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Jap Baptista van Helmont
Van Helmont performed a 5-year experiment involving a willow tree which he planted in a pot with soil and placed in a controlled environment and carefully and precisely watered over the 5 year period. At the end, Helmont concluded that the growth of the tree was due to the nutrients in the water, not the soil. The conclusion was inaccurate but the experiment proved that water contributes to the growth of plants. -
Joseph Priestly
Conducted an experiment which included placing a lit candle inside a closed jar. the flame quickly went out and priestly concluded that the flame had been injured. although he did not know at the time, his experiments proved that air contains oxygen. -
Jan Ingenhousz
Ingenhousz placed submerged plants in sunlight and then in shade. he noticed that small bubbles were produced by the plants when they were in the sunlight contrary to when it was in the shade where no bubbles were produced. Ingenhouz later concluded that plants use light to produce oxygen. -
Jean Senebier
Demonstrated that plants absorb carbon dioxide and release oxygen with the help of sunlight. In the early 1800s Nicolas-Theodore de Saussure demonstrated that while plants need carbon dioxide, the increased mass of growing plants is not the result of carbon dioxide alone but also the uptake of water. -
Julius Robert Mayer
Stated that energy can be neither created nor destroyed, known as the first law of thermodynamics. He proposed that plants convert light energy into chemical energy -
Period: to
General Equation, Julius Von Sachs
Investigated how starch is produced under the influence of light and in relation to chlorophyll. in the 1930s Cornelis Van Niel proposed the general equation for photosynthesis:
CO2 +2H2A + light energy --> [CH20] + 2A +H20