Silicon was used in stone age implements half a million years ago; carbon, in the form of charcoal and soot, was known to the ancients; borax, a compound of boron, was used in glazing and glassmaking; sulphur is described in the Bible as fuelling the fires of hell; and arsenic has a long history as both a medicine and a poison.
But it is only in the last two or three hundred years that the idea of an 'element' has become clearly understood, and that scientific methods have reached the level of sophistication necessary for isolating elements from their compounds and mixtures. So oxygen, despite its omnipresence, was first identified as an element only in 1772, by Carl Wilhelm Scheele, and phoshorus, despite being a constituent of bones, was first isolated only in 1669, by the German alchemist, Hennig Brandt.
Not all non-metals have lengthy histories, however. Astatine, for example, was created artificially in 1940 by a team of American scientists which included Emilio SegrΘ.
