About 200 years ago , Jan Baptista van Helmont wanted to know where growing plants get the materials necessary for increases in size. He planted a tree seedling weighing 2.2 kg(5pounds) of soil and then watered the tree regularly. After 5years, the tree had gained almost 75kgs, and the soil's weight was unchanged. He incorrectly concluded that the tree had gained all of its additional weight by absorbing water. How did the tree really gain most of its weight?