I found that water was essential for the increase of plant mass. Name that scientist.

Explanation

1) A Belgian scientist Jan Baptist Von Helmont (1648) conducted an experiment that continued for five years .
2) Von Helmont took a small willow tree and planted it in a large pot with soil.
3) Before he did this, he carefully measured the mass of the dry soil and mass of the tree.
4) He covered the soil with a lid so that nothing could fall on to the surface of the soil and add to its mass.
5) There were holes in the lid so that the tree could grow out of the soil and that air and water could reach the roots.
6) Von Helmont left the tree for five years, giving it only rain water to absorb.
7) At the end of five years he measured the mass of the tree and the mass of the dry soil for a second time.
8) The results of this expe f iment are shown below .

9) This experiment changed the belief of hundreds of years . This is because Von Helmont arrived at a result that
a) The substances needed for the growth of a plant do not come from the soil only .
b) The plant grow because of the water it gets.