The Discovery of Photosynthesis

Although photosynthesis has been a process that has occurred since the beginning of time, it was not yet discovered until around the 1600's. Although, like many discoveries in science, the first time it was noticed was not the last time it'd be discovered nor the last time its understanding would be expanded. After the first discovery in the 1600's, it was then further understood in 1771, and again in 1779.

Responsible for the first time photosynthesis was discovered in the 1600's, Jan Baptista van Helmont was carrying out an experiment with a willow tree. Within the experiment, Helmont placed the tree in a pot with soil in a controlled environment. Often, he'd measure the soil and water the plant. By the end of the experiment, the soil weight remained close to the same, but the tree had grown. Helmont concluded that water assists with the growth of plants. This is significant in photosynthesis because water plays a main role in the process and is what the plant uses to make oxygen during it.

At the time, Helmont was unaware of the significance his findings would soon prove to be, but in 1771, Joseph Priestley would help the understanding of the biochemical process of photosynthesis. In his series of experiments, the English chemist was collecting gases that came off when he'd heat a variety of substances in closed jars. In one experiment, Priestly placed a candle and lit it inside a jar, but the flame wouldn't last very long and the air was what he called, injured. Curious to see what the injured air would do to a living thing, he placed a mint leaf inside of the jar and left it for several days. When Priestley came back to the jar, he was pleasantly surprised to find the leaf still green and the air inside to have turned clean again. He considered the leaf to be the reason the air had turned out to be clean but didn't know why. Another experiment Priestley conducted concluded with the same results but involved different variables. In his other experiment, he had plants show their way of transforming the air by first placing a mouse in a jar until it collapsed. Then, he placed the mouse in a jar with a plant and the mice that were placed with the plants survived much easier. Because of his experiments, Priestly proved that plants could be used to change the composition of air.

Furthering the findings of Priestley, a Dutch chemist by the name of Jan Ingenhousz conducted Priestley's experiments again but instead paying close attention to the other factors presented in the experiment. For example, when Ingenhousz redid the experiments for himself, he did some placed in sunlight and some not placed in sunlight. Ingenhousz determined that plants would only transform air when they're placed in sunlight.

Together, Helmont, Priestley, and Ingenhousz all played important roles in discovering the different parts of photosynthesis and relating them back to one another, continuously expanding the knowledge and understanding of photosynthesis itself. Helmont discovered the water component of photosynthesis, Priestley discovered the way plants can transform air, and Ingenhousz discovered the significance of sunlight throughout the photosynthesis process. Science discoveries aren't always fully explained when they're first discovered, it takes many years of hard work and multiple intelligent people to expand ideas and processes to their fullest.

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