Teaching alchemically

In medieval ‘how-to’ literature, one of the most frequently encountered methods for expounding knowledge is through dialogue. Whether literary, philosophical or technical, dialogues provided a modus docendi for all kinds of subject matter, from Latin grammar to the pursuit of love.Footnote ¹² The format virtually reconstructs pedagogical relationships, dramatizing lists of ‘frequently asked questions’ in which a master delivers suitable precepts and responds to his pupils’ concerns. The role of master could also be assumed by historical and allegorical figures: most famously by the personification of Philosophy in Boethius's Consolation of Philosophy, in whose presence the philosopher assumes the role of acolyte.Footnote ¹³

Such literary imaginings of the master–disciple relationship were particularly apt for alchemy, as a body of knowledge that was both philosophical and technical in content, but which lacked formal mechanisms of instruction. Dialogues re-created the conditions under which secret knowledge might be privately communicated, whether by an anonymous magister, a named authority or an allegorical personification such as Nature or Philosophy. Examples already proliferate in the early Greek alchemical corpus, from the dialogue of Synesius and Dioscorus (in which the philosopher Synesius expounds a still earlier authority, Pseudo-Democritus), to a set of dialogues involving the female alchemist Cleopatra, who takes on the role either of student or of master, depending on her audience.Footnote ¹⁴

In text after text, eager students press their ‘master’ for advice on solving alchemical problems. Yet these problems are typically less concerned with communicating technical skills than they are with construing texts. In one of the earliest such examples, a disciple of Synesius seeks advice on interpreting the writings of Pseudo-Democritus:

Here technical instruction is filtered through the exposition of ‘philosophical’ speech: a distinctive feature of alchemical literature that was duly adopted by Arabic and Latin commentators. To transform nature, the argument goes, it is first necessary to understand nature; an enquiry into causes that is the remit not of the artisan, but of the philosopher. The result is a body of instructional literature that claims to offer practical mastery, but only within the framework of learned discourse: an outlook that at times assumes an explicitly anti-artisanal flavour.Footnote ¹⁶

This tone is particularly noticeable in the context of fourteenth-century philosophical treatises written after alchemy had been effectively excluded from the medieval university curriculum. These include a range of influential but largely pseudonymous writings attributed to scholarly authorities like the Montpellier physician Arnald of Villanova (c.1240–1311), Majorcan philosopher Ramon Llull (1232–1316), and English monk John Dastin (c.1295–before 1386).Footnote ¹⁷ Since the ability to read texts on multiple levels, including allegorically, is the remit of the scholar, these authorities argue that an unlearned practitioner cannot prosper in the science of alchemy.

This point is made explicit in the De secretis naturae, a fourteenth-century treatise pseudonymously attributed to Arnald of Villanova. The text consists of a dialogue in which the master assures his disciple that ‘no one should therefore come to this art unless he has first learned logic, and afterwards philosophy, and knows the causes and natures of things’.Footnote ¹⁸ While this emphasis on causes helps to situate alchemy within Aristotelian natural philosophy, it also distinguishes the context of alchemical learning from artisanal apprenticeship. Reading alchemically means reading philosophically, which in turn means approaching texts on multiple levels, rather than accepting terms at face value, as in a recipe. Accordingly, the value of an alchemical treatise at least partly resides in the author's ability to expound the philosophers’ language.

In the preface to De secretis naturae, the master signals this method by announcing some of the terms that he intends to explicate:

As Pseudo-Arnald's alliterative warning makes clear, the aim of the text is not to provide literal, step-by-step instruction of the kind furnished by traditional craft literature. Rather, obscure speech is deliberately employed to protect the knowledge of alchemy from ‘fools’. As the master explains, if a man were known to have the secret he would be pursued for it, and in the hands of the unworthy it might bring ruin to the world. Practitioners who abused such knowledge would then be answerable for their actions before God. For all these reasons, the master prays that God will grant him the ability to reveal the secret to the wise, while concealing it from the ignorant.Footnote ²⁰

This pious rhetoric obscures a more pragmatic agenda. Pseudo-Arnald here uses the magisterial framing to promote his own approach to alchemy, namely a practical and theoretical commitment to using metallic rather than organic ingredients in the work of chrysopoiea (gold-making). Much of the pseudo-Arnaldian corpus belongs to a ‘mercurialist’ tradition that viewed metallic bodies, particularly quicksilver, as the most appropriate basis for operations intended to produce gold and silver.Footnote ²¹ Since this contradicted authorities who advocated the use of blood, eggs and other organic ingredients, one strategy was to forcibly reinterpret these writings by reading such substances as cover names, or Decknamen. Accordingly, the magister warns that, while the philosophers state that the stone is made from herbs, eggs or blood, such terms must be understood not literally but philosophically. Fools who read only ‘according to the letter’ have wasted their labour on eggs, blood, salts and so forth, ‘because they did not well understand the words of the philosophers, speaking obscurely’.Footnote ²² For instance, although the philosophers used ‘blood’ in a purely metaphorical sense to refer to the stone's red colour, the term is misunderstood by fools, who ‘have worked on blood and found nothing’.Footnote ²³

These instructions were later taken seriously as advice for the correct interpretation of alchemical books. Through such expository techniques, readers who had never studied natural philosophy in a formal educational setting could still learn to read alchemically from medieval texts. Books like De secretis naturae, which circulated both under Arnald's name and in an anonymous form as the Dialogus inter magistrum et discipulum, continued to serve as important sources of information on alchemical philosophy throughout the fifteenth and sixteenth centuries, while also providing exemplars for new treatises. In the process, they helped to enshrine mercurialist precepts – such as a disdain for salts and organic ingredients in favour of the metallic trinity of gold, silver and mercury – in alchemical lore.

In England, for instance, the second half of the fifteenth century witnessed a blossoming of didactic tracts on alchemy written both in Latin and in Middle English, which often follow the pseudo-Arnaldian model.Footnote ²⁴ The dialogue format, which offers advice on interpretive issues while reinforcing the authority and prestige of past philosophers, was retained in several versions. Thus one Middle English dialogue opens with a student's request for clarification of past errors in order to uphold the credibility of the science:

The novice goes on to press his teacher regarding various points of interpretation, and receives familiar answers, starting with the need to eschew animal and vegetable ingredients in favour of mineral ones. The master even cites Pseudo-Arnald's advice on Decknamen: ‘Therffore [th]e philosophers toke no heede to [th]e names but to [th]e properties of [th]e names. ffor, by one thynge they vnderstoode another’.Footnote ²⁶ Similar warnings are offered in another Middle English dialogue, also modelled on De secretis naturae, titled ‘certeyn necessary questions of a disciple and of the solucions therto made by his master touchyng the seid werke and materialles’.Footnote ²⁷ Here, through the catechetical form of a set of quaestiones, the disciple attempts to establish the true nature of the philosophers’ mercury, and learns the dangers of alchemical speech. The master offers a familiar warning: since ‘The philosophres in [t]her termes spekyn analogies’, their followers must ‘be ware of analogia for in the most derkist maner all this matter is hidde’.Footnote ²⁸ Mercury, for instance, may not always represent common quicksilver, but a powerful solvent drawn out of the bodies of metals.

By opening the gates to multiple levels of interpretation, these fictive masters offered exegetical opportunities to their readers. This is more than straightforward translation, whereby one Deckname is consistently interpreted in a given way. Rather, this mode of reading all but guarantees lexical slippage over time, as earlier texts are continually reread in light of new sources of evidence, including the results of experimentation. ‘Mercury’ could be interpreted in many different ways – and frequently was.Footnote ²⁹

The conventions of alchemical instruction literature also make it very easy for writers to disguise the fact that they have not yet (we presume) achieved the stone. But why write a ‘how-to’ treatise at all, if one has yet to personally discover the ‘how’? When we turn to the context of sixteenth-century England, it becomes clear that these writings played an important role beyond directing practical operations, although they undoubtedly served that end as well. Among communities of readers and practitioners, instructional treatises helped to support the prestige of alchemy as a branch of natural philosophy, and that of individual alchemists as true ‘philosophers’ – a persona viewed as particularly useful in the context of patronage.Footnote ³⁰ We can trace exactly this process in the case of one alchemist at the court of Henry VIII: Giles Du Wes. Not only does Du Wes's own philosophical dialogue survive, but also several of the manuscripts that he read as source material, as well as evidence for his correspondence with at least one other contemporary practitioner. The case therefore offers an unusual glimpse of a Henrician practitioner in the round, as a reader, a writer and – eventually – an authority in his own right.

Writing alchemically

Learning to read alchemically was not unlike learning a foreign language – one populated by ‘false friends’ that did not always produce the expected meaning. As the priest and tutor John Palsgrave (c.1485–1554) explained in the introduction to his 1530 French grammar, the phrasing of French differed from that used in English: ‘thoughe we shulde gyve worde for worde, yet the sens shulde moche differ betwene our tong and theyrs’.Footnote ³¹ Alchemical readers faced similar problems when interpreting difficult terms, but the language of alchemy could not be learned through casual conversation, nor gleaned from a single primer. In the absence of a definitive dictionary, readers turned to philosophical treatises for advice on translating the words of their authorities, including multivalent terms like ‘mercury’. In practice, these books were often just as obscure as the authorities they claimed to decipher – evidence, perhaps, that their writers had correctly learned the rhetorical lessons of past masters, and successfully put them to work in their own compositions.

In England, one important guide to alchemical reading was coincidentally written by the author of one of the earliest French textbooks, Giles Du Wes. Also known by his Latinized name of Ægidus de Vadis, Giles began his career in England as a musician at King Henry VII's court. After teaching French and lute playing to the king's children (including the future Henry VIII), he was put in charge of the royal library at Richmond Palace in 1506.Footnote ³² It was there that he composed his Dialogus inter naturam et filium philosophiae (Dialogue between Nature and a Son of Philosophy) in 1521, dedicating the work to an unnamed friend, most likely his fellow practitioner Sir Robert Greene of Welby (c.1467–after 1544).Footnote ³³

As the title suggests, this Latin treatise is presented as a dialogue between a would-be philosopher and the personification of Nature, who generously undertakes to tutor her disciple in the art of alchemy.Footnote ³⁴ Its form owes much to Du Wes's familiarity with medieval alchemical texts like the ‘Dialogue between a Master and a Disciple’, the anonymized version of the pseudo-Arnaldian De secretis naturae, which he owned (and personally repaired) in a fifteenth-century copy.Footnote ³⁵ As a teacher, however, Du Wes was also familiar with the use of dialogues in more conventional didactic settings. During the late 1520s he rounded out his pedagogical credentials with An introductorie for to lerne to rede, to pronounce and to speke French trewly, a grammar based on his experience of teaching Henry VIII's own daughter, Mary.Footnote ³⁶ The dialogic format is essential to the Introductorie, which includes a series of exercises framed as conversations between Giles and his royal pupil. In terms of content, these are designed to showcase a range of vocabulary while doubling as an etiquette manual for interacting with court dignitaries and their messengers. However, they also hint at Du Wes's philosophical interests. In one dialogue, Du Wes responds to Mary's questions on the nature of the soul with a natural-philosophical digression on the functions of human digestion: material that, as we shall see, he also used as an analogy for chemical operations in the alchemical Dialogus. Such interjections served to demonstrate Giles's learning and courtliness in ways that masked his humble minstrel origins. But the primary purpose of the exercise was not, of course, to teach readers philosophy – it was to allow them to practice their French, perhaps with the added frisson of learning page-by-page with the king's daughter.

Du Wes's French grammar thus offers some intriguing parallels with his Dialogus, which as a ‘manual’ of alchemy leaves much to be desired in terms of practical oversight of chemical operations. Rather, the text emphasizes the exegetical techniques necessary for readers to present themselves as educated specialists. The tone is set in the preface, which relates how the protagonist, after years of fruitless labour searching after the secrets of nature, has reached the point of abandoning alchemy altogether. He is hopelessly entangled in the enigmas and allegories of his source texts, ‘for all philosophers are sententious to such a degree, they are not content with a small level of difficulty but wrap up [the answer] in so many riddles that I don't think anyone could arrive at the desired outcome by themselves’.Footnote ³⁷ The alchemist's problems therefore arise not from a lack of technical skill (since he admits to having attempted a variety of practices already) so much as from his inability to understand his written sources, which are essential if he is to conclude the work successfully. As in the Introductorie, mastery of language is the ultimate goal of the book: a mastery that, once used to ‘translate’ the words of the authorities into clear speech, will raise even humble men to the rank of philosopher.

The difficulties of reading alchemically are stated particularly clearly in relation to the central problematic of the Dialogus: that of the philosophical proportion. The problem is introduced when the disciple asks Nature to reveal the correct proportion of ingredients used in making the stone. In a straightforward technical manual, we might expect straightforward answers. But the purpose of the dialogue is not to provide recipes or lists of quantities, and Nature does not interpret it as such. Rather, she takes the question as her cue to explain the methods by which the philosophers disguised their true meaning. One way is to discuss chemical operations by analogy. Nature demonstrates this skill herself, responding to the question of proportion by developing an analogy with human appetite:

At a superficial level, this looks like good advice. Different people (or even the same person under different conditions) will be satiated by different amounts of food: we discover the extent of our appetite only by satisfying it. Likewise, the alchemical adept must be able to adapt to the situation and ingredients at hand, rather than deciding in advance on a ‘one-size-fits-all’ procedure. This solution has important practical connotations, since the quality and quantity of the alchemist's matter will determine the amount of ‘feeding’ it requires: a problem often encountered in practicae such as George Ripley's Philorcium (a work which Du Wes partly transcribed), which warn against over-saturating one's ingredients with liquid.Footnote ³⁹

Yet Nature's advice to learn by doing is too simplistic for her disciple, since it ignores the underlying causes of chemical change. The amount that a given stomach can digest depends on its particular complexion: thus a hot and strong stomach will digest far more than one that is cold and weak. Since given ingredients have specific complexions, success must depend on combining them in the right proportion. The disciple concludes that Nature is treating him like a rustic rather than instructing him in the approved philosophical manner – that is, with reference to causes. He suspects that the work does rely on a ‘determinate measure’, and begs his preceptress to disclose it.Footnote ⁴⁰

Such bluntness gets short shrift from Nature. True philosophers do not communicate their knowledge so baldly – at least, not in writing:

For Du Wes, who had studied the writings of humanist scholars like Giovanni Pico della Mirandola (1463–1494) and Johannes Reuchlin (1455–1522), their Christianized version of Cabala offered an attractive analogy with alchemy.Footnote ⁴² Both were learned, esoteric traditions whose true sense was not conveyed in plain writing, but rather through oral communication and close textual exegesis. Like Cabalists, novice alchemists should therefore seek out a master willing to reveal the secret to them directly. Failing that, practical knowledge might still be set down in writing if appropriately disguised. While these texts made little sense on their own, a skilful reader could extract their meaning by comparing multiple authorities.

Thus, in a long passage often omitted in manuscript copies, Du Wes piles up aphorisms on the philosophical proportion culled from his own study of medieval sources. Although these often seem to contradict one another, Nature glibly assures her follower that their underlying coherence can be revealed by further study and reflection; or, failing that, with prayer:

The entire passage on proportion, from the stomach analogy to the long list of contradictory authorities, may seem unhelpful for those in need of step-by-step technical instruction. At no point does Nature actually explain what the correct proportion is. Having come this far, the disciple needs either to develop his own understanding to the point where he perceives the truth, or to find a master willing to convey the necessary information orally. Nature's advice does, however, offer important clues on how to approach alchemical texts, to both readers and prospective authors. Her series of examples demonstrates how analogies can be constructed to disguise alchemical problems, and shows how similar riddles can be solved when encountered elsewhere. Above all, Du Wes's compositional ambiguities mask the fact that he had yet to determine the correct proportion himself. As Nature responds to the disciple's questions, she voices the answers that Giles has arrived at through his own painstaking study and annotation of philosophical treatises, particularly pseudo-Lullian writings.

It is possible to partially reconstruct this process, because we actually have access to some of Giles's own manuscripts, which allow us to catch the librarian himself in the act of learning to read like a philosopher. In or around 1506, Giles annotated his copy of the Liber de secretis naturae, seu de quinta essentia (The Book of the Secrets of Nature, or, Concerning the Quintessence – not to be confused with the Arnaldian De secretis naturae), one of the core works of the pseudo-Lullian alchemical corpus.Footnote ⁴⁴ Here, the late fourteenth-century writer explains that the same alchemical ‘water’ can be congealed into either elixir or precious stones, ‘according as the matter is proportioned [to] either’.Footnote ⁴⁵ Giles underlined this passage, noting in the margin that these proportions were hard and difficult to determine, since none of the philosophers had fully explained them.Footnote ⁴⁶ Hints of his frustration linger in the Dialogus, written fifteen years later, where Nature and the disciple debate exactly this problem – although Nature's unresponsiveness suggests either that he failed to find a definitive answer, or that he preferred not to share his solution. For later readers, however, such vagueness over the problem of proportion could be readily interpreted as philosophical discretion rather than amateurish prevarication.

Du Wes knew that his books would be studied by others. Although the evidence for collaboration between English alchemists in the first half of the sixteenth century is generally much sparser than for later periods, Du Wes's manuscripts show that he did not study alchemy in isolation, but rather collected and composed texts with a view to instructing and impressing his peers. Indeed, he probably had a specific reader in mind: his fellow bibliophile (and likely social superior), Sir Robert Greene of Welby.Footnote ⁴⁷

Du Wes plied his colleague with both physical books and new, alchemical compositions. In 1532, he presented Greene with an alchemical manuscript, carefully copied and illustrated in his own hand. The book was composed of late medieval works as well as more recent writings, such as Augurello's Neo-Latin poem Chrysopoeia, all annotated by Du Wes.Footnote ⁴⁸ Greene acquired several more of Du Wes's books, including his annotated copy of the pseudo-Lullian Liber de secretis naturae, possibly after his friend's death in 1535. A note addressed to ‘Robert’ in another of Du Wes's manuscripts, and a reference to ‘Sir Robert’ accompanying an early translation of the Dialogus, suggest that Greene may even have been the anonymous dedicatee whom Du Wes praises in the preface to his work.Footnote ⁴⁹ Their relative social status is suggested by the fact that it is Du Wes, rather than Greene, who seems to have initiated correspondence in the form of gifts and dedications, while Greene later erased Du Wes's name from his former manuscripts – overlaying the librarian's signature with his own.Footnote ⁵⁰

Yet the content of Du Wes's writings suggests that, despite his lack of birth or conventional scholarly education, he nonetheless envisaged himself as Greene's equal in matters of alchemical philosophy. Such previously unnoticed associations between two prominent Henrician alchemists draw attention to a context of knowledge making in which alchemical manuscripts functioned not only as sources of practical instruction, but also as evidence for mastery in the techniques of alchemical exegesis – and hence as a form of both social and intellectual currency, suitable for scribal circulation among like-minded associates and even prospective patrons.

These advantages also benefited writers in the long term. Within a few decades Du Wes's reputation had eclipsed that of Greene, who abandoned alchemical practice in 1538 and bequeathed no substantial philosophical treatise to posterity.Footnote ⁵¹ In his own philosophical dialogue, Du Wes's readings of medieval manuscripts (some later owned by Greene) accreted authority as he translated them directly into Nature's pronouncements. These lessons were noted by later readers, who studied and transcribed the Dialogus long after Giles's death, both in its original Latin and in an English translation, the ‘Dialogue between Nature and a Disciple’.Footnote ⁵² For instance, when the Elizabethan alchemist Thomas Potter transcribed the English version in 1580, he drew attention to Nature's warnings, noting that the philosophers’ true proportion ‘may not be put in writinge’, for it is ‘[th]e kay of all our secretes’.Footnote ⁵³ In the margins of alchemical texts, conversations unfolded not between Nature and her baffled disciple, but between writers, their books and their future readers.

Reading for practice

As the sixteenth century progressed, the number of recorded suits from alchemical practitioners rose, partly in response to the known interest of influential royal administrators such as William Cecil, Lord Burghley (1520–98) and Sir Thomas Smith (1513–77) in both the chrysopoetic and medical applications of alchemy.Footnote ⁵⁴ Yet winning the support of powerful patrons like Cecil and his mistress, Elizabeth I, posed problems for practitioners who lacked courtly connections or a university education. For such petitioners, the philosophical framing offered by medieval authorities provided one model for achieving respectability. By the 1560s, large numbers of Latin treatises had been translated into English, providing fuel for a generation of English merchants and tradesmen who incorporated their lessons into their own practice – and also their own patronage suits.Footnote ⁵⁵

One such reader was the merchant Humfrey Lock, whose suit to Cecil has recently been edited by Peter Grund. As a gift for his patron, Lock composed a lengthy treatise consisting of excerpts from late medieval philosophical treatises, which include both Middle English compositions and ‘Englished’ versions of Latin works. In his dedication to Cecil, Lock lingers over the challenges presented by philosophical speech. For instance, he praises George Ripley's famous English poem the Compound of Alchemy (1471), for its usefulness in unpacking philosophical enigmas: ‘wherby I haue lerned to knowe the croked way and the matter that the philosofers hid and coverid vnder the mantill of philosofie’.Footnote ⁵⁶

For modern readers of Ripley's difficult, technical, partly allegorical poem, the compliment may seem tendentious at best. But Lock was well aware of the value that knotty philosophical texts represented to an ingenious reader, who might use them as a platform for his exegetical skills. A note in one copy of his Treatise reveals that Lock was hoping to be recalled from a troublesome posting in Moscow, trading on Cecil's well-known interest in alchemy to facilitate his return. Despite not yet having made the stone, Lock trusted that the very obscurity of his writing would intrigue his well-read patron:

Unfortunately Lock's own library does not survive in identifiable form to offer further insight into his reading practices. However, the arrangement of medieval material in the Treatise points to his access to a range of manuscripts which he studied closely for both practical and philosophical meaning. We are luckier in having access to annotated books owned by other alchemical suitors, ranging from university-educated humanists like Richard Eden (c.1520–76) and John Dee (1527–1609), to humbler figures, such as the clothworker Thomas Peter (fl. 1520s–1530s) and haberdasher Richard Walton (fl. 1560s).Footnote ⁵⁸

Walton is one of many English alchemists who lacked the scholarly credentials that authorities like Pseudo-Arnald demanded as the foundation for philosophical pursuits. The demands of his business also denied him time for study and contemplation, as he notes in his own treatise written for Elizabeth I, where he dwells wistfully on the opportunities available to ancient adepts who studied the liberal arts while financially supported by relatives and friends, ‘that they might giue their Mindes wholly to their studdy, and to the practize of those things by which by their learning they had the speculation of’.Footnote ⁵⁹ He nonetheless works hard to convince the queen that true knowledge of alchemy depends not just on book learning, but also on the providence of God, which opens the science to lowly as well as wealthy men.Footnote ⁶⁰ Accordingly, the ability to read texts alchemically is evidence not just of scholarship, but also of elect status.Footnote ⁶¹

Regardless of whether his exegetical prowess flowed from erudition or divine grace, Walton accepted mastery of Decknamen as an essential part of acquiring this philosophical craft. In his own annotations to Ripley's Compound, he observes that ‘every syence hathe hys proper tearmes’ – alchemy included. And he shows that he understands the lesson: one must learn the meaning of each and every one of these terms, ‘or ellse you shallt be no philosophors but a broyler’.Footnote ⁶² In fact, Walton's note is itself a quotation from another alchemical poem, Thomas Norton's Ordinal of Alchemy (1477), which he had transcribed in October 1565:

Perhaps even more so than Du Wes's scholarly dialogue, alchemical poems like the Compound and Ordinal confound modern notions of ‘how-to’ literature. Yet their writers’ reputations for successful practice, coupled with their sage advice on deciphering philosophical speech, ensured that their verses were routinely studied by readers concerned to extract practical information.Footnote ⁶⁴ For instance, Walton's notes to the Compound show that he was interested in Ripley's use of ‘gold’ and ‘silver’ as cover names for the true prime matter, a base metal: by ‘thys ys not \mente/ gollde & syllver vulger but phylosophicall’.Footnote ⁶⁵ Ripley's mystery ingredient contains gold and silver only in potentia, a point Walton underscores a few lines later: ‘the sprytte … of philosophers [is] neither golld nor syllver by natu[re] but by power’.Footnote ⁶⁶ Later, in his own suit to Elizabeth I, Walton alluded to this metal using another common Deckname, the Sol of Philosophers, to signal his understanding that common gold was not required.Footnote ⁶⁷ From his reading, Walton identified this crucial prime matter as a mercurial water. Armed with this secret, ‘Therefore, I learne to be begin’.

Walton's exegesis of Ripley's verbal substitutions opens a window into alchemists’ attempts to read for practice. Alchemical reading techniques enabled practitioners to extract workable, chemical procedures from highly obscure source material, while also furnishing them with the skills to re-encode the fruits of their own experience in new, ‘philosophical’ forms. Lock's Treatise dedicated to Cecil and Walton's letter to Elizabeth I testify to the careful application of such compositional skills, learned from Ripley and other long-dead masters and honed in contexts unimagined by those late medieval authorities – ranging from the English merchant community in imperial Russia to a haberdasher's shop in Protestant London.

Seeking patronage was not the only pragmatic context wherein such techniques might be employed. Substituting the names of ingredients in correspondence, for instance, might protect the value of potentially lucrative secrets, particularly when communicating over distance. We find a striking example of such a technique on the parchment flyleaves of one late fifteenth-century alchemical manuscript, now MS Sloane 3747. Here, an Elizabethan reader has used the waste space to jot down a series of queries and instructions addressed to an unknown correspondent – questions which suggest the ways in which alchemical reading might shape actual discussions between practitioners.

In his notes, the annotator of Sloane 3747 shows that he has digested the lessons of the philosophical texts contained in the manuscript itself. Alongside other notes and queries, he advises his friend on the precautions to take when penning his response, in order to disguise the content of his recipes. ‘In your lettres to me’, he instructs, ‘call golde Antymony’. Copper should be referred to as tutia; silver as arsenic; mercury as orpiment; lead as sal ammoniac; iron as flint; tin as talc; sulphur as ‘Scales of Iron’; and ‘Vitrioll of Copper’ as minium. However, the ‘mercury of mercury’ may still pass under that name, ‘for few knowe it’. Ingredients are not the only kind of information to be disguised: unfortunately for modern historians, the writer's correspondent is also advised to conceal his identity: ‘Your owne name woulde not be set downe’.Footnote ⁶⁸

For the annotator, these verbal substitutions apparently had real-world application, since he asks his colleague to use them in their subsequent correspondence. Either his associate was already abroad at the time of writing or else his departure from England was imminent, since the annotator begs him to ‘Enquier of Paull at hamburgh [whether a] booke dedicated to her Majestie was deliverde’. He also asks him to secure two copies of Thomas de Kempis's The Imitation of Christ while on the Continent, ‘One for you, an other for me’ – but preferably not the 1563 translation made by the French Protestant theologian Sebastian Castellio (1515–63), for ‘the other is truer’.Footnote ⁶⁹

This usage is particularly intriguing, because Sloane 3747 is one of the most important surviving repositories of fifteenth-century English alchemica, containing the earliest extant copies of numerous texts in verse and prose.Footnote ⁷⁰ These include several Middle English didactic writings, of which two are in dialogic form: the prose tract Certeyn necessary questions (discussed briefly above), and a poem sometimes attributed to Ripley, the Mistery of alchemists.Footnote ⁷¹ The reader's notes suggest that he has absorbed the lessons of such sources – but also that he finds their contents insufficient on their own.

For this reason, the annotator's friend is expected to return from abroad with more than books alone. The mysterious Paul of Hamburg is apparently also an alchemist, whose knowledge the annotator hopes to tap regarding some of the technical aspects of chemical operations. For instance, when regulating the fire, what signs indicate when there is ‘to muche heat or to litle’ at the start of the work? As the writer well knew, such physical indications – the fruit of experience rather than scholarship – are all but impossible to convey in written form. He therefore asks his friend to pay attention to all aspects of Paul's practice during his visit: ‘Be curious in preparations, Signes, Tyme, fiers or heates, vessells’.Footnote ⁷²

He also seeks knowledge from Paul that post-dates the kind of practical insight available from medieval sources. The majority of his queries are, in fact, less concerned with Paul's physical practice than with the interpretive problems of construing a new body of knowledge: the iatrochemical writings of the iconoclastic Swiss medical reformer Theophrastus von Hohenheim, or Paracelsus (1493–1541).Footnote ⁷³ The annotator of Sloane 3747 has evidently read Paracelsus's Archidoxis, yet struggles to understand the meaning of his obscure terminology, perhaps understandably given Paracelsus's penchant for neologisms, and his unconventional use of quintessences and other chemical products of the kind described in medieval authorities, including Sloane 3747 itself.Footnote ⁷⁴ He thus charges his correspondent to learn from Paul, ‘What his opynion of the Compounde Electrum of Paracelsus may be’, and ‘What Prima materia [it is] which Paracelsus noteth in his foure Arcana in his Archidoxis’.Footnote ⁷⁵ The slippery identity of mercury requires particular clarification. What substance does Paracelsus intend by ‘mercury vitae’? And should antimony ‘be subli[med] with [mercury] of th'elementes aforesaid, or with [mercury of] mercury, which you knowe’?

This list gives us one half of a real-life dialogue between two Elizabethan readers, offering tantalizing glimpses of an otherwise unwitnessed conversation between the writer's correspondent and the mysterious Paul of Hamburg. In this conversation, practical concerns are shaped by the experience of reading – the writer's final choice of ingredients depending on both exegesis of a text and the experience of a practising alchemist in a German workshop. Such cases reveal an economy of alchemical knowledge based on multiple sources of information, from bookish study to personal experimentation: activities that typically took place not in isolation, but within networks of readers, patrons and practitioners. Authoritative treatises played an important role within that economy, not just as introductions to the theory and practice of alchemy, but also as guides to, and expressions of, correct philosophical conduct. In the dialogue between text and practice, neither could be wholly teased apart from the other.