Plot: Thirteen building blocks in a science that may be the foundation of the modern world: Joseph Priestly and Antoine Lavoisier's discovery of oxygen, John Dalton's atomic theory, Avogadro's Law, Friedrich Woehler's synthesis of urea, Friedrich Kekule's studies of molecular structure, Dmitry Mendeleyev's Periodic Table, Humphry Davy's electrolysis, J. J