Q1: 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 kilograms (5 pounds) in a barrel filled with 90 kilograms (200 pounds) of soil and then watered the tree regularly. After five years, the tree had gained almost 75 kilograms (164 pounds), 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?