Lawrence Principe: Alchemy

Science colloquium by Larry Principe from JHU - professor in both chemistry and history of science departments. His principal argument is that alchemy is the legitimate forerunner to chemistry and alchemists have received an unfairly bad press. Many alchemists were extremely careful, observant, and dedicated experimenters. He showed pages from one alchemists lab notebook which looked similar to modern lab notebooks in the way that hypotheses were developed and tested by careful experiments. The idea of changing base metals to gold was based on a theory that all metals were composed of different amounts of philosophical mercury and philosophical sulphur. Study of alchemy is made difficult by the practice of alchemists encoding their public utterances. Fortunately, there are some private letters and notes that provide clues to the codes used. Part of Principe's research has been to decipher formulae for turning base metals into gold and then reproduce the experiments to find out what the alchemists were actually doing. He provided a recent example where the experiment produced a striking dendritic fractal structure looking very like a tree. Principe surmises that this explains the presence of trees in allegorical alchemical illustrations.