Question

Can you imagine how priestly would have conducted the experiment using a candle and a plant? Remember he would need to rekindle the candle to test whether it burns after a few days. How many different ways can you think of to light the candle without disturbing the set up?

Answer 1

Joseph Priestley performed a series of experiments that exposed the essential role of air in the growth of green plants. He observed that a candle burning in a closed space gets extinguished following some time.

Complete answer:
In 1771 and 1772, Joseph Priestley performed a series of experiments that discovered the essential role of air in the growth of green plants. Priestley observed that a candle flaming in a clogged space such as a bell jar, soon gets extinguished.

In August 1771 Joseph Priestley, positioned a mint plant into a transparent stopped space with a candle that burned out the air until it rapidly went out. After 27 days, he relit the extinguished candle once more. In view of the fact that there was no bright source of light existing that time, Priestly had to rely on the sun. He focused sunlight beams with a mirror onto the candle wick and was successful in relighting the candle from exterior the bell jar without disturbing the experimental setup.

We can use more sophisticated methods to light the candle like focusing light from a flood light through a converging lens, or by an electrical spark. Later, he placed a plant into a transparent closed space with a candle that burned out the air until it extinguished. However, after a few days, he rekindled the candle again. At that time, he relied on the sunlight. He focused sunlight beams with a mirror onto the candle wick. There are dissimilar ways to light the candle without disturbing the experimental set up by focusing a light from side to side converging the lens or by an electrical spark.

Note:
i) Priestly conducted experiments to find out the importance of air for the growth of green plants.
ii) He placed a burning candle and a mouse in a bell jar.
iii) He observed that mouse died of suffocation,
iv) He concluded that animals that breathe air or a burning candle damaged the air in some way. Green plants will restore the air what else the burning candle or breathing animals gives out.