‘Follow what I say’: Isabella Cortese and Early Modern Female Alchemists

How would you go about learning alchemy? Well, I would start by making a list of alchemists whose work I should read. Then, I would do a lot of reading. That might seem unimaginative – and it is – but, for centuries, that’s how people learned alchemy. Of course, they would eventually go to their laboratories or kitchens and try things out in practice. But reading was essential. So, it was a break with tradition when alchemist Isabella Cortese wrote in her book that

If you wish to follow the alchemical art, and practise it, you must stop studying the works of Geber, Ramon [Lull], Arnaldo [de Villanova], and other philosophers, because they said nothing truthful in their works except through images and puzzles.’
I Secreti della Signora Isabella Cortese, Venice, 1561

But let’s back up a bit. Who was Isabella Cortese? Well, the short answer is… We don’t know. Not really, anyway. One of the best-selling recipe books of the early modern period was attributed to her, but it is (very) likely that she was a fictitious character created by the publisher Giovanni Bariletto. In her book, Cortese described herself as a noblewoman who spent decades travelling and studying alchemy, gathering the recipes (‘secrets’) published in the collection. She argued against book learning: alchemy had to be learnt in practice. And that could be done at home: women should embrace ‘kitchen alchemy’.

Unfortunately, we have few clues about her besides what’s written in her book. Trust me, I’ve been looking for her in archives and libraries for almost a decade now, which is why I am convinced she was an invention. Yet, she was clearly inspired by great women alchemists of her day, such as Caterina Sforza and Isabella d’Este (might her name come from this Isabella?). It’s also intriguing that her last name, Cortese, is an anagram for ‘secreto’ in Italian. But ‘cortese’ also evokes nobility and wealth – it literally translates as ‘courtly’. Furthermore, the recipes were addressed to ‘every great lady’, highlighting how the work was gendered.

The book itself contained medical, alchemical, cosmetic, and veterinary recipes. In the early modern period, there was much overlap between these spheres, and books like Cortese’s had recipes for virtually anything. It might seem striking to us that formulas to treat baldness or remove stains from clothes appeared side by side with ways to prolong life (the elixir famously known as the ‘philosopher’s stone’) or to turn base metals into gold. Yet that was typical of recipe books of this period: what connected the recipes was the focus on practical instructions rather than theoretical explanations. Cortese was interested in how to make phenomena occur, not so much ‘why’ they happened.

Her collection also included many recipes about reproduction and the female body, such as advice on pregnancy and menstruation, hinting again at a female readership. Among the hundreds of recipes, there were many cosmetic formulas, which were chiefly prepared and used by women, even queens such as Elizabeth I. This is a typical entry:

Beauty Water for the Face: Take lemons and dried beans and combine them in white wine; add honey, egg, and goat’s milk, and distil it all together; and this water will make the face beautiful.
I Secreti della Signora Isabella Cortese

These recipes could be produced at home, in a domestic alchemical laboratory – in other words, a well-equipped kitchen. Therefore, this unique recipe book was doubly gendered: it was attributed to a woman and addressed to female readers. And what did Cortese tell them?

Cortese urged readers to stop reading the great alchemical masters of the past. Who should aspirant alchemists follow, then? As she wrote in the book’s dedication to her brother:

I ask you [dearest brother] not to waste your time with these books by philosophers but follow what I write for you, and do not omit or diminish anything, but do instead what I tell you and write [for you], and follow my instructions below.
I Secreti della Signora Isabella Cortese

Cortese’s brother – and her readers – were not to deviate from her orders. So, if at a first glance it may seem that Cortese is breaking with tradition by suggesting that alchemical adepts experiment by themselves, a more attentive reading shows that she is replacing one kind of authority with another: study gave place to experience. Instead of great men, who taught through theory, readers should follow great ladies, such as herself, who would teach them through practice. Her ‘new alchemy’ was an everyday pursuit open to everyone, regardless of their sex. Cortese invited lay women to directly engage in alchemy as her apprentices: ‘every great lady’ could be an alchemist, from their own kitchen.


Isabella Cortese, I Secreti della Signora Isabella Cortese (Venice: 1565).

Further Reading:

William Eamon, Science and the Secrets of Nature: Books of Secrets in Medieval and Early Modern Culture (Princeton: Princeton University Press, 1994).

Meredith Ray, Daughters of Alchemy: Women and Scientific Culture in Early Modern Italy (Cambridge MA: Harvard University Press, 2010).

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Caterina Sforza: Using All the Weapons in Her Arsenal

Some historical anecdotes are just irresistible. This is one of my favourites.

After her husband was assassinated and she and her children were taken prisoners by their political enemies, Caterina Sforza (1463-1509) found herself in a precarious position. The conspirators wanted to take control of the castle in Forlì, yet the people inside, loyal to Caterina, did not want to surrender. Leaving her children as hostages with her enemies, Caterina promised she would enter the fortress and make sure it surrendered. So, the conspirators let her go. Which mother would let harm befall her children, after all? Yet as soon as she was inside, Caterina started to threaten her enemies, promising violent revenge. But what about her children, you may ask? Caterina lifted her skirts, showing her genitals to her enemies and, pointing towards her vulva, stated that she could always make more children.

This tale is, of course, a bit too theatrical to ring true. It was told by many contemporaries, however, starting with Niccolò Machiavelli, who mentioned it in The Prince and wrote about it at length in The Discourses (Chapter III). It’s possible that he was inspired by earlier writings (both Herodotus and Plutarch described skirt-raising episodes), but what I’m interested in is what this story tells us about how people saw Caterina. Machiavelli had met her in person several times as a Florentine ambassador, as Caterina became regent of Forlì and Imola, in the Romagna region of Italy. It’s clear in his writings that he greatly admired her, her strength, and her political skills.

Other contemporary sources depicted her as fierce, brave, and clever. And with good reason: Caterina Sforza was one of the most incredible people of her time. She occupied Castel Sant’Angelo in Rome after the death of Pope Sixtus IV, and she bravely resisted military attacks by Cesare Borgia. She was even later accused of having poisoned his father, Pope Alexander VI, and was imprisoned for a while. This was not an implausible accusation: as many noblewomen of her time (including her descendent Catherine de’ Medici), Caterina knew a thing or two about poisons.

Yet discussions about Caterina often neglect this crucial aspect of her life: her experiments with alchemy, medicine, and cosmetics. Her manuscript recipe book Experimenti(Experiments) counted 454 formulas, compiled throughout her lifetime. These included panaceas, the philosopher’s stone, recipes to protect the body from disease, poisons and their antidotes, and even a way to bring the dead back to life. See what I mean about Caterina being a fascinating person?!

An interest in scientific experimentation and collecting recipes was not rare among aristocratic women of the time, although there were few so well-known or respected as Caterina. She spent most of her life collecting recipes from all kinds of sources: written and learned texts, vernacular traditions and oral cultures, and her own empirical practices.  Her contemporaries were also important sources of knowledge, be they people from low social status (including from marginalised communities, such as Jews) or aristocratic backgrounds, with whom she corresponded. Many of these recipes concerned the secrets of women: menstruation, childbirth, and lactation were all subjects she was interested in. Several recipes were protected from prying eyes, written in Latin, and encrypted, such as alchemical formulas and treatments for impotence and lack of libido in men. Thankfully, the code has survived along with the manuscript recipes, so we can read everything today!

Caterina’s knowledge was not only theoretical. She designed gardens in which she could grow medicinal herbs and plants to use for cosmetic formulas. She had a close relationship with convents, and nuns involved in the preparation of medicines. These women exchanged recipes and ingredients from their respective gardens. And this was a key aspect of Caterina’s life and how she managed to use her empirical knowledge to further her political aims: she created networks of relationships, based largely on the exchange of recipes.

People sought and wrote to her asking for her famous recipes, which she used as currency. She corresponded with Lorenzo de’ Medici and Isabella d’Este, another noblewoman who collected recipes, most notably for perfumes. Caterina established alliances with men and women through the exchange of recipes and marvellous secrets. Her 19th-century biographer, Pier Desiderio Pasolini, described her work as themost complete and known’ medical text of the 16th century. That’s not surprising. Not only did she compile hundreds of recipes, but some of them made unique promises. Her Elisir vitae (elixir of life) could make ‘a person regain their youth and bring the dead back to life. If someone was so ill that even physicians had abandoned them, [the elixir] will restore them to health.’ She even had a recipe for an anaesthetic using opium to put patients to sleep (though I haven’t found any evidence of it having been used in surgeries). She was also famous for her poisons and invisible ink formulas (both useful for courtly life, for getting rid of enemies and for keeping written communication secret).

Caterina was also a source of knowledge about cosmetics. She was herself described as a beauty, as seen in her portrait by Lorenzo di Credi (1459-1537). Her formulas to attain the female beauty ideal of the time included ways of making the skin pale, the hair blond or ginger, and the breasts small. (All of them were characteristics Caterina embodied.) In a recipe addressed to women and girls, she wrote:

‘Take hemlock juice and use it daily. Even if [the breasts] are large they shall become small […] if you are still girls, and have not matured, if you use this [formula] every day they [your breasts] will not grow larger and will remain beautiful and firm.’

As the grandmother to Cosimo I, the first Grand Duke of Tuscany, Caterina played a key role in the development of early modern science. She left her recipe collection to her son, and it remained in use within the Medici family for generations. So, if the skirtraising incident told by Machiavelli depicts Caterina as a masculine, unnatural mother, her scientific work shows a different side of her, as an ‘empirical mother’ at the origin of a long involvement with medical, alchemical, and cosmetic experimentation on the part of the Medici and their court.

Caterina used all her skills as tools to further her political goals. But she also weaponised her knowledge about the natural world and the human body. By exchanging recipes (most notably through her epistolary network), she cemented diplomatic, political, and social connections. Many women of the period used medical recipes within their households, to take care of their families and communities. Caterina went beyond the private uses of recipes, employing them as a form of currency in the political and medical economy of the period. Her recipes became a way of managing power and influence, and, to Caterina, they were a central part of her life. She never stopped collecting recipes for transforming metals into gold, pursuing beauty, and returning the body to health. In doing so, Caterina illustrates the role Renaissance women played in the scientific investigation of the natural world. Regardless of having raised her dress or not at her befuddled enemies, she was someone remarkable.


Jacopo Filippo Foresti da Bergamo, De plurimus claris selectisque mulieribus (Ferrara: Lorenzo Rosso da Valenza, 1497).

Pier Desiderio Pasolini, Caterina Sforza (Rome: E. Loescher, 1893).

Caterina Sforza. Experimenti de la s.ra Caterina da Furlj, edited by Paolo Aldo Rossi (Arenzano: Castel Negrino, 2018).

Further Reading:

Elizabeth Lev, Tigress of Forli: The Life of Caterina Sforza (London: Head of Zeus, 2018).

Meredith K. Ray, Daughters of Alchemy: Women and Scientific Culture in Early Modern Italy (London: Harvard University Press, 2015).

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