Sir Isaac Newton left at his death a large collection of papers on alchemy, mostly in his own handwriting; the importance of this legacy has been debated ever since. When it first appeared, Professor Dobb's detailed analysis of the foundations of Newton's alchemical pursuits further stimulated interest in the subject by firmly establishing the importance of alchemy in Newton's thought. This book sets the foundations of Newton's alchemy in their historical context in Restoration England. It is shown that alchemical modes of thought and particularly those of a Neoplatonic kind, were quite strong in many of those who provided the dynamism for the scientific revolution of the seventeenth century and that these modes of thought had important relationships with general movements for reform in the same period: reform of religion, philosophy, learning, society and of man himself. Newton's alchemy is thus seen as a critical link between Renaissance Hermeticism and the rational chemistry and mechanics of the eighteenth century.