Originally published in the Soviet Union, this book is a study aid for students of chemical and metallurgical departments of polytechnical colleges and technical schools. It describes the theoretical principles and practical procedures of present-day physicochemical methods of analysis. A great deal of attention is devoted to activation analysis, mass-spectrometric analysis and spectrometry in the infrared. These methods are widely used in cosmic investigations and in studying the structure of the universe. A detailed description is given of equipment and instruments employed at present for physicochemical analysis. The book will be of use to workers of research and plant laboratories. It has seen four Russian editions, and is now presented for the first time in English. The author, Yuri Lyalikov, Professor, Doctor of Chemical Sciences, is a Corresponding Member of the Academy of Sciences of the Moldavian SSR. He is head of a research laboratory of the Academy of Sciences of the Moldavian SSR where he carries on extensive research in the field of electrochemical methods of analysis. Yuri Lyalikov is the author of a large number of papers, scientific works and textbooks on questions of physicochemical analysis. The most popular of them are: Analysis of Iron and Manganese Ores and Physicochemical Analysis. Besides his research, Yuri Lyalikov carries on pedagogical work. He is a professor of the Chair of Analytical Chemistry at the Kishenev State University.