Jan Baptist Van Helmont - Career As Chemistry Pioneer

Career As Chemistry Pioneer

Van Helmont is regarded as 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. For Van Helmont, air and water were the two primitive elements. Fire he explicitly denied to be an element, and earth is not one because it can be reduced to water.

Van Helmont was a man of contradictions. On the one hand, he was a disciple of Paracelsus (though he scornfully repudiated his errors as well as those of most other contemporary authorities), a mystic and alchemist. On the other hand, he was touched with the new learning based on experiment that was producing men like William Harvey, Galileo Galilei and Francis Bacon. Van Helmont was a careful observer of nature; it can be inferred that from his analysis of data gathered in his experiments suggested he had a concept of the conservation of mass. He performed an experiment to determine where plants get their mass. He grew a willow tree 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 lbs (74 kg). Since the amount of soil was basically the same as it had been when he started his experiment, he deduced that the tree's weight gain had come from water. Since it had received nothing but water and the soil weighed practically the same as at the beginning, he argued that the increased weight of wood, bark and roots had been formed from water alone. However, this "deduction" is incomplete, as a large proportion of the mass of the tree comes from atmospheric carbon dioxide, which, in conjunction with water, is turned into carbohydrates via photosynthesis.