The early experiment by Van Helmont (1600s) describes how he grew a tree in a large pot and found that after five years, the amount of soil in the pot had not changed. He concluded that the increase in weight was due to the addition of water. At that time, the compounds in air had not yet been identified. Today, you know that he only discovered half the story. Requried:
Which additional experiment would provide evidence for the rest of the story?