Category Archives: Alchemy

Alchemy, Experimentation, Ingredients, Posts, Series: Minerals, Tools and Techniques

Archaeology and early modern glassmaking recipes: The case of Oxford’s Old Ashmolean laboratory.

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By Umberto Veronesi

Crystal blown bottle decorated with milk glass festoon (festoni di lattimo), c. 17th c., Venice. Image courtesy of Wikimedia Commons.
Crystal blown bottle decorated with milk glass festoon (festoni di lattimo), c. 17th c., Venice. Image courtesy of Wikimedia Commons.

The product of human ingenuity, glass perfectly embodies the alchemical power to imitate nature by art and since the Bronze Age it has proved an incredibly hard substance to classify. Although glass only requires sand, salts and the action of fire, a quick look at any recipe collection will reveal that glassmakers have used a vast array of ingredients depending on what materials were available to them and on the physico-chemical characteristics desired. Colours and opacity were provided by the addition of the right metallic oxides, but even a perfectly colourless glass required specific reagents.[i]

Here, I am going to explore three 17th-century recipes for white enamels, what Venetians called lattimo. Enamels are glass pastes that could be coloured according to the need and then used as paint or to counterfeit gems. There are plenty of recipes out there, many are listed in Antonio Neri’ L’Arte Vetraria. However, in this post I am going to take my start from a different set of “primary” sources, namely the very crucibles used to manufacture white enamel at one of Europe’s leading chymical laboratories, the Old Ashmolean in Oxford. The residues found stuck to the walls of the vessels (Fig. 1) contain the chemical fingerprint of the ingredients used. The analysis of small cross-sections of such residues with a scanning electron microscope (SEM) are therefore a way to explore the recipes.

Figure 2. Crucible fragments analysed with glassmaking residues.
Figure 2. Crucible fragments analysed with glassmaking residues.

The chemical composition of the three residues shows both similarities and important differences. All of them have high levels of silica, corresponding to sand, the main component of glass. To melt silica a fondant is essential, and it needs to be added to the crucible. Here, two residues (B and C) bear the traces of a potassium-based fondant, probably saltpetre or even salt of tartar. Residue A has sodium oxide instead, which means that a different fondant was, pure soda most likely. Recipe-wise, this is the first relevant difference. Next, a reagent must also be added in order to render the glass paste white and opaque. A look at the microstructure of the residues (Fig. 2-4) helps identify what such reagents were and what different choices were made[ii].A (Fig. 2). The white aggregates visible in cross-section are the remnant of a mixture made of lead and tin calcined and then added to the crucible. This, together with somewhat large grains of sand, would produce the required colour and opacity.

Figure 3. SEM image of residue A showing dark sand grains and remains of lead-tin calx used as opacifying agent.
Figure 3. SEM image of residue A showing dark sand grains and remains of lead-tin calx used as opacifying agent.

B (Fig. 3). Here too crystals can be seen scattered throughout the glass and, like before, these are responsible for an opaque white enamel. However, these are made of tin oxide only, indicating that in this case the calx did not contain lead.

Figure 4. SEM image of residue B showing the tin oxide crystals as opacifying agent.
Figure 4. SEM image of residue B showing the tin oxide crystals as opacifying agent.

C (Fig. 4). There seems to be a third lattimo recipe being tested at the Old Ashmolean. This is more than a simple variant because it used a wholly different type of reagent, the antimony ore stibnite. The glass is indeed rich in antimony oxide while the microstructure reveals small white opacifying particles. These are a compound made of calcium and antimony that form when stibnite is added to the glass and heated. Such recipe is less common in technical writings, but it is reported in Christopher Merret’s commentary to Antonio Neri’s glassmaking treatise.[iii]

Figure 5. SEM image of residue C, showing the small opacifying crystals of calcium antimonate.
Figure 5. SEM image of residue C, showing the small opacifying crystals of calcium antimonate.

From this necessarily brief survey we can see that there is more than one way to make an opaque white glass paste. What is interesting is that such diversity happened at one of the leading chymical laboratories of its time, giving us an idea of the experimental nature of this enterprise. Making glasses was certainly a way of investigating nature, of looking at how transformations come about. At the same time, it was a way to test recipes for the industry. In this sense, artifacts can become a powerful tool for the history of recipes, another way to enter the arena of artisanal knowledge.

[i] Cable Michael 2001, p. 307.

[ii] Neri’s recipes for white enamel can be found in: Cable Michael. The world’s most famous book on glassmaking. The Art of glass by Antonio Neri, translated into English by Christopher Merrett (The Society of Glass Technology, 2001), Book 3.

[iii] For a general survey on glassmaking I suggest chapters from: Janssens Koen (Ed.). Modern Methods for Analysing Archaeological and Historical Glass, 2013.

Umberto Veronesi  is a Ph.D. candidate at the Institute of Archaeology, University College London. His dissertation entitled, “The archaeology of laboratory experiments and early chemistry: Oxford to Jamestown and back” focuses on exploring the practice of alchemy through the lenses of the archaeological materials coming from early chemical laboratories and uses scientific archaeology as a means to inform historical research and questions. Veronesi received his BA in Archaeology from the Sapeinza Universita di Roma in 2013, and his MSc Technology and Analysis of Archaeological Materials from the Institute of Archaeology, University College London in 2014.

Alchemy, Antiquity, Experimentation, Material History, Posts, Pre Modern, Series: Metals, Tools and Techniques

Alchemical Recipes in the AlchemEast Project

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By Matteo Martelli

What makes a recipe alchemical? Its inclusion in an alchemical treatise, one might suggest. Indeed, naïve as it may sound, such a simple answer opens an interesting perspective from which to look at the ancient alchemical tradition.

The earliest alchemical writings produced in Graeco-Roman Egypt (1st-2nd c. AD) include recipes that describe a variety of techniques for dyeing and manipulating the natural world – a spectrum of practices that goes far beyond simple attempts to produce gold out of ‘vile’ metals. Some of these techniques, ancient authors claim, were inherited from the Egyptian or Babylonian tradition; others reached Byzantium or Baghdad, often through translations of Greek texts into Syriac and Arabic.

This long-lasting tradition is as fluid as the boundaries of ancient alchemy. By mapping the specific practices and recipes detailed in each alchemical work, it will be possible to investigate changing ideas of alchemy over time as well as how these ideas responded to specific technological settings. On top of that, it will also be possible to follow the trajectories of single recipes which moved across works written in different languages or pertaining to different disciplines, such as medicine or natural philosophy.

Cinnabar (from the Monte Amiata mine, Tuscany) and metallic mercury

But let’s take an example from a set of texts that are being investigated in the framework of the ERC project AlchemEast, acronym for “Alchemy in the Making From ancient Babylonia via Graeco-Roman Egypt into the Byzantine, Syriac and Arabic traditions (1500 BCE – 1000 AD)”. Ancient natural philosophers and physicians recorded specific techniques for extracting mercury from cinnabar, its natural ore.

In his book On stones, Theophrastus, successor of Aristotle as head of the Lyceum, explained that it is possible to produce mercury by grinding cinnabar with vinegar in a copper mortar with a copper pestle.[1] The same procedure is described by Pliny the Elder, in book 32 of his Natural History, where the medical uses of minerals – mercury included! – are illustrated (NH 32.123).

Modern chemists noticed that these accounts actually described a mechano-chemical reaction between copper and cinnabar, a mercury sulfide: copper would react with sulfur, thus liberating free metallic mercury (chemically speaking, a redox reaction).[2] With the assistance of Lucia Maini and Massimo Gandolfi, two chemists of the AlchemEast team, we did replicate the technique with some adjustments. Rather than using a copper mortar – which proved to be very difficult to find in the shops that supply chemical labs today! – we decided to use a ceramic mortar where to grind pure cinnabar, acetic acid and copper powder.

Pure cinnabar, acetic acid and copper powder in a ceramic mortar

After grinding the mixture for a while, we were actually able to produce a layer of blackish powder (a mixture of metacinnabar and copper sulfide) on which a few drops of ‘dirty’ mercury were moving.

Mercury “floating” on a blackish layer of residues

The same procedure is described in ancient alchemical texts as well. The Graeco-Egyptian alchemist Zosimus of Panopolis (3rd-4th century AD) credits legendary figures, such as Maria the Jewess or Chymes, the eponymous hero of alchemy (called chymeia in Antiquity), with the use of similar technique for grinding cinnabar with vinegar in a lead or tin mortar.[3] Different metals were therefore used. In the lab, we actually tried to use tin rather than copper powder, thus obtaining a shiny mercury-tin amalgam.

Mercury-tin amalgam

We may preliminarily observe how this extraction technique was a kind of transdisciplinary know-how, shared by experts in different fields. A certain degree of variation is detectable in alchemical texts, which mention various metals. Moreover, ancient alchemists believed that mercury could be extracted from any metallic (or even mineral) body:  did this idea in some way depend on the empirical evidence they tried to conceptualize when treating cinnabar with a variety of metals?

This kind of questions are at the basis of the AlchemEast project, which explores ancient recipes from a double angle: as textual units that travelled over time and space; as invaluable windows on a wide spectrum of real practices and techniques. Textual criticism, replications, and historical investigations are critical keys to unlock ancient alchemical sources, from Babylonian tablets to Greek, Syriac and Arabic manuscripts.  This post is only a first, tentative attempt to illustrate how we applied this method, a preliminary result of our investigation, which, needless to say, is still “in the making.” We plan to continue keeping you posted in the following months.

[1] David E. Eichholz, Theophrastus, De Lapidibus, edited with Introduction, Translation and Commentary (Oxford: Clarendon Press, 1965), 81.
[2] Lazlo Takacs, “Quicksilver from Cinnabar. The First Documented Mechanochemical Reaction?” JOM. Journal of the Minerals, Metals and Materials Society, 52 (2000): 12-13.
[3] Marcelin Berthelot and Charles-Émile Ruelle, Collection des anciens alchimistes grecs (Paris: G. Steinheil, 1887-1888), vol. 2, 172. Part of Zosimus’ writings is only preserved in Syriac translation, where one finds further interesting details: cinnabar must be ground in the sun; copper filings are added to cinnabar and vinegar before grinding. The Syriac books of Zosimus will be published within the AlchemEast project.


Alchemy, Early Modern, Knowledge Transmission, Medicine, Posts

Receiving Alchemical Knowledge

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By Margaret Maurer

On two of the last leaves of receipt book compiled by Margarett Baker in the late-seventeenth century, there is a brief treatise that defines the practice of alchemy (fols. 133v-134r). Written in the same clear, italic script that on previous pages instructs how “To take out stayns or ink out of a linen Cloth” (38v) or recounts Mistress Malltes’ recipe “To make a… Cake” (42r), it begins:

Alchimy or spargyrike are accointed amongst the fore pillers of meddecen and w[hi]ch openeth and demonstrateth the compositions & desolutions of all boddies together w[i]th ther preparations terations & exaltations [th]e same I saie is shee w[hi]ch is the inuenter & scoole mistres of distllations…


Margaret Baker, V.a.619, Folger Shakespeare Library.

The passage continues by discussing different examples of alchemical transformation and outlining various alchemical processes. Using Early English Books Online, I found the original source of the passage was Thomas Tymme’s 1605 translation of Joseph du Chesne’s The practise of chymicall, and hermeticall physicke, for the preseruation of health. While it is possible that there are untraceable intermediary links that connect Du Chesne’s work with Baker’s, her manuscript also mimics the printed text’s form, separating out each alchemical procedure with its corresponding definition. The visual replication of the printed text signals a close connection between Tymme’s translation and Baker’s transcription.

Baker’s receipt book, fol. 133v. Credit: Folger Shakespeare Library.
Tymme’s translation of Du Chesne, p. AA4r. Credit: Folger Shakespeare Library.

Cross-referencing Baker’s receipt book with EEBO reveals that many of the recipes and passages contained within the volume replicate over a dozen printed sources, including numerous medicinal and alchemical texts. Much of the content is copied verbatim, although some passages have been restructured or given new titles. The most significant change is Baker’s non-standard spelling, which creates deviations that complicate database searches. Undoubtedly, the source texts found using EEBO are a small fraction of the total sources, printed and otherwise, that Baker appropriated when compiling her receipt book. However, identifying these passages illustrates the wide circulation and permeable boundaries of medicinal, alchemical, and domestic texts in early modern England.

Baker’s receipt book utilizes a wide array of medical and alchemical texts to construct a distinctively Paracelsian approach to domestic medicine. Apart from these hints about her intellectual world, we know relatively little about Margaret Baker’s life. Her name is preserved in three extant recipe books, but there are no further records about her life. The University of Essex’s “Baker Project” provides a detailed examination of the receipt book, including information and inferences about its author, construction, and provenance.

Baker’s receipt book draws from a diverse range of sources: surgery manuals and books of secrets, treatises on Paracelsian medicine and herbals. Alongside English physicians and surgeons, Baker copied English translations of continental writers from Switzerland, Italy, France, and the Netherlands. Additionally, the passages within Baker’s book span over 100 years − from John Day’s translation of Konrad Gesner’s The treasure of Euonymus (1559) to John Church’s A compendious enchiridion(1682). As Karen Bowman thoughtfully observes, Baker’s collection of receipts contains ingredients that illustrate a global market, but the texts contained within her book also point towards an international trade of ideas.

Simultaneously, the collection of sources that Baker gathered signals a specific and curated Paracelsian viewpoint. Many of the texts she has collected, including the passage copied from Du Chesne, reference Paracelsus, a Swiss doctor who rejected Hippocratic-Galenic medicine in favor of a chemical understanding of the human body. Paracelsus originally wrote that alchemy − along with philosophy, astrology, and ethics − was one of the four pillars of medicine. Du Chesne, a French physician and alchemist, transmitted this idea into Baker’s receipt book. Both Paracelsus and Du Chesne were associated with female alchemical and medical practitioners, who acted as the syncretic counterparts to university-trained doctors.

There is one difference between Baker’s transcription and Tymme’s translation of Du Chesne. While Tymme writes that, “ALchymie or Spagyrick, which some account among the foure pillers of medicine,” Baker’s version reads, “Alchimy or spargyrike are accointed amongst the fore pillers of meddecen,” removing “which some account” making alchemy’s foundational place a certainty. Since Paracelsian medicine became increasingly popular in England over the course of the seventeenth century, this change could reflect a larger cultural shift between Tymme’s translation and Baker’s transcription.

By definition, receipt books collect received knowledge, inherently entangled within dynamic social networks. Baker’s book is an assembly of ideas that she “received” from an impressive number of sources, both printed and unknowable. Even though Baker is not the original author of passages identified, she has a hand in constructing their shared meaning: a distinctly Paracelsian and thereby chemical approach to medicine. Acknowledging the sheer number of choices necessary for the book’s construction sheds a light on her role. For every passage she chose to copy over, she omitted hundreds, if not thousands, of additional recipes and treatises from her printed source material. Her role as the compiler was not only to receive knowledge, but also to choose what knowledge should be preserved on the page − what knowledge we, as readers, in turn, receive.


Alchemy, Beauty, Bodies, Medicine, Posts

Nature’s Coin: Beauty and Alchemy in Margaret Baker’s Book

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This two-part post is by a former student of mine, who also happens to be an author of popular history. Karen has written on fun things like fashion and Essex Girls (in history). Her original, longer post is taken from a digital group project on Margaret Baker’s recipe book that was complete for my 2016-7 module, The Digital Recipe Book Project.

By Karen Bowman

A delicate powder for the face, Margaret Baker, Folger Shakespeare Library, V.a.169, f. 97.

In the late seventeenth-century, recipe book compiler Margaret Baker listed twenty-eight recipes for beauty, amidst medicines for dropsy and distemper and recipes for custards and the stewing of racks of mutton. Baker’s recipes for beauty ranged from face powder and whitened hands to face waters and hair growth treatments (ff. 51, 109).  Baker had the chemical knowledge to beautify. Not only do the beauty treatments suggest her agency, status, and knowledge, but hint at strong connections between beauty and alchemy.

It was The Lady Croon’s recipe for pomatum (f. 106) that first caught my attention, pointing to chemical transformation in the social sense. While Lady Croon appears to be the author of the pomatum recipe, the contributor’s name “Mistress Anne Corbett” appears in the margin. If Mistress Corbett had passed on the recipe directly from Lady Croon, it seems likely that both had the means to make the pomatum and shared in an aristocratic social network (or aspired to one). Lady Croon’s pomatum was more than a means of creating a beautifying substance; the transference of knowledge was a gift that affirmed friendship bonds, social standing, and aspirations.

Pomatum was a greasy, waxy, or water-based substance used to style hair before applying powder. Given that powdered hair was a sign of class identity, the recipe suggests that Baker may had occasions to attend polite gatherings. Dressing one’s hair and caring for one’s skin required ‘self knowledge and inward identity and knowledge beyond one’s self reflecting an understanding of the body, its cultural and social meanings’ (Snook, 7). In a patriarchal society, in the absence of of wider legal and political representation, the ability to transform oneself was powerful information.

One’s face and body was the blank canvas for identity and social standing. For famed beauty Margaret Cavendish, Duchess of Newcastle (b. 1623), fair white skin was even political. She insisted that her mother was ‘a woman with perfect skin and politics’; skin thus represented social order and familial harmony–and, in her case, the Royalist cause. Other women, too, recognized beauty as nature’s coin and a way of forging identity within their own domestic structures and hierarchies.

Unknown, Lady at her Toilet, c. 1650-60. Source: Wikimedia Commons.

Of course, the real achievement for women was not the face and body they showed the world. It was the the female knowledge of how to manipulate nature through chemistry and alchemy in order to transform basic materials into healing and beautifying physic.

There were relatively few make-up items in Baker’s book, as we today would understand them. Many were even gender neutral. Her products include items to ‘take away heat and pimples in the face’, ‘to make a clense from spotts’, ‘waters for the face’, ‘to take away freckles’, ‘to stop hair falling and grow thicke’, ‘to take away chapped hands’, and to keep the face smooth’ (ff.14, 44, 51, 83, 109, 49, 92). In addition there are instructions for making ‘a butter to curl the hair’, ‘to make hands soft and white’, ‘make a perfume’ and to perfume gloves’. (ff. 94, 85, 31, 98).

What many of the recipes have in common is that they were designed to transform the skin rather than cover it. Even hand ointments had a higher purpose, not just removing blemishes; keeping hands soft avoided drying and cracking, and becoming susceptible to disease. Protecting and preserving the skin was central to beauty.

Oyle of talcum, Margaret Baker, Folger Shakespeare Library V.a.619, f. 21.

Many of the recipes required extensive time, skill, and effort to prepare. Baker included a powder recipe is for ‘oyle of talcume’ (f. 21), which was labourious to make. At one point in the process it needed to be let down by a rope

into a well some yard & a halfe or two yardes from the water nere to the well soe it touch it not’ & soe let it hang .20. or. 25. daies then if you find that it begine to cast out some oyle take it out of the well & set it in some moyst place, in some corner of your seller to defend it from the ayre: wind or other harmes & soe leaue it soe longe untill all the liccor become out of it.

The result was powder that could be mixed with water to wash the hands and body, making ‘them very white, soft and free from freckles or spottes – good for ladies’.

An alchemist in his laboratory. Oil painting by a follower of David Teniers the younger,. c. 1610-1690. Credit: Wellcome Library, London.

Sometimes, the connections between alchemy (or chemical medicine) and beauty were literal. Baker used mercury in both her medicinal recipes and beautifying physic. This was not just an ingredient. Its knowledgeable deployment put Baker within the (assumed) masculine spheres of medicine, surgery and alchemy. Throughout her book, there are clues that Baker read widely on medicine and alchemy.

But the connections between alchemical transformation and bodily protection are clearest in beauty recipes. For example, in relation to one particular beautifying physic (f.12v.) it appears that Baker is attempting the impossible. An anomaly arises in the title ‘the taking away ‘quicksilver from mercurie’–the Oxford English Dictionary indicates that mercury and quicksilver are in fact the same. However, it seems that Baker may have been aware of cutting-edge experiments. Natural philosopher Robert Boyle, Baker’s contemporary, explained that through a system of depuration or continuous distillation and reduction, common quicksilver will run from the purified form of mercury left behind, which is then suitable for more sophisticated use (Boyle 645). In Baker’s case she is able to produce a ‘perfect water to keep the face cleare from spots or wrinkles.’

Baker’s recipes reveal her intellect and interaction with ideas of the day, as well as point to the uses of beauty treatments: transforming one’s body chemically and alchemically.  Bodily transformations included protecting and beautifying the skin, or even enabling social elevation.  Beauty and alchemy sat close together in Baker’s book.