8: Phlogiston

What? You've never heard of phlogiston? Well, don't beat yourself up about it, because it's not real.

Phlogiston, proposed in 1667 by Johann Joachim Becher, was another element to add to the list (earth, water, air, fire and sometimes ether); it wasn't fire itself, but the stuff fire was made of. All combustible objects contained this stuff, Becher insisted, and they released it when they burned.

Scientists bought into the theory and used it to explain a few things about fire and burning: why things burned out (must have run out of phlogiston), why fire needed air to burn (air must absorb phlogiston), why we breathe (to get rid of phlogiston in the body).

Today, we know that we breathe to get oxygen to support cellular respiration, that objects need oxygen (or an oxidizing agent) to burn and that phlogiston just doesn't exist.

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