Jan Baptista van Helmont | Belgian scientist | …

However, van Helmont identified water as the sole source of nutrition for the tree.

Jan Baptist van Helmont - Wikipedia

We exhale the carbon dioxide that plants need for photosynthesis.



Many scientists contributed to the discovery and understanding of photosynthesis throughout the ages; in this page are outlined some of those crucial milestone experiments that contributed to this effort.




Jan Baptista van Helmont, Flemish physician, chemist, and physicist, in the 1600s carried out a famous experiment by growing a willow tree in a pot for five years.

18/10/2013 · Jan van Helmont and Joseph Priestly

Van Helmont carried out an experiment to see if the idea from ancient Greece was correct. He grew a willow tree in a weighed amount of soil. After five years, he discovered that the willow tree weighed about 74 kg more than it did at the start. As the weight of the soil had hardly changed, van Helmont concluded that plant growth cannot only be due to minerals from the soil. He thought that the extra plant material had come from the water alone.

Jan Baptist van Helmont (bapt. January 12,1579 –December 30, 1644) was an , , and . He worked during the years justafter and, and is sometimesconsidered to be "the founder of ".Van Helmont is remembered today largely for his ideas onspontaneous generation, his 5-year tree experiment, and hisintroduction of the word "gas" (from the Greek word chaos)into the vocabulary of scientists.


by Jan Baptista van Helmont, ..

Discuss and write up possible ways you might test your group’s ideas.” After 10 minutes encourage students to share some of their ideas about where the tree’s mass came from after reviewing van Helmont’s experiment?

Van Helmont and John Woodward in Photosynthesis

At this time share with the students that scientists have indeed come up with an explanation of how plants get the food they need to grow from a small seed or as in van Helmont’s experiment from a sapling to a tree.

Video clip - Van Helmont's experiments on plant growth

Explain to the students that at the time he was performing his experiments, the composition of the air was unknown and van Helmont didn’t know about carbon dioxide in the air.