The study of the roles of metal ions in biological systems represents the exciting and rapidly growing interface between inorganic chemistry and the living world. Metals play a crucial catalytic role in many enzymes, in electron transfer in respiration and photosynthesis, as well as in oxygen production in the latter. Yet many metals like cadmium and mercury are toxic, while others like platinum and gadlinium are used in therapeutic and diagnostic applications. This new book, written by a biochemist in an agreeable and relaxed style gives an excellent overview and introduction to this fascinating area.