‘Alchemy’ refers to a set of practices found in ancient Greece, Egypt and China, and which became particularly influential in Christian, Islamic and Hindu traditions during the Middle Ages. The practitioners of alchemy, known as alchemists, taught that earthly substances were controlled by supernatural powers, and attempted to create new metallic and natural compounds by mixing existing elements together. They often did so in order to try and create valuable substances such as gold or silver, but also attempted to develop medicines.
Islamic alchemists such as Jabir ibn Hayyan (721-815 CE) developed techniques such as distillation and filtration and investigated the medicinal properties of natural objects. These techniques were later influential in medieval Europe, where alchemists such as Ramon Lull (1235-1315) described how certain minerals could be used as drugs. Alchemy provided a bridge between popular and elite medicine throughout this period.
Folk healers used plant compounds to treat disease, and similar techniques were taught in medieval universities. Alchemy was later promoted by the Swiss physician Paracelsus (1493-1541), who was dismissive of the traditional Galenic view that disease could be treated by restoring the natural balance of bodily elements.
From the 1600s the skills developed and promoted by alchemists became increasingly central to medicine, as medical societies published manuals that listed chemical remedies. Alchemy gradually lost its influence because of the spread of modern chemistry in the 1700s - which relied on alchemical techniques, but lost its divine or supernatural basis.
L I Conrad, M Neve, V Nutton and R Porter, The Western Medical Tradition, 800 BC – 1800 AD (Cambridge: Cambridge University Press, 1995)
R Porter, The Greatest Benefit to Mankind: A Medical History of Humanity from Antiquity to the Present (London: HarperCollins, 1997)