Wednesday, March 22, 2017

Aventurine

Small amphora in aventurine glass ”
Murano, Salviati.
With all its glitz and sparkle, aventurine (avventurina) stands out as a flamboyant extrovert among the varieties of glass that were developed and perfected on the Venetian island of Murano. Also known as 'goldstone', it consists of a transparent base glass with myriad reflective crystalline "spangles" running throughout. The classical version is a deep golden brown with crystallites composed mainly of metallic copper, with a few related compounds as supporting cast. However, numerous colors have been developed, including red, orange, yellow, green, blue, violet, black and white. 

Folklore holds that aventurine was discovered by accident ("a venturi") when unknown monks inadvertently dropped copper or brass shavings into a glass melt as early as the thirteenth century. [1] However, more thorough investigations have recently identified 1620 as a likely date for the first appearance of aventurine glass. [2] No example or written account has been found that dates prior to the seventeenth century. An alternate story accounts for the name aventurine being derived from 'adventure'; referring to the difficulty and uncertainty involved in its production.[3] At first, the formula was a closely held secret among a few glassmakers and subsequently it was lost and then rediscovered not once but  twice.

To complicate matters, natural minerals with a similar appearance were named after the glass, leading to the misconception that they were also discovered after the glass was invented. This is clearly not the case. Early examples of mineral aventurine artifacts date to the Neolithic era [4] and can be found throughout history. First century Roman writer Pliny mentions a type of stone with silvery flecks, a passage that was well known when the glass was developed.  The compositions of these minerals were also identified early; either species of quartz that contain flecks of mica, or a type of feldspar (sunstone).[5] Mineral aventurine turns up as the eyes of Greek statues, in stonework mosaics and later in the 'pietre dure' art perfected by the Medici artisans in Florence around the time Antonio Neri started making glass there. The chances are good that examples of the mineral were known to Neri as well as to the glassmakers on Murano, but a recipe for the glass version does not turn up in Neri’s 1612 book; he was apparently too early by a decade.  

The story of aventurine's accidental discovery by monks may well be apocryphal; nevertheless, it is a great entrée to understanding how the formulation works. First, contrary to what the story implies, aventurine is not the result of dumping metallic confetti into glass. The reflective "spangles" (as early researchers were fond of calling them) are actually uniformly sized, mirror-like crystals that are grown in the glass. In truth, the formula is quite similar to recipes already in use by Neri and others; the difference was in proportions and in how the glass was treated after it was in the furnace. The formula for aventurine calls for the addition of copper, iron and tin oxides, to a base that was a hybrid of soda, potash and lead glass. Neri’s recipe #128 is titled "A Proven Way to Make Rosichiero" [6] and provides for all of these ingredients, albeit in lower concentrations. Rosichiero was a transparent tawny red colored glass that was a staple of furnaces throughout Italy. 

The secret to producing the reflective "spangles" was to mix the glass and heat it in the furnace in a normal way, but then to slowly reduce the heat while creating a low oxygen “reducing” atmosphere. The furnace draught was shut; the glass pot was fitted with a tight lid and then covered with ashes and allowed to cool very slowly.  

Initially, the batch is saturated with copper oxide. This means the glass has dissolved as much copper, iron and tin as it can and any further addition of these powders will simply float to the bottom of the pot.  The exact amount of powdered metals able to dissolve is a function of temperature; the hotter the glass the more that will dissolve and the cooler the glass the less that will dissolve. The key concept here is that as the glass slowly cools, the metals start to come out of solution and crystals start to form. There is some complex chemistry happening at the same time; the reducing atmosphere encourage the metals to stay in a pure un-oxidized form,  Furthermore any oxygen or sulfur  that happens to be present will preferentially combine with the iron, leaving the copper crystals pristine. Once cooled to room temperature, a successful batch would be broken away from the glass pot by workers and divided into smaller pieces. Glass artisans wanting to incorporate the aventurine into their work needed to work quickly. They carefully reheated an appropriate nugget and coated (encase) it in a layer of clear glass; once molten, direct exposure to the air would destroy the glittery effect. 

Over time, it was discovered that various colors could be produced with the addition of different chemicals, but the central principal of growing tiny metallic crystals is the same.


[1]  The earliest instance of this story in print that I can find is fairly late;  Faustino Corsi, Delle pietre antiche: libri quattro (Rome: Salviuccio e figlio, 1828)  pp. 166-167.  
[2] Cesare Moretti (†), Bernard Gratuze and Sandro Hreglich,  “Le verre aventurine (‘ avventurina ‘) : son histoire, les recettes, les analyses, sa fabrication”, ArcheoSciences, 37 | 2013, 135-154.
[3] For instance see  Giulio Salviati, “Venetian Glass” Journal of the Society of Arts (Proceedings), Volume 37 (7 June,1889), p. 630
[4] Neolithic Quartz Aventurine Pendant - 7 Cm/ 2. 76 ", green - 6500 To 2000 Bp – Sahara. Item Id: 106549,  Weight: 83 gm. Sahara - Mauritania - Tagant country.
http://ancientpoint.com/inf/106549-neolithic_quartz_aventurine_pendant___7_cm_2___76____6500_to_2000_bp___sahara.html
[5] Dizionario del cittadino, o sia Ristretto storico, teorico e ..., Volume 1 pp. 38-39.
[6] Antonio Neri, L'Arte Vetraria (Firenze: Giunti, 1612).
[7] Sauzay, A. (1870) Marvels of Glassmaking in All Ages. London, 1870 pp. 173 - 175.

Monday, March 20, 2017

Arminia Vivarini

Nef Ewer, Late 16th century, Murano Italy.
Courtesy Milwaukee Art Museum
On the afternoon of Friday, 22 March 1521, The Venetian Senate - then called the ‘Pregadi’ - reconvened after lunch. Senator Marino Sanuto (the Younger) recorded in his now famous diary that among the afternoon business was the granting of a ten year exclusive license to Arminia, the daughter of painter ‘Alvise da Muran’ (Luigi Vivarini). She was granted this privilege to produce the ornamental glass galley ships she had recently devised. [1,2] Once called 'Navicella' (little ships) these ewers, probably most used to serve wine, are now known as ‘nefs’. A pour spout was situated at the ship's bow, and often a handle astern. These objects soon became iconic symbols of the island-nation’s long dominance in trade, and regularly appeared on sideboards and elaborate dinner table settings, not only in the lagoon, but in Florence, Rome and far beyond.


In their Objects of Virtue: Art in Renaissance Italy, Syson and Thornton write,
“It was not only the use of coloured canes in complex patterns embedded into clear glass that typified Venetian glass from the 1520s, but also the manipulation of cristallo into ever more fantastic forms. Novelties were first displayed at the Ascension Day Fair, which, like visits to the glasshouses in Murano itself, was firmly on the tourist map by about 1500. The Venetian diarist Marino Sanuto mentions the work displayed at three booths at the fair in 1525, those of Barovier, Serena and Ballarin workshops ‘among other things, a galley and a very beautiful ship were to be seen.’”
Syson and Thornton continue, “Leandro Alberti singled out just this kind of glass in his famous description of the marvels of Murano in his Description of All Italy of 1550: ‘I saw there (among other things made of glass) a scaled-down model of a galley, one braccia long and with all its rigging and equipment, so perfectly in scale that it seemed impossible to model such things accurately in such a medium.” [3]


Scholar and science investigator, Georgius Agricola, described a vessel in the form of a ship in his De re metallica published in Basel in 1556,
“The glass-makers make diverse things, such as goblets, cups [...] and ships, all of which excellent and wonderful works I have seen when I spent two whole years in Venice some time ago. Especially at the time of the Feast of the Ascension they were on sale at M[u]rano, where are located the most celebrated glass-works. These I saw on other occasions, and when, for a certain reason, I visited Andrea Naugerio in his house which he had there, and conversed with him and Francisco Asulano.” [4]


Arminia Vivarini’s father was a painter of some renown, but her family is also among the earliest recorded glassmakers on Murano. Her third-great grandfather, named Vivarino, arrived from Padua, just ahead of the plague in 1346. [5] The family seems to have been involved in the craft on the island from then on. She clearly had access to a furnace, perhaps one owned by an uncle or a cousin. In any event, she exemplified the qualities of the very best glass artisans throughout history: a clear design sense coupled with technical expertise and the opportunity to put them both into practice.


Her very existence also forces us to more closely examine the well worn narrative that hot-shops were exclusively male domains, from which women were strictly excluded. In such a highly competitive arena, it is perfectly reasonable that a family would promote its best talent, regardless of gender. In many ways, we owe homage to Vivarini for her success with this style of novelty glass object; it started the genre that continues in popularity today, five centuries later, with works of art prized by collectors and in museums around the world. [6]


[1] Arminia  (Armenia, Ermonia) Vivarini (1490-1569). See Luigi Zecchin: Vetro e Vetrai di Murano, 3 vols. (Venezia: Arsenale, 1987-9) v.3, p. 194.
[2] Marino Sanudo: I diarii di Marino Sanuto (1466-1536)  v.30. Eds., F. Stefani, G. Berchet, N. Barozzi (Venezia: Fratelli Visentini, 1891) col. 45. Also see Zecchin 1987-9, v.2, p.276.
[3] Luke Syson, Dora Thornton: Objects of Virtue: Art in Renaissance Italy (Los Angeles: J. Paul Getty Museum, 2001), p. 197.
[4]  Georgius Agricola (Georg Bauer): De Re Metallica: Tr. from the 1st Latin Ed. of 1556… trns: Herbert Hoover, Lou Henry Hoover. (Princeton: Mining Magazine, 1912), p. 592 (Book XII.)
[5] op. Cit. Zecchin 1987-9, v.3, p194-5.
[6] Thanks to Sophie Small‏ @sophieesmall for inspiring the subject of this post.

Friday, March 17, 2017

Rise and Fall

"Merry Company," (1623)
Gerard van Honthorst
The first decade of the seventeenth century was a golden era for glass in Tuscany. The Venetian techniques brought to the region by Grand Duke Cosimo de' Medici in the 1570s had been assimilated. The pioneering work of his son, Francesco, in cross pollinating different crafts under one roof, was by now bearing fruit in unique items that included the handiwork of glass artisans. Grand Duke Ferdinando understood the value of glass as a source of prestige and was willing to invest in it. This was the environment in which Antonio Neri first learned to make glass. Delicate drinking glasses were the toast of the aristocracy throughout Europe. The material was critical to the advancement of chemistry, medicine and by the end of the decade astronomy. 

In 1602, Antonio Neri came to work in the shop of Niccolò Sisti in Pisa. While Sisti was making fancy glassware for the Medici court, the nearby Coscetti firm was supplying Pisa with everyday items. Coscetti made glassware for private homes, but also innkeepers, spice and perfume sellers, winemakers and a baker among others. Their wares included cruets for oil, saltcellars, carafes, drinking glasses, containers for holy water, reliquaries, gilded Venetian style cups and English style flasks. 

By the second decade, momentum started to shift and before long, the glass industry in Tuscany fell on hard times. Apparently the demand for glass could not support the number of factories that had started and the rapid succession of leadership in the duchy added uncertainty to patronage of the arts in general. 

Another factory in Pisa was run by Giovanbattista Guerrazzi, who had acquired the exclusive right to make Venetian style cristallo from Neri's old employer Sisti. In 1623, Guerrazzi had problems of a different sort, not directly related to the sales of glass. He appealed to Pisa’s Office of Rivers and Ditches, pleading with them to modify a recent ruling. He explained that he owned three houses next to his furnace, one for his family and the others functioning as sales space and housing for his workers. Since he was the exclusive maker of cristallo, he had employed a number of girls and women to decorate the delicate glassware, and a constant stream of the nobility showed up to watch the work being done. Guerrazzi's problem was that the Magistrate of Public Decency had recently published a list of seven places where women of "ill repute" were allowed to stay. One of these was located next door to his glassmaking operation. He begged for a change in the ruling, to move his new neighbors elsewhere.

The outcome of his appeal is not known, but Guerrazzi was succeeding in the glass business, and at the same time accelerating the demise of his competitors. He bought-out and demolished the furnaces of a number of other glassblowers and planned the same fate for the Coscetti operation, putting all the craftsmen there out of work. In the mid 1620s, after a quarter century of operation, the fires under Coscetti furnace were allowed to go out forever. Furnaces at Leghorn, Pistoia and Prato had shuttered, leaving only the one furnace in Pisa, two in Florence and two at the castle of Montaione. 

*This post first appeared here on 12 Dec 2013.

Wednesday, March 15, 2017

The Neri Sisters

Portrait of the Egerton Sisters
(no relation to Neri)
English School,  c. 1601-1602
Among the ten children born to glassmaker Antonio Neri’s parents, three of them were girls; Lessandra, Maria, and Lucrezia. Because women were not allowed to legally own property, or sign contracts many of the usual sources of information are silent. Most of what we can learn about them is through their relationships with the men around them.

The Neri's were a patrician family, and the children enjoyed a very comfortable existence for the late sixteenth century. There is evidence that all three sisters survived into adulthood. Lessandra was the first-born, nine years older than Maria, and twelve years older than Lucrezia. 

When Lessandra was around age seventeen, her famous father, Neri Neri, was appointed as personal physician to the newly crowned Grand Duke Ferdinando de’ Medici. However, only a few short years later their mother Dianora died at age 42, of causes that are unknown, perhaps childbirth. The girls were 22, 13 and 10. A few short years later they lost both their father, and a brother.

Two information sources for the Neri sisters are their birth records kept at the Opera del Duomo and genealogy records for the family which are filed at the National Archives, both in Florence. The baptism records hold a wealth of indirect material through the names of their godparents. While these do not tell us anything specific about them, it does tell us who their influences were; who they looked to for strength and spiritual guidance, under the circumstances, this is the best we can do. 

Lessandra (b. 1572) claimed Baccio Valori as her godfather. The Valori family had a long, tragic history with the ruling Medici family. His father, grandfather and great-grandfather were all close Medici supporters, yet each ended up exiled, imprisoned, or executed after relationships soured. On one hand he was faithfully employed by the Medici, yet he reportedly spent a good deal of his time collecting letters and papers documenting his family’s close support of Girolamo Savonarola, the firebrand Dominican priest who lead Florence in the late 1490s, after the Medici had been temporarily expelled from the city.   

Lessandra’s godmother was Marietta Gaetani, also from a noble family, which included dukes, cardinals and popes. They played prominent roles in the politics of Pisa, Rome and Naples for several centuries. Marietta’s father owned the house from whose tower Galileo showed the moons of Jupiter to Grand Duke Cosimo II in 1610.

The genealogical records imply that Lessandra later took vows with the S. Agata monastery on the North end of Florence and took the name suor Emilia. The facility was located in a district devoted to care of the sick and infirmed.

Maria’s (b. 1581) godfather was Monsignor Giovanni Alberti. Giovanni was the son of a Florentine senator. He served as protonotary apostolic for Pope Gregory XIII and as bishop of Cortona under Pope Clement VIII. A godfather serving in the papal inner chambers was a good family contact indeed. Also appearing for Maria was Pierfilippo Perini, a physician and lawyer. The Registri lists Maria Neri's godmother as Alessandra di Girolamo Pepi. Among the prominent Florentine republicans was Alessandra's father, Girolamo. He was tortured by Alessandro de' Medici in the 1530s, upon the family's regaining control of Florence after the siege.

The genealogy indicates that she married into the Boscoli family, but further work is needed to identify a specific individual.



Lucrezia (b. 1584), the youngest Neri girl, has a single godparent listed in the register, Montiglio degli Albizi. The Albizi family boasted powerful bankers and politicians. This was another case where deep divisions over Medici rule drove a family apart. Perhaps the best-recognized member of the Albizzi family was Eleonora degli Albizi. She was the young consort of grand duke Cosimo I. Folklore has it that in 1566, Cosimo intended to retire from public life and marry Albizi quietly, after the birth of a girl, but his regent son, Francesco I, forbade it to due to the inheritance complications that would ensue. The story is that Cosimo's long-time personal secretary, Sforza Almeni, leaked word of the clandestine marriage to the family. For his betrayal, an enraged Cosimo murdered Almeni in cold blood. Eleonora later gave birth to Don Giovanni de’ Medici, the uncle and friend of Don Antonio, Neri's sponsor. The specific Albizi family member we are interested in, Lucrezia's godfather, Montiglio degli Albizi, seems to have eluded history. Lucretia married into the Talenti family, but no further details are known.

Monday, March 13, 2017

Dianora Parenti

Agnolo di Cosimo 'Bronzino',
"Portrait of Florentine Noblewoman"
(subject unknown , circa. 1540).
The mother of Antonio Neri, the 17th century glassmaker and alchemist,  was named Dianora Parenti. She was the oldest of six children: three girls and three boys. She was born in Florence, on 11 February 1552, with the given name of Dora listed in the city's baptistery register. In all probability by the age of eighteen she was quite accustomed to helping her mother with the other children; Caterina, the youngest, was born less than a year before Dianora's wedding.

Her father and grandfather were prominent lawyers; together they handled much of the personal business of famed artist Michelangelo. On the 20th day of August 1570, Francesco Parenti walked his eldest child down the aisle to be joined, in holy matrimony, to physician Neri Neri. Two years later, their first child Lessandra was born. 

Historians Luigi Zecchin and Enzo Settesoldi identified four of Antonio's brothers, two older and two younger. They were Jacopo (1573), Francesco (1575), a second Jacopo (1577) and Vincenzio (1579). In addition to these five boys, there were at least two more brothers born later, Emilio (1583) and Alessandro (1587). And there were at least three girls, the first-born child Lessandra (1572) and two younger sisters: Maria (1581) and Lucretia (1584). 

In all, there were ten births by Dianora recorded in Florence, occurring almost like clockwork on a fifteen-month schedule. As did many women of the period, she spent a significant portion of her adult life pregnant. In her case, it was a span of sixteen years, carrying one child after another with minimal interruption.

The birth of a child in Renaissance Florence was no small occasion. Patrician families went to considerable expense on decorations, on food and drink for guests and on gifts for the mother and godparents. "The woman who gave birth, like a bride at her wedding, occupied for a passing moment a position of unparalleled honor,"* more than that, while a wedding signaled the transition from daughter to wife, the birth celebration was a rare social recognition of a woman as an individual.

A genealogical record of the eighteenth century, held at the State Archives in Florence (ASF), confirms most of the Neri children's births. It also sets the date of death for their mother Dianora at 1594 when she would have been forty-two years old. This means Antonio lost his mother when he was eighteen and his youngest brother Alessandro was a mere seven.

* Margaret L. King, Women of the Renaissance (Chicago: University of Chicago Press, 1991), p. 4.

This post first appeared on 11 September 2013.

Friday, March 10, 2017

Kitchen Alchemy

Tesoro del Mondo, "Ars Preparatio Animalium"
Antonio Neri 1598-1600, f. 10r (MS Ferguson 67).
Between 1598 and 1600, Antonio Neri wrote a manuscript filled with alchemical recipes. He entitled it Tesoro del Mondo or "Treasure of the World" and stated that it was a book in draft form, intended for publication. It never did see the ink of a printer's press, but Neri's original handwritten version did survive intact and today occupies a place of pride in the Ferguson Collection of the University of Glasgow Library. [1]

Tesoro is an ambitious work, devoted to "all of alchemy," containing numerous hand-drawn ink and watercolor illustrations; some of the pictures are allegorical, many others document practitioners working with equipment. Only passing reference is made in this manuscript to glass—its most notable appearance is as experimental vessels. 1598 was two or three years before Antonio's glassmaking career is thought to have started. His life was busy on other fronts. He had just been ordained as a Catholic Priest, undergoing the laying on of hands ceremony, probably by his neighbor on Borgo Pinti, the Florentine archbishop Alessandro Ottaviano de' Medici. 1598 was also a year of tragedy for the Neri family; by the summer, his father Neri Neri, personal physician to the grand duke, died of an unknown illness, but not before making arrangements for his family, which included a will. A court magistrate would oversee the now orphaned children's education, inheritance and dowries. They would soon suffer further tragedy in the unexpected death of a brother; sixteen year-old Emilio would leave them on Christmas day of the following year, in Castello outside Florence. 

The losses must have been devastating. In 1598, five of the nine children were still under the age of twenty. Without a mother or father, great responsibility must have fallen on the shoulders of the matriarch of the house, the children's elderly paternal grandmother Maddalena. [2] Even though the Neri's were a wealthy and quite well respected family, these events undoubtedly threw their lives into turmoil. It is in these circumstances that Antonio started his manuscript. The tragic events allude to the reasoning behind a cryptic Latin quote scribbled at the top of a page above the first recipe: "fuimus troes." It means, "We are Trojans no more" From Virgil's Aeneid, referring to the fall of Troy. [3] 

Early in the manuscript there is a series of four illustrations, each showing a different activity, In order, they are titled The Art of Preparation of Stones, Metals, Plants and Animals. [4] Each is filled with multiple workers engaged in various activities pertinent to the specific art. Each highlights interactions between the Aristotelian elements: air, water, earth and fire. There is no specific indication of where any of the four scenes take place, although some educated guesses can be taken. For instance, the stone workers, or lapidaries, almost certainly are an early incarnation of the famed 'Opificio delle pietre dure' working in the Uffizi's Galleria dei Lavori. But we will leave that discussion for another time. 

Of the four illustrations, "Preparing Animals" focuses on activity within a kitchen. (See above, click to enlarge). The scene is intriguing in that it appears to take place in a domestic setting. It is also remarkable for featuring women at work. Labels call out the four Aristotelian elements; birds hanging from the rafters represent air, fish on a grilling rack represent water, a whole carcass on the spit represents earth and fire appears as itself in several locations. It is not unreasonable to suggest that this setting is none other than the Neri family kitchen and that the practitioners of the art are three of Antonio's siblings. In the middle right, a young boy is engaged in turning the spit (in green). The best candidate would be then eleven year-old Alessandro, the eventual heir to the family, whose own son named Neri would carry on the family practice as a physician. Of the two young women pictured, the three family choices are fourteen year-old Lucretia, Sixteen year-old Maria and twenty-six year-old Lessandra.

In addition to preparing finished meals, seventeenth century kitchens were busy making more basic ingredients also; preserves, distillations, special salts, herbal extracts and so forth. In addition to foods, medicinal and hygienic products were produced, like syrups and soaps. There is another strong connection between the kitchen and alchemy that lives on today: the methodology of cooking. The process of combining raw ingredients and cooking them together, of experimentation and of iteratively refining a recipe to perfection, this is not so different from what Antonio Neri and his siblings were doing four hundred years ago.


[1] Neri 1598-1600.
[2] Maddalena di Bartolomeo di Niccolò Bartoloz[z]i, married Jacopo Neri, and they gave birth to Antonio’s father Neri Neri. (ASF 599).
[3] Fuimus Troes, fuit Ilium, et ingens Gloria Teucrorum. [We Trojans are at an end, Illium has ended and the vast glory of the Trojans], The Aeneid: Book 2, Line 325.  See also the post in this blog (Conciatore.org) dated 13 June 2014.
[4] Neri 1598-1600, ff. 7r, 8r, 9r, 10r.
* This post first appeared here on 27 August 2014,

Wednesday, March 8, 2017

Caterina Sforza

Caterina Sforza, by Lorenzo di Credi
(now in the Museum of Forlì.)
We remember Antonio Neri mostly for his book on glassmaking, L'Arte Vetraria. However, he thought about himself a bit differently; he considered himself first and foremost an alchemist. This interest can be traced to at least two generations before him; his father, Neri Neri, was an acclaimed physician – in fact, the personal physician to Grand Duke of Tuscany, Ferdinando I de’ Medici. Antonio's grandfather, Jacopo Neri, was a barber-surgeon. Both of these professions required an extensive knowledge of herbal distillation and other techniques which are shared by alchemists.

Antonio's benefactor, Don Antonio de' Medici, also followed a family passion for the chemical arts, in his case, traceable through an unbroken chain, to a female alchemist, his great-great-grandmother, Caterina Sforza, (c.1463–1509). After her death, over four hundred of her formulas were passed down to her son, Giovanni dalle Bande Nere, then to his son Grand Duke Cosimo I de' Medici, Grand Duke Francesco I, and finally to Don Antonio. 

Caterina was the illegitimate daughter of the Duke of Milan, Galeazzo Maria Sforza, but was still educated at court, and apparently 'apprenticed' apothecary Ludovico Albertini. At age fifteen, she was married to a nephew of Pope Sixtus. The pope granted her title of Countess of Forlì and Imola. After her territory was later taken and her husband murdered (by a faction of their own people), she escaped prison and retook the two cities. In 1495, when her second husband was assassinated, she launched a campaign which gutted the families of the murderers. Her third husband was Giovanni de' Medici, and their son, named after his father would become a brilliant military strategist, like his mother. His own son, Cosimo, would later become the first "Grand Duke" of Tuscany. 

Her chemical recipes were transcribed in 1525 by a captain in her son's army, Count Lucantonio Cuppano da Montefalco, and ultimately published as a book in 1893 (Pasolini). Included are an assortment of formulas which range from cosmetics, to medical remedies, poisons and alchemical concoctions.
Researcher Jacqueline Spicer writes:
Lost among the romanticized military conquests is a thorough account [of] the project that occupied several years of her life—the manuscript of her alchemical and medical experiments and recipes titled Gli Experimenti de la Ex.ma S.r Caterina da Furlj Matre de lo inllux.mo S.r Giouanni de Medici, or Gli Experimenti. The text is an early example of what would later become the popular medical genre of "Books of Secrets", but is so early that it does not appear in most modern writing on such books. Furthermore, Gli Experimenti is unusual because it was written by a woman in an otherwise male dominated genre, and unique in that we know a great deal about the life of its author.[1]

Among the alchemical entries are "to convert pewter into silver of the finest quality and of standard alloy," a method "for giving to bars of brass a fine golden color" and another for "for multiplying silver." Also, there are ways described  to "make iron hard," "to dissolve pearls" and "to dissolve all metals." In the medicinal category, we find "for infirm lungs, an ointment is to be made of the blood of a hen, a duck, a pig, a goose, mixed with fresh butter and white wax." This was to be applied to the chest with a fox's skin.
Sandro Botticelli, Primavera (1498)
(detail - rightmost of the three graces)

Caterina Sforza was painted many times and often depicted as the Virgin Mary, a typical trope for the nobility at the time. She may have been immortalized  by Sandro Botticelli as the rightmost of the three graces in his Primavera and as the main subject in The Birth of Venus.[2] Reportedly, she was the subject of ballads and sonnets, although most have been lost. She is a topic of discussion in Niccolò Machiavelli's famous treatise The Prince

In the end, our alchemist's territories were confiscated by yet another pope, Alexander I, and her story does not end well. She was captured, raped and imprisoned. Alexander justified her incarceration, in the Vatican's Sant'Angelo Castle, by claiming she tried to poison him. She survived the ordeal, but after release entered the convent of the Murate nuns in Florence, and died, in 1509, at the age of forty-seven. She was buried at the convent, in the same city where her future great-great-grandson, Don Antonio, along with Antonio Neri, would perform their own alchemical experiments and help usher in the age of  modern science.

[1]https://sites.eca.ed.ac.uk/renaissancecosmetics/cosmetics-recipes/caterina-sforzas-experimenti/ also see  http://edinburgh.academia.edu/JacquelineSpicer.
[2] Another possibility for the model of Venus was Simonetta Vespucci.
*This post first appeared here on 27 January 2014.