Name the scientist, who first pointed out that plants purify foul air
by bell jar experiment.

Options

A. Willstatter
B. Robert Hooke
C. Priestley
D. Iean Senebier

Answer

**Step-by-Step Solution:**

1. **Identify the Scientist**: The question asks for the name of the scientist who first demonstrated that plants can purify foul air through an experiment known as the bell jar experiment.

2. **Recall the Bell Jar Experiment**: The bell jar experiment was conducted to observe the effects of plants on air quality. In this experiment, Joseph Priestley placed a burning candle and a mouse in a sealed environment (the bell jar).

3. **Describe the Experiment**:
- Initially, when the candle was lit inside the bell jar, it burned for a while but eventually extinguished due to lack of oxygen.
- The mouse, when placed in the bell jar, suffocated and died because the air was not suitable for breathing after the candle had burned.

4. **Introduce the Mint Plant**: Joseph Priestley then introduced a mint plant into the bell jar. After some time, he observed that the mouse was able to survive and the candle could burn again.

5. **Conclusion from the Experiment**: Priestley concluded that the mint plant was able to purify the foul air, which was contaminated by the burning candle and the respiration of the mouse. This led him to hypothesize that plants could restore the air quality.

6. **Final Answer**: The scientist who first pointed out that plants purify foul air by the bell jar experiment is **Joseph Priestley**.