1. History of Yttrium and Scandium. 2. Chemical and Physical Properties of Scandium and Yttrium. 3. Analytical Chemistry of Scandium and Yttrium. 4. Occurrence of Scandium and Yttrium in Nature. 5. Occurrence of Scandium and Yttrium in Organisms. 6. Interactions of Scandium and Yttrium with Molecules of Biological Interest. Suggested Further Reading. Index.