Jan Baptist van Helmont

Jan Baptist van Helmont was a chemist, physiologist, and physician from Brussels who worked in the decades following Paracelsus and the rise of iatrochemistry. Born on 12 January 1580, he conducted his famous willow tree experiment over five years, meticulously tracking growth and weight in an early attempt at quantitative biology. He introduced the word "gas" into scientific vocabulary, deriving it from the Greek "chaos". Sometimes called the founder of pneumatic chemistry, he also developed ideas on spontaneous generation that would shape debates for centuries. He died in Brussels on 30 Dece…