Book excerpt: Presenting far-reaching new therapeutic research, Peter Gruenewald examines the underlying spiritual aspects of constitutional treatment using medicines derived from the mineral kingdom. This constitutional approach is used in the treatment of chronic physical, neurological, developmental, emotional, behavioral, and mental conditions and illnesses, It centers on a system of nine minerals. Gruenewald traces these nine substances on their paths through the human organism and demonstrates their indications, effects, and interactions. He also develops a spiritual and alchemistic understanding of the actions of these substances, based on anthroposophic medical research. Gold, the sun metal, and carbon, the substance of organic life on Earth, occupy a central position in this study of the mineral system. The Philosopher's Stone is achieved through the "transformation of carbon" and the "creation of gold." The author shows how the important medicine Aurum (made from gold) relates to this process. He suggests that mineral therapy focused on the principle of transformation conceals future spiritual mysteries that relate to evolutionary laws inherent in the physical and higher bodies.