Jan Baptist van Helmont (1580-1644), Flemish chemist, physiologist, and physician. He married well and retired early from his medical practice and occupied himself with chemical experiments. He is sometimes considered to be the founder of pneumatic chemistry as he was the first to understand that there are gases distinct in kind from atmospheric air. The very word gas he claimed as his own invention, and he perceived that his gas sylvestre (carbon dioxide) given off by burning charcoal, was the same as that produced by fermenting must, which sometimes renders the air of caves unbreathable. To determine where plants get their mass he grew a willow tree in a pot and measured the amount of soil, the weight of the tree and the water he added. After five years the plant had gained about 164 pounds. He argued that water was the source of the extra mass and the plant's source of life. | |
Lizenzart: | Lizenzpflichtig |
Credit: | Science Photo Library / Science Source / NLM |
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