Today in Science History
On January 12 in 1580, Jan Baptist van Helmont, the father of biochemistry and originator of the term "gas," is born into a noble family in Brussels. Although he was an alchemist and his explanations often involved mysticism, he made an everlasting contribution to science by being the first to conduct biological experiments in which the conditions and results were numerically measured. He performed one of the most famous experiments in biology by growing a willow tree in a precise quantity of soil, to which only water was added; after five years the tree had gained 164 pounds, but the soil had lost only 2 ounces. He erroneously concluded that the water was the major source of the tree's nourishment. Ironically, air's carbon dioxide (which Helmont also discovered) contributes most to the tree's growth.
[ from The Illustrated Almanac of Science, Technology, and Invention ]