2. Phlogiston Theory
During the Enlightenment, many chemists subscribed to the phlogiston theory. They believed a mysterious, fire-like substance called phlogiston was released when things burned. This idea shaped scientific thought for decades, despite mounting evidence against it. It wasn’t until Antoine Lavoisier demonstrated that combustion actually involved oxygen that the theory was finally overturned. For more on this curious chapter in chemistry, see Scientific American.
