As a surgeon to the Roman legions of Emperor Claudius in the first century, the author Dioscorides had plenty of opportunity to travel and catalogue substances used in treating illnesses and wounds. His text De materia medica looks at the medical uses of more than 1,000 plant and animal products, wines and minerals. He rejected alphabetical ordering and chose to classify the material as animal, vegetable and mineral. This picture of Dioscorides comes from the facsimile edition of the superbly illustrated medieval text Medicina Antiqua (Harvey Miller, £48, $75). As Peter Murray Jones points out in his introduction to this edition, Dioscorides was credited in medieval times as the innovator of illustrated materia medica.