanide compounds in the bye-products of the manufacture of illuminating gas has also widened the field of investigation towards synthetic processes. I n the small space allotted in the book to analytical properties the usual tests for cyanides are included, but the information given in reference to quantitative deter- minations is rather meagre. Although the book will probably prove useful to the manufacturer as a r&sum& of the ordinary methods employed in the production of cyanides, its value to the analytical chemist is somewhat problematical.P. A. E. R. LES INDUWRIES DE LA CONSERVATION DES ALIXENTS (The Food-preserving Industry). This book is divided into seven chapters, respectively treating of historical sketch, the causes and effects of changes due to putrefaction, preservation by heat, by cold, by desiccation, by antiseptics, and by the prevention of the entrance of micro-organisms into such naturally sterile products as eggs.There is little or no analytical information, the whole subject being treated of from a technical point of view ; but the work is well up to date, and gives a fairly complete description of the various methods of food preservation. As is natural in a French work, the processes and details of packing and transport are chiefly those used in France, but these are fairly typical, and in most cases will give the food analyst a good general idea of the technology of the food-preserving industry. One passage taken from the report of Dr. Bordas, adopted by the Congress of Hygiene, is worth quoting in extenso .- (‘ En r6sum6, l’addition d’antiseptiques dans les denrdes alimentaires produit les resultats suivants : ‘* 1. Elle est susceptible de nuire A la sante. ‘* 2. Elle peut perrnettre de conserver des &l&ments ayant d&j& subi un ‘( 3. Elle modifie le plus souvent la composition des 6ldments organiques. L L I1 y a lieu d’interdire l’emploi des antiseptiques quels pztils soient, noc$s ou non, dans toutes les matibi*es alimentaires.” H. D. R. By X. ROCQUES. (Paris, 1906. . Pp. xii+506. Price 15 francs.) commencement d’alt &ration.