Experimental plant of J. Priestley is

In the 1770s, Joseph Priestley conducted experiments and observed that a burning candle or a breathing animal consumed the "vital air" (oxygen) in a closed space, leading to the extinguishing of the candle or suffocation of the animal. However, when he introduced a mint plant into the same space, the mouse remained alive, and the candle continued to burn. From this, he hypothesized that plants restore the "vital air" to the atmosphere, replenishing the oxygen consumed by animals and burning candles. This work laid the foundation for the discovery of oxygen and deepened our understanding of the reciprocal relationship between plants, animals, and the Earth's atmosphere.