An "Alchemist" is a historical figure who practiced alchemy, a philosophical and proto-scientific tradition that aimed to transform base metals into noble metals like gold. Alchemists sought to discover the Philosopher's Stone, a legendary substance believed to grant immortality and turn lead into gold. They combined elements of chemistry, metallurgy, medicine, and mysticism in their experiments. Alchemists were active from ancient times through the Middle Ages and into the Renaissance. Their work laid the groundwork for modern chemistry, as they developed laboratory techniques and equipment. Although their goals were often mystical, their contributions to science and the understanding of materials were significant in shaping future scientific inquiry.