Jan Baptista van Helmont was born in
Belgium in
1580. He was the first scientist to differentiate between gases and air. He was also a pioneer in an early form of
biochemistry, then called
iatrochemistry, and the use of chemical medicines, a forerunner to modern
pharmacology.
Helmont thought that the most basic elements in the universe were water and air. He also believed that plants were made up solely of water. He proved this to himself by planting a willow of known weight in soil of known weight. He weighed them five years later and found that the tree had gained almost 170 pounds while the soil had lost almost no weight at all. He hypothesized that the tree had gained weight by absorbing water. We now know that this can be attributed to photosynthesis.
Helmont was also instrumental in research on the digestive system, suggesting that alkali metals could be used to treat digestive disturbances. His Ortus Medicinae; vel, Opera et Opuscula Omnia (The Fount of Medicine; or, Complete Works) was published posthumously in 1648, four years after his death.