Jan Baptista van Helmont was a Flemish physician who was born around 1579. He discovered that trees gained mass from water, not the soil. In one of his experiments, he planted a 2.2 kilogram willow in 90 kilograms of soil and kept it indoors for five years, adding water as needed. After five years, he weighed the tree again, and found that the tree had grown to 77 kilograms, but the soil had lost only 57 grams of weight. Van Helmont coined the term "gas" to refer to unidentified components of air. It is derived from the Greek word for gas - *khaos*. Gas became a standard term after the 18th-century French chemist Antoine-Laurent Lavoisier began using it. In one of his experiments, Van Helmont burned 28 kilograms of charcoal and found only half a kilogram of ash remaining. He concluded that the remaining mass must have escaped into the air as "gas". British chemist James R. Partington said of van Helmont: “He represents the transition from alchemy to chemistry, and is a worthy predecessor of Boyle.” --- Source: [[Soil]]