Alchemists did more than try to transmute base metals into gold: they studied planetary influences, refined plants and minerals in the search for medicines, and in their search for the elusive philosopher's mercury' they claimed to have found the secrets of the origins of the universe and the regeneration of life The practical and theoretical knowledge of alchemists spread throughout England to influence scientific explanations of the workings of the natural world and the religious mysteries of the Incarnation and Transubstantiation. Alchemical medical theories concerning and Transubstantiation. Alchemical medical theories concerning the quintessence were also adapted for the diagnosis and therapeutic treatment of the illnesses of the body politic and its head the king. Alchemical symbolism focusing on the regenerative and redemptive powers of sulphur and mercury would help to define the kingships of Edward III and Richard II and lay the foundations for the development of alchemy as a source of political symbolism in the fifteenth century. This is the first work to synthesize all aspects of alchemy and show its contribution to intellectual social and political life in the fourteenth century. It explores a rich body of manuscripts to reveal the daily routines of the alchemist and his imaginative mindscape, and considers the contribution of alchemy to the vernacular culture and political debate, leading to a reassessment of the intellectual life of the Middle Ages. Book jacket.