Early Experiments of Photosynthesis



Introduction to the history of photosynthesis

There are the scientists who explained the life-sustaining process, photosynthesis.
  • Aristotle: Over two thousand years ago, he said that plant absorbs all the inorganic and organic material directly from the soil.
  • Jan Baptista Von Helmont: In the year 1648, he conducted an experiment. In this experiment, He grew a weighed mass of willow tree in a pot with the weighed amount of soil. He covered the soil with the lid with small the small hole. The lid allows only rainwater to pass. After five years, he discovered that the mass of the tree and soil more than it did at the start. He concluded that major substance for plant growth is water.
  • Stephan Hales: He described that plant exchanges gases with the surroundings.
  • Priestley: He demonstrates that plant has the ability to reserve air.
  • Igenhouz: He discovered that plants has the ability use carbon dioxide only in the presence of sunlight.


Recall the history of photosynthesis

Many scientists have contributed to understanding how plants carry out photosynthesis. These are as follows:
1. Van Helmont (1648) concluded that all food of the plant is derived from water and not from the soil.
2. Stephen Hales (Father of Plant Physiology) (1727) reported that plants obtain a part of their nutrition from air and light may also play a role in this process.
3. Joseph Priestley (1772) demonstrated that green plants purify the foul air (i.e., Phlogiston), produced by burning of the candle, and convert it into the pure air (i.e., Dephlogiston).
4. Jan Ingen-Housz (1779) concluded by his experiment that purification of air was done by green parts of the plant only and that too in the presence of sunlight. Green leaves and stalks liberate dephlogisticated air during sunlight and phlogisticated air during dark.
5. Jean Senebier (1782) proved that plants absorb CO and release O in presence of light. He also showed that the rate of O evolution depends upon the rate of CO consumption.
6. Lavoisier (1783) identified the pure air (i.e., phlogiston) as oxygen (O) and noxious air (i.e., Phlogiston) produced by the burning of the candle as carbon dioxide (CO).
7. Nicolas de Saussure (1804) showed the importance of water in the process of photosynthesis. He further showed that the amount of CO absorbed is equal to the amount of O released.
8. Pelletier and Caventou (1818) discovered chlorophyll. It could be separated from the leaf by boiling in alcohol.
9. Sachs (1864) discovered the carbohydrate as a product of the photosynthesis.
10. Emerson and Arnold (1932) described the occurrence of light and dark reaction during the process of photosynthesis.
11. Robert Hill (1937) demonstrated the photolysis of water in light reaction of photosynthesis.