Q. Joseph Priestley observed that when mouse alone was placed in a closed bell jar with burning candle, it was suffocated and candle burning extinguished but when mouse was placed with a mint plant in the same bell jar, that mouse stayed alive and candle continued to burn. What he concluded from this experiment?
A) Burning candle remove the air
B) Mint plant restore the air
C) Both (a) and (b)
D) $CO_{2}$ is required for burning of candle
Explanation
Joseph Priestley observed that a candle burning in a closed, a bell jar, soon gets extinguished. Similarly, a mouse would soon suffocate in a closed space. He conclude that a burning candle or an animal that breathe the air, both somehow, damage the air. 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. Priestly hypothesised that plants restore to the air whatever breathing animals and burning candles remove
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.