The meaning of photosynthesis is light putting together. We know now that photosynthesis is the process plants use to grow, but Aristotle did not know that. He thought plants grew from the ground and that they got everything they needed from the earth.

That theory was believed for many years until 1648. In 1648, Jean Baptiste van Helmont thought that Aristotle was wrong. He decided that he was going to prove it. He put a sapling in a huge pot of earth with a cover over the earth. He watered it and let it grow. After a long while, took the tree and weighed it. It was 169 lbs. while it started at 5 lbs. He also weighed the soil and it was the same weight minus 3oz.

In 1754, Charles Bonnet realized that when a plant is under water, bubbles come up from it.

In 1772, Joseph Priestley did some interesting experiments on...