The bridge between alchemy and chemistry was crossed when scientists tried to answer the question: “Why do things burn?”. Starting from the perspective of four elements and arriving at the discovery of oxygen, this 100 year journey is a brilliant showcase of the difference between pseudoscience and science. Why do some materials burn and others don’t? How can we explain why things cease burning? To answer these questions scientists assumed that there was a material substance that left the material while burning. To learn about how this substance could help explain combustion and what hydrogen has to do with it, listen to this week’s episode of Good in Theory.