The fundamental problem in chemistry is transmutation. How can two homogeneous stuffs with very different properties merge to form another homogeneous material whose properties are different from the reactants? ‘The analysis of stuff’ outlines the history of chemical analysis beginning in the early 16th century with Paracelsus, a deeply religious practising doctor who began to work with chemical remedies rather than those based on plants. The iatrochemistry movement promoted by Paracelsians meant that chemistry became part of the European medical curriculum. Other key characters in the chemical revolution are also discussed—Joan Baptista van Helmont, Daniel Sennert, and Robert Boyle—along with the documentation of elements by Antoine Lavoisier and Isaac Newton.