The writing of the alchemists: signs for metals, planets and elements

Opening a seventeenth-century treatise on alchemy means facing a page dotted with circles, crescents, crosses and triangles. They are not decorations: they are words. For centuries alchemists wrote the names of metals, substances and operations with signs of their own, which formed a kind of alphabet at once technical and symbolic. Understanding these signs is the first step towards reading a literature that deliberately hid behind images and riddles.

The Greek origins

The oldest alchemical symbols are found in the Byzantine Greek manuscripts that preserve the texts of the Alexandrian alchemists, such as Zosimus of Panopolis, who lived around AD 300. One of the most important is a codex in the Biblioteca Marciana in Venice, datable between the tenth and eleventh centuries, which also contains lists of signs with their explanation. In these tables the sun indicates gold, the moon silver, and other signs designate substances and processes.

The practice of associating metals with planets is ancient and already found in late antique culture. Seven planets were known, counting the Sun and the Moon, and there were seven principal metals. Each pair shared a common sign: the circle with a dot for the Sun and gold, the crescent for the Moon and silver, the signs of Mars for iron, of Venus for copper, of Mercury for quicksilver, of Jupiter for tin and of Saturn for lead.

An ever-growing lexicon

In the Latin Middle Ages and the Renaissance the repertory expanded enormously. Beside the metals appeared signs for sulphur, salt, antimony, vitriol, arsenic and dozens of other substances. Symbols were added for operations, such as distillation, calcination or sublimation, and for laboratory instruments. Often the same substance had several signs, and the same sign could change meaning from one author to another.

The four elements were represented by triangles: point upwards for fire, downwards for water, and with a horizontal line for air and earth. This convention, which became classic, is attested above all from the early modern period. In the seventeenth and eighteenth centuries tables and dictionaries were printed gathering hundreds of signs, useful to apothecaries and chemists who had to decipher older recipes and manuscripts.

Secrecy and transmission

Writing in symbols also served the purpose of confidentiality. Alchemists were convinced that their knowledge should not fall into unworthy hands, and preferred to express themselves through allegories, mythological names and signs understandable only to initiates. The symbol made it possible to abbreviate, but also to veil: those who did not know the key saw only mysterious figures.

At the end of the eighteenth century modern chemistry abandoned this tradition. In 1787 Antoine-Laurent Lavoisier and his collaborators published the Méthode de nomenclature chimique, which introduced systematic names for substances. At the beginning of the nineteenth century John Dalton proposed circular symbols for atoms, and shortly afterwards Jöns Jacob Berzelius adopted the initial letters of the Latin names of the elements, such as Au for gold and Ag for silver, the system still in use today.

Yet the signs of the alchemists have not disappeared. They survive in the planetary symbols used by astronomers and astrologers, in those for male and female, which derive from the signs of Mars and Venus, and in the imagery of books, films and works of art. They are the visible legacy of a long attempt to write matter in the language of the sky.