91Ó°ÊÓ

Jan Baptista van Helmont was a Dutch physiologist as well as a chemist. He was born in 1580 and he was the founder of pneumatic chemistry. He introduced the term ‘gas’ into science.

Helmont experimented on a willow tree which is considered as one of the earliest quantitative experimental studies on plant growth and nutrition in the history of biology.

Helmont grew a tree named Willow tree and he measured the weight of the tree and the amount of soil. After four to five years, he again measured the weight of the tree and found that the weight has increased but the amount of soil is still the same.

Hence, he showed that plants do not consume soil to grow and gain weight, which is correct. He also suggested that plant growth and weight gain are due to the intake of water.