We all know that plants cannot live without the sun. Plants around us absorb energy from sunlight to make food from water and carbon dioxide. This process is called photosynthesis. Though this phenomenon has existed since time immemorial, humans were ignorant about it until the 1800s.
When green plants receive sunlight, they consume higher amount of carbon dioxide than they release. Moreover, they give out more oxygen than they take in.
When it is dark, they use oxygen and release carbon dioxide like any other animals and humans.
This process was first described by the Dutch doctor Jan Ingenhousz in 1779 in his book ‘Experiments Upon Vegetables, Discovering Their Great Power of Purifying the Common Air in Sunshine, and of injuring it in the Shade and at Night.’
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