In the forms of charcoal and soot, carbon has been known for thousands of years. It was used in inks by the ancient Egyptians, and in so-called lead pencils manufactured by the English in the second half of the sixteenth century. By the eighteenth century it had been recognized as an element, and was named by Antoine Laurent Lavoisier in 1789, from the Latin, {Icarbo}, meaning 'charcoal'. In 1807, J÷ns Jacob Berzelius classified those carbon compounds found in living organisms as 'organic' compounds, a term still used today to describe carbon chemistry.
Silicon too has a long history. Present in most rocks and stones, the element was used in the primitive implements and weapons fashioned by stone age peoples. Such uses date back as far as half a million years ago. The element itself was first isolated in 1824 by the Swedish chemist, J÷ns Jacob Berzelius. In the second half of the twentieth century, the semiconductor properties of silicon have been crucial in the development of electronics technology.
In 1871, Dmitri Mendeleyev predicted the properties of germanium, or 'eka-silicon', as he termed the then-undiscovered element, with great accuracy. It was discovered fifteen years later by the German scientist, Clemens Alexander Winkler.
Tin and lead, on the other hand, have been known for thousands of years. Lead was used by the Romans in the construction of water pipes, and tin was widely used during the Bronze Age in weapons and implements. Both elements were used in solder at least two thousand years ago.
