Antimony

Antimony reached the ancient world as stibnite, a soft grey sulfide mineral with a metallic sheen that grinds easily to a black powder. That powder is kohl, used as eye paint in Egypt and across the Near East from at least the third millennium BCE, and it gives the element its symbol: Latin stibium, from Greek stimmi, from an Egyptian word.

The eye paint was cosmetic and also practical, reducing glare and, according to a body of modern work on Egyptian samples, offering some protection against eye infection. Not all ancient kohl was antimony; a great deal of it was galena, a lead sulfide, and the two were not distinguished.

The alchemical symbol usually given for antimony is a circle surmounted by a cross, the same figure used for the orb of the world and the reverse of the sign for Venus. Its regulus, the star-patterned crystalline metal obtained by reducing stibnite with iron, was regarded as significant precisely because the star appeared: a visible sign in the metal itself, which invited reading. Isaac Newton, whose alchemical papers run to roughly a million words, worked extensively on the star regulus of antimony.

Antimony expands slightly on freezing, which is rare among metals and useful. Type metal, the lead-tin-antimony alloy used for movable type from Gutenberg onward, fills the mould completely as it solidifies and takes a sharp face. Every book printed from cast type before the twentieth century depended on that property.

The seven-metal scheme required exactly seven metals, because there were exactly seven classical planets. It was tidy, it was old, and it stopped being true.

Antimony, bismuth and zinc are the substances that broke it. All three are unmistakably metals. All three were being isolated, described and used in Europe by the sixteenth century. None of them had a planet, because the ancients had not known them and the sky had no more planets to offer. The scheme of correspondences was not refuted by argument; it was simply outgrown, and the way sixteenth and seventeenth-century writers handle the surplus metals, sometimes by assigning them to planets already taken, sometimes by ignoring the question entirely, is one of the clearest visible signs of a system under strain. Platinum in the eighteenth century and the flood of new elements in the nineteenth finished the job.

Antimony's own literature is dominated by one book. The Triumphal Chariot of Antimony appeared in German in 1604, edited by Johann Thoelde, and is attributed to Basil Valentine, described as a fifteenth-century Benedictine monk of Erfurt. It is a detailed and practical work on the preparation and medical use of antimony compounds, and it was enormously influential.

Basil Valentine almost certainly did not exist. No monk of that name is recorded at Erfurt, the works attributed to him refer to substances and techniques unknown in the fifteenth century, and the modern consensus is that Thoelde himself, or someone in his circle, wrote them and backdated the authorship for authority. This matters because the attribution is still repeated as fact in a great deal of popular writing. The text is real, important and worth reading; the fifteenth-century monk is not.

Antimony compounds were used medically as emetics, and the perpetual pill, a small ball of metallic antimony swallowed to induce vomiting and recovered afterwards for reuse, is genuine. Antimonial remedies were controversial enough that the Paris medical faculty banned them in 1566 and reinstated them in 1666, a hundred-year quarrel known as the antimony war.