French physicist René Antoine Ferchault Reaumur (1683-1757) believed carbon might be an element.
Coal, soot, and diamonds are all nearly pure forms of carbon.
Their densities vary depending on where they originate. The combustion (burning) of coal gave rise to the Industrial Revolution (1700-1900).
Another highly important and very unusual property of carbon is its ability to form long chains.
Carbon also occurs in a form, discovered only recently, known as fullerenes or buckyballs.
Buckyball carbon holds the promise for opening a whole new field of chemistry (see accompanying sidebar).