From the contents: Halogens -- Chlorine -- Bromine -- Preparation techniques -- Chloride -- Perchlorate and chlorate -- Organic chlorine -- Bromide -- Organic bromine -- Isotope systematic -- Diffusion -- Membrane filtration -- Ion-exchange -- Equilibrium fractionation -- Perchlorate and chlorate -- Organically bound chlorine and bromine -- Applications.- Stable isotope systematics of the Cl and Br ions -- Cl isotope characteristics of the main reservoirs on Earth -- Interpretation of Cl and Br variations -- Cl isotope characteristics of extraterrestrial material -- Perchlorate and chlorate -- Organically bound chlorine and bromine. This book provides detailed information on the history, analysis and applications of chlorine and bromine isotope geochemistry. Chlorine and bromine are geochemically unique as they prefer to exist as single charged negative ions. For this reason isotope fractionation reflects mostly processes that are not related to changes in the redox state and this fractionation is generally modest. The book will describe the processes that are most easily detected using these isotopes. Also isotope variations, and processes that cause them, measured in oxidised species such as perchlorates and in organic molecules will be described in this book.