What was van helmont's hypothesis?

Oh, dude, Van Helmont's hypothesis was that plants gain their mass from water, not soil as previously believed. He did this by conducting an experiment where he planted a willow tree in a measured amount of soil and watered it for five years. At the end of the experiment, he found the tree had gained a significant amount of mass, leading him to conclude that water was the main source of a plant's growth. Like, who knew water was the real MVP for plants, right?