Explain Joseph-Priestly's experiments on photosynthesis using candle and a plant.

Explanation

(a) Priestly performed an experiment to reveal the essential role of air in the growth of green plants.
(b) Priestly -observed that a candle burning in a closed space - a bell jar soon gets extinguished.
(c) Similarly a mouse would soon suffocate in a closed space.
(d) He concluded that a burning candle or an animal that breathe the air, both somehow damage the air.
(e) But when he placed a mint plant in the same bell jar he found that the mouse stayed alive and the candle continued to burn. He concluded that plants restore the air whatever breathing animals and burning candles remove.