Jan Baptist van Helmont

Jan Baptista van Helmont, date unknown.

Jan Baptist van Helmont (12 January 1580 – 30 December 1644) was a chemist, physiologist, and physician from Brussels. He worked during the years just after Paracelsus and the rise of iatrochemistry, and is sometimes considered to be "the founder of pneumatic chemistry". Van Helmont is remembered today largely for his 5-year willow tree experiment, his introduction of the word "gas" (from the Greek word chaos) into the vocabulary of science, and his ideas on spontaneous generation.