Books of Secrets: Writing and Reading Alchemy

Chemical Heritage Foundation, Philadelphia, Pennsylvania. Until 4 September.

The sixteenth-century physician and alchemist Paracelsus claimed, “Not even a dog killer can learn his trade from books, but only from experience.” As later 'experimental philosophers' turned alchemy into chemistry, they retained this affectation: in the seventeenth century, Robert Boyle is said to have claimed that he had learnt “more from men, real experiments, and his laboratory ... than from books”.

Such comments seem to imply that alchemy and the transitional discipline of 'chymistry' were all about bench-top graft, in contrast to the medieval tradition of seeking knowledge in the library. Yet in most paintings of alchemists at work in the sixteenth and seventeenth centuries, books are ostentatiously on show. Apparatus lies unheeded or broken while the alchemist pores over a text, papers sometimes cascading in comic profusion from desk to floor. In these images, books matter very much indeed: they seem to be where the real secrets lie.

This vexed relationship is examined in Books of Secrets, an exhibition at the Chemical Heritage Foundation (CHF) in Philadelphia, Pennsylvania. Juxtaposing fifteenth-century alchemical books and manuscripts recently acquired by the CHF with its extensive collection of paintings of alchemists at their labours, the exhibition explores this early literature of proto-science, and what it was for.

Alchemical books varied significantly. Some were esoteric treatises, all cryptic diagrams and encoded instructions for conducting 'rubification' and other chemical procedures. Others were cheaply printed or hastily copied compilations of miscellaneous recipes for dyes, soaps and medicines. Both were apt to be marketed as 'books of secrets'. The term seems to promise forbidden, mystical insights, but could also simply mean tricks of the trade.

This alchemical manual may have become soot-smeared over a furnace. Credit: Les Enluminures

The new acquisitions, originally part of the Bibliotheca Philosophica Hermetica in Amsterdam, include both handwritten and printed documents, some attributed (often spuriously) to famous alchemists including Raymond Lull and Petrus Bonus. They reveal the character and functions of the literary culture of nascent chemical science from the Renaissance to the early Enlightenment.

The books were evidently well used. The pages of one fifteenth-century compilation of Italian and English manuscripts arrived covered in dirt — or perhaps soot, from being read over a smoky furnace. The CHF's curator of rare books, James Voelkel, persuaded conservator Rebecca Smyrl to avoid cleaning the pages: the 'dirt' may be a remnant of experiments. “It could be something someone was trying to turn into gold,” says Smyrl.

To peruse these books is to glimpse a lively dialogue between author and reader. Despite the volumes' costliness, some have words or passages crossed out or altered. In one sixteenth-century handwritten work, comments are squeezed into every corner of the margins: it is as much lab notebook as reference source.

On this evidence, the painters had it right, even if their depictions of alchemists often owed more to convention than observation. This band of proto-scientists engaged intimately with the words on the page. The text was not sacred, but it was indispensable.