Dear Readers,

As you may have seen elsewhere, in mid February my wife and I suffered the loss of our home in a fire, in the hills of central Massachusetts. The good news is that we got out safely and had no animals in our care at the time. The fire crews were able to contain the fire from spreading, in what turned into a 3-alarm, 5-hour-long ordeal in subzero temperatures; they did amazing work, and no one was injured. The bad news is that all of my physical historical materials and research of 30 years have gone up in smoke. As a result I have decided to suspend this blog for the time being. It will remain online as a resource for those interested in the history of glass and glassmaking in the seventeenth century and beyond. I do intend to resume writing when I can, but for now my time and energy are required in getting us back on our feet.

Friends are providing temporary shelter for us nearby and our intention is to rebuild as soon as possible. To those who have reached out with a steady hand, to those who have opened their wallets, and offered advice in our time of need, we thank you from the bottom of our hearts. In what are already difficult times for all of us, you have made a huge difference in our lives.

Paul Engle
6 March, 2021

Wednesday, November 30, 2016

The Knights

Fra Antonio Martelli, Knight of the Order of Malta,
Attrib. Caravaggio, c. 1608.
"Of me, Priest Antonio Neri, Florentine 1598." So starts the inscription on the first of 61 ink and watercolor illustrations in a manuscript titled "Tesoro del Mondo" [Treasure of the World]. It is the earliest manuscript known to exist by the respected glassmaker and alchemist, started when he was just twenty-two years old. Given the Church's rules and the typical length of training for ordination, twenty-two is about the youngest age possible for a priest. In fact, it is likely that the responsibility was granted to him mere months or weeks before the ambitious manuscript was begun, which he dedicates to the exposition of "all of alchemy." 

This scenario raises the intriguing question of which religious order would have taken on the sponsorship of educating a future priest as an alchemist; a mystery that remains unanswered to this day. Recently, we looked at two promising possibilities; the Canons Regular, and the Dominicans. Today we investigate a less conventional possibility: the Knights of Malta. The knights were ancient aristocratic military order that originated during the crusades and in Neri's time ran the papal navy. 

The Knights of Malta headed two churches in Florence and Neri can be connected to both. With the first, our priest has an indirect association. San Giovannino dei Cavalieri, (formerly called San Giovanni Decollato) is located a few steps from the Casino di San Marco, where Neri made glass at the beginning of the seventeenth century. His sponsor and owner of the Casino was Medici prince Don Antonio, whose daughter Maddalena later served as a nun at the associated convent. [1] The second church, San Jacopo in Campo Corbolini, is directly connected to Neri in a story recorded shortly after his lifetime. [2]

The following passage contains much that is contradicted by the facts, yet infused enough with the truth to make us wonder. Historian, courtier, genealogist and Florentine senator Monsignor Girolamo da Sommaia [3] recounted that:
M. Antonio who had died in Florence five or six years earlier and was from San Jacopo in Campo Corbolino,[4] said that he had the [philosophers] "stone," which he found in a pen-written book of secrets and took the paper and showed it to Casa (Agnolo Talducci della Casa, from the reign of Ferdinando I) who said what he was holding was sophistry, but that the cost was very little to try, so he tried it, and saying he succeeded, he told Casa and a goldsmith on the Ponte Vecchio, who did the first assay and later in his presence threw a bag of that powder into the Arno.[5]
A number of notebooks chronicle Neri's long working association with Della Casa at Don Antonio de' Medici's laboratory. These and other documents cast considerable doubt on the veracity of Sommia's story. Nevertheless, individual details do ring true. Of particular interest is the name of the church, San Jacopo in Campo Corbolini. It still stands today, a block west of the mercato centrale in Florence. The Knights Templar occupied it since 1256 and when that order died out, the Knights of Malta took it over. Neri's affiliation may have been through his work for Don Antonio, who belonged to the order. Another possibility is that Neri was attached to the knights through his father's connections at court. The order maintained a great deal of independence, reporting directly to the pope and curia. Their main presence was on Malta, Neri was not a knight but he could have occupied a place in their clergy.

The knights followed the rule of Augustine and enjoyed a close relationship with the Augustinians. The order traces its roots to the crusades [6] and has various associations with alchemy, notably George Ripley. [7] The fifteenth century English physician and alchemist was ordained into the Canons Regular of Saint Augustine, but he later joined the Carmelites. He is purported to have used gold produced through alchemy to help finance the Knights of Malta in the war with the Ottoman Empire. [8] Folklore maintains that Ripley learned transmutation as part of his Italian schooling in alchemy.

[1] Luti 2006, pp. 171, 172.
[2] See Targioni-Tozzetti 189.
[3] Girolamo da Sommaia (1573–1635). He served as provost of the university (studio) at Pisa and prior of the convent church of the Knights of Saint-Etienne in the years 1614–1636. He was also a friend and supporter of Galileo.
[4] Today, this church is called S. Jacopo in Campo Corbolini. It was founded in 1206.
[5] Related in Targioni-Tozzetti 189, thanks to Maria Grazzini for pointing me to this passage.
[6] Known variously through history as the Knights Hospitaller, the Knights of Rhodes, the Knights of St. John of Jerulsalem and the Knights of Malta.
[7] Sir George Ripley (ca. 1415–1490), Bridlington, York. Cf. Rampling 2008; McCallum 1996.
[8] Fuller 1840.

Monday, November 28, 2016

Veins of the Earth

Antonio Neri, "The Mineral Gold"
Neri 1598-2000 (Ferguson 67), f. 5r.
Over a decade before Antonio Neri wrote L’Arte Vetraria, the book on glassmaking for which he would become famous, he wrote an illustrated manuscript on the subject of alchemy. Begun around 1598 and completed in 1600, this is Neri's earliest known work, written very shortly after he was ordained as a Catholic priest in the city of his birth, Florence, Italy. 

The illustrations are divided between technical depictions of chemical apparatus and allegorical images meant to show philosophical relationships within the natural world. Two of Neri's pictures from this latter group, respectively, show veins of gold and silver growing in the earth. The veins are depicted exactly like the arteries of an animal. In both pictures, they radiate out around fiery holes in the ground, what one might presume to be volcanos. Overhead the sun shines down on the gold and the moon over the silver; the alchemical symbols for these metals. Further up in the sky, Neri shows the constellations associated with each metal; Leo the lion for gold and Cancer the crab for silver (his rendition looking more like a lobster).

It was no flight of fancy that mined metal and ore deposits were depicted as literal, growing veins. It was widely thought these were living structures, which carried the earth’s nutrients. In one of Neri's final works, his 1613 manuscript Discorso, he explains the ancient theory that gold could occur as immature seed material, left over from the primordial creation. If properly nourished, this seed would mature and grow into the precious metal, and with the appropriate knowledge this natural process could be restarted, or accelerated and the gold could be brought to perfection by artificial means. 

Antonio Neri, "The Mineral Silver"
Neri 1598-2000 (Ferguson 67), f. 6r.
The idea that mined mineral deposits could regenerate naturally, if left to rest, is an ancient concept, one that persisted long past Neri’s era. In 1814, writing about tin mining in "On the Veins of Cornwall," William Phillips complained to the Geological Society of London, that armed with some current scientific knowledge, "nor would many miners […] believe, even to this day, in the regeneration of metals." but alas, they did believe it fervently. Phillips quoted from an 1811 survey by Tonkin, in Carew's survey of Cornwall: "Whether tin doth grow again, and fill up places which have been formerly wrought away, or whether it only seperateth itself from the consumed offal, hath been much controverted, and is not to this day decided." And  "whether—dead lodes—that have not one grain of tin in them—may not hereafter be impregnated,  matured,  and prove a future supply to the country, when the present lodes are exhausted, I think well deserves our highest consideration."  It is an interesting notion that well into the nineteenth century, at least some miners were convinced that their line of work brought them into intimate contact with a living organism, the earth.

At base, this conclusion is not superstition nor wild speculation, but rather considered judgments of thoughtful men making careful observations. Mines were often attended by acidic or other caustic liquids, either produced naturally or by washing operations, which leached out and dissolved various solubles. These liquids could sometimes dissolve metal out of ore and redeposit it elsewhere. Abandoned mines, it was noticed, could exhibit new crystal growth after a period of years or centuries. Today, the redeposition of minerals is a well accepted phenomenon, however, where it does occur it often takes place not on a human time scale, but on a geological one, over millions of years.

*This post first appeared here in a slightly different form on 2 December 2013.

Friday, November 25, 2016

Bibliomaniac

Broadway Tower, Worcestershire. 
The home of Phillipps' Middle Hill Press
In 1612, Antonio Neri published his famous book on glassmaking, L'Arte Vetraria. [1] The venture was bankrolled by Medici prince Don Antonio for whom Neri had worked as an alchemist and glassmaker in 1601 and possibly a couple of years earlier. The printer was Giunti, the venerated Florentine family of typographers who set up their first press in Venice a century and a half earlier. In Neri's era, they operated as the de facto press for the grand dukes in Florence and they are still in business today.

Neri's book was noticed almost immediately; in a 1614 letter addressed to Galileo, Roman Prince Federico Cesi practically begged his astronomer friend to send a copy. [2] Cesi was the founder of the "Accademia dei Lincei" [Society of Lynxes] a group of naturalists who formed an early version of what would later be called 'scientific societies.' The book was tailor made for such groups who were interested in performing their own experiments, however, sales did not exactly catch fire among the public. 

A few decades later, another scientific society was formed in London, with a charter signed by no less than King Charles II. The Royal Society really gave Neri's book a major boost when in 1662; founding member Robert Boyle commissioned Christopher Merrett to translate the work into English. [3] A year earlier, a second edition had been printed in Florence and a year later, another Italian edition appeared in Venice. [4]

From there, the book took off, sprouting multiple new translations in the Netherlands, Germany, France and Spain. There are many interesting stories of how the book spread across Europe; one of the most fascinating deals not with the book itself but with a publisher. Without any doubt, Sir Thomas Phillipps was the most colorful of any of Neri's printers. In 1826, Phillipps' press issued a reprint of Merrett's original English translation, which was by then over a century and a half old. [5]

By the 19th century, L'Arte Vetraria, or "The Art of Glass" as it was dubbed in English, had passed its prime as the bible of glassmakers. As one would expect, methods and technology had matured considerably over the intervening two centuries. Nevertheless, Phillipps recognized its importance. He was also a bit eccentric. As a child, by his sixth birthday, he already owned over a hundred books; his grand ambition was to own one copy of every book ever printed, a quest he carried into adulthood. He was born in Manchester, the product of a clandestine relationship between a textile baron and a woman other than the one to whom his father was married. Nevertheless, he appears to have been well cared for and inherited what Wikipedia reports was a "substantial estate." [6] A fortune that he promptly started to whittle away, spending lavishly on books and manuscripts. He attended University College Oxford and within a few years, he was made a fellow of the above-mentioned Royal Society. 

Depending on where you stand, Phillipps was a classic example of British eccentricity, a brilliant and dedicated preservationist or a completely obsessed crazy-man. Possibly all three. By the end of his life, he had amassed an estimated sixty thousand manuscripts and forty thousand books. At the time it was the largest such private collection in the world. He housed his treasure in a castle that he had built for the purpose, Broadway Tower, in Worcestershire (see photo above). It is said that he would walk into various bookstores and buy the entire stock; his agents around Europe provided a steady stream of new material. Apparently, he himself possessed a sense of humor about his odd obsession, coining the term "vello-maniac" (referring to the vellum bindings common to many books of that period).

The story does have a darker side, albeit with a silver lining. In 1842, Phillipps started collaborating in research with James Halliwell, then an undergraduate at Cambridge studying Shakespeare. Halliwell became romantically involved with Phillipps eldest daughter Harriett, but Phillipps refused consent for them to marry (which they did anyway). Meanwhile, Phillipps had run through the family fortune and started to borrow heavily. He developed paranoia against Halliwell and vowed that he would never gain control of the collection. He entered negotiations to donate the books and manuscripts to the British Library, but his conditions were unpalatable and a deal was never reached. He wanted to stipulate that the order of books should never be reshuffled and that no Roman Catholic, especially his son-in-law, ever be permitted to touch or view the collection. He became so fearful  about Halliwell that he hired 250 men to move the collection, which took two years, at which point the abandoned castle started to fall into ruins. 

In the end, Phillipps died at the age of 79 in 1872. After a court decision, Harriett did inherit her father's collection and Halliwell did gain control. The silver lining is that the two undertook to carefully disperse the collection to some of the most prestigious libraries in Europe. This project took multiple generations to finish. In fact, the final parcel of books from the Phillipps collection sold at auction in 2006, at Christie's.

[1] Neri 1612.
[2] Cesi 1614a, 1614b.
[3] Neri 1662.
[4] Neri 1661, Neri 1663.
[5] Neri 1826.
[6] "Thomas Phillipps" Wikipedia, http://en.wikipedia.org/wiki/Thomas_Phillipps 
* This post first appeared here on 5 Oct 2014.

Wednesday, November 23, 2016

Yellow Glass

Yellow Neon Chandelier, 1995
Dale Chihuly.
(Columbus, Indiana Visitors Center). 
"Very few people know how to make colors like golden yellow and solid red well. These are difficult and troublesome in the art of glassmaking, since in making them you must stick precisely to the doses, the timing, the details and the materials as prescribed. The smallest error will cause everything to be ruined, and the colors to be irreparably spoiled. Therefore, you must be on guard not to make mistakes. [1]
So says Antonio Neri in his groundbreaking 1612 book of glass recipes, L’Arte Vetraria. Elsewhere he warns in several places not to add “tartar” to any glass destined for yellow pigmentation. Tartar was a common additive to boost the ‘sparkle’ of a glass because it contained a high level of potassium carbonates. These converted to potassium oxide in the melt, which has a higher refractive index than the usual glass flux, sodium oxide. 

However, the reason for the mismatch is not clear, since Neri also says of his “fern glass,” which is entirely potassium based:
…This frit can be given a wonderful golden yellow color provided there is no tartar salt within, as described in the caution, because then golden yellow will not emerge. This crystal is given to a golden yellow that is far more beautiful and pleasant than can be achieved in cristallo made with Levantine polverino salt and with this crystal unlike the other, every kind of job can be done. [2]
“Polverino” was a sodium based plant product used in many of Neri’s glass recipes, which he says was derived from the Kali plant grown in the Levant. The plot thickens when, for yellow, he recommends substituting ‘rocchetta’ another soda based Kali derivative. 

His primary recipe for golden yellow is #46, in which he reveals two ingredients responsible for the color: “For every 100 pounds of [glass], add 1 pound of tartar from the dregs of red wine. Use large pieces well vitrified naturally in bottles of wine, because the powder is no good. Crush these raw dregs well, and pass them through a fine sieve. For every 1 pound of these dregs, add 1 pound of prepared Piedmont manganese…” [3] To this he adds the advice that “the powder is always given in parts and given [to the frit], not to the fused glass, because then it will not tint.”

He also offers advice to add more or less pigment depending on the intended use of the glass: more for thin items, less for heavier ones. “For larger [thick] spit beads, it is said that at Murano they reduce the dose of [wine] dregs and manganese by nearly half.”

For Neri’s lead glass, he uses a different combination, this time pairing copper sulfate with iron oxide: “Take 16 pounds of cristallo frit and 16 pounds of lead calx. Mix them well and pass them through a sieve. To this material, add 6 ounces of thrice cooked copper, made with flakes of the kettle-smiths [chapter 28], and 2 pennyweight of iron crocus made with vinegar [chapter 17].” He goes on to advise, “If it leans toward greenishness, add a little iron crocus, which will remove the greenishness and will bring out a yellow color of the most beautiful gold.

Yellow is one of several colors that iron oxide can form in glass, and is used frequently in low-fire pottery glazes. In that realm, it has a reputation as a difficult, unstable color, as Neri alludes to in his warnings. But in modern, higher temperature borosilicate glass, iron oxide is relied on for a nice yellow. In modern soda-lime glass, cadmium, titanium or the exotic praseodymium are more likely choices. They produced bright reliable color that is stable at the higher temperatures of modern operations. In lead glass, selenium is the modern favorite for yellow.

[1] Neri 1612, ch. 45.
[2] ibid, ch 5.
[3] ibid, ch 46.

Monday, November 21, 2016

Lead Crystal

Roemer type drinking glass c. 1677,
George Ravenscroft.
The entire fourth part of Antonio Neri's book L'Arte Vetraria is devoted to the preparation of lead glass, a forerunner of what is now commonly known as lead crystal. This section is unique in the book in that it contains the only instance of the author giving direct advice to glass artists themselves:
"To work lead glass into various drinking glasses or other vessels, or even to draw cane for beadmaking, it is necessary to raise the punty [out of the melt], and to make a gather of glass by turning. Take it out, let it cool somewhat and then work it on a well-cleaned marble [marver]. The marble should be somewhat cool, and well bathed with water before use."
He goes on to describe what might be termed a kind of dance with the glass. As with a human partner, gentle patience is required in learning the boundaries of what can and cannot be done. Ultimately, an artist must come to understand the material's behavior and personality in order to result in a great partnership. For the artist who makes unrealistic demands, glass can be a heartbreaker.  
"This sort of glass, lead glass, is so runny that were it not cooled, and taken up by turning [the punty] to wind a gather, it would be impossible to work. It is so runny that it would not even hold onto the punty, because it is as loose as soup. This arises out of [the fact that] the lead calx causes it to become very fluid."
"Namely, gather the glass little by little, allow it to cool, and work it over marble frequently bathed in water. Furthermore, make sure to keep the pot of glass rather calm, and in a place in the furnace where it will not see too much heat, otherwise it will not be possible to work this glass at all."
The formulation of lead crystal as we know it is a relatively recent development. This is a composition of crushed silica (sand or quartz), potash (potassium carbonates) and lead oxide substituting for calcium to stabilize the composition. It is also true that lead has been added to glass since its invention a few thousand years ago. It is not clear that this addition was always intentional, but a Babylonian tablet of 1700 BCE gives a recipe for pottery glaze that explicitly contains lead. At some point, a discovery showed that small amounts of lead and pigment smeared on glass and fired made stained glass paintings possible. The earliest known examples of colored stained glass windows date to 800-820 (San Vicenzo Abbey excavation in Volturno, Italy.)  In medieval Europe, leading up to Antonio Neri's time, lead glass was used in mosaic tesserae and in artificial gems.

Finally, it is worth noting that Neri's childhood church in Florence, Cestello (now called Santa Maria Maddalena dei Pazzi), was then run by Cistercian monks. It was the Cistercian luminary St. Bernard of Clairvaux who, in the twelfth century, built the first church with large windows, urging, "The soul shall seek the light by following the light."

This post first appeared here 15 November 2013.

Friday, November 18, 2016

Women in Alchemy

Antonio Neri, 1598-1600,
MS Ferguson 67, f. 25r.
It is certain that women have participated in the practice of alchemy since its beginnings, but hard documentation is scant. Maria Prophetissima, also known as Mary the Jewess, is perhaps the best known female alchemist. None of her writings have survived, but she is thought to have lived around the third century. Legend tells that the "bain-marie" (double boiler) is named after her.

In the seventeenth century, One of Antonio Neri’s manuscripts, entitled Tesoro del Mondo (Treasure of the World) depicts three women running chemical equipment. It is possible that these were nuns, trained in the same Church sponsored educational system that produced Neri. Convents were often expected to be self-sufficient and many ran their own pharmacies. Neri had sisters as well as brothers and at least one sister entered a convent located on the north side of Florence, near the laboratory where Antonio practiced alchemy and made glass. The fact that specific names have not been associated with Neri’s three female co-workers should not deter us from celebrating their contribution to the birth of early modern science.

Within a year of his ordination in the Catholic Church, Antonio Neri began an ambitious treatise, illustrated in his own hand, devoted to "all of alchemy." Six of the illustrations in this manuscript, completed in 1600, show women tending equipment. It is not remarkable that some alchemists of the 16th century were women, what is remarkable is to find them in the historical record. Direct depiction of female participation in alchemy is otherwise extremely rare. 



Two pictures in the Neri manuscript show female alchemists at
Antonio Neri, 1598-1600, 
MS Ferguson 67, f. 35r.
work. In both cases, the technician stands behind a dedicated piece of apparatus, facing forward, giving the impression of propriety in an arranged portrait. In other words, Neri is drawing his co-workers at their stations, practicing their art. The first drawing depicts a furnace and vessels used to make liquid mercury from its ore. The other shows a different type of furnace with a 'tower,' used as an efficient way to cook ceruse (white lead oxide). These images are part of a larger set of two dozen similar drawings that each illustrate the equipment used to prepare a specific product, many include a furnace and glassware. Nine of these show a single individual, (or in one case two men) tending the equipment. Because the manuscript is a recipe book, it contains almost no personal information. However, the context of these illustrations indicated that like their male counterparts, the individuals depicted all have specific responsibilities and specializations within the workplace.


Three other illustrations in the manuscript are notable for their engagement of women. These pictures show details of kitchen and nursing work; what might be termed more traditional female roles in the sixteenth century. Two of these illustrations are devoted to the respective arts of preparing plants and animals. They show women working alongside men performing various tasks. A third illustration shows medicinal fogging tents tended by a woman. Inside one tent, a male patient sits naked on a bench, exposed and breathing fumes pumped in by a large vessel perched over a fire. Similar arrangements are known to have been used to treat skin lesions caused by leprosy and syphilis.
Antonio Neri, 1598-1600, 
MS Ferguson 67, f. 37r.
The circumstances in these images present other possibilities to Antonio Neri's work environment. One is that the scenes take place at the Neri household on Borgo Pinti in Florence. Antonio's father was the personal physician to Ferdinando de' Medici, the grand duke of Tuscany. He was also the head of the college of physicians, and presumably ran a thriving private practice. The women may be Neri's siblings or other family members. 

Another possibility is that we may be looking at operations inside the Casino di San Marco soon after prince Don Antonio de' Medici's occupation of the facility. This palace laboratory had a reputation for medical cures that extended throughout Europe. Don Antonio spent extravagant sums to learn alchemical and medicinal secrets. The glass furnace here, which had employed masters from Venice is where Neri began formulating glass. The presence of women among his colleagues indicates a social setting with a camaraderie not displayed in other alchemical works of the period. 

* This post first appeared here on 17 March 2013 in a slightly different form.

Wednesday, November 16, 2016

Sara Vincx

Still life with façon de Venise wineglass,
Alexander Adriaenssen (1587-1661)
Antwerp.
In the 1590s, after the death of her husband, Sara Vincx ran a successful glassmaking business in the city of Antwerp. In the midst of a major war, she presided over a furnace where craftsmen from Murano, Italy made fine cristallo glassware for the elite families in Flanders. Vinx is the first documented female owner of a glass furnace anywhere.

The Dutch Eighty Years' War for independence from Spain was heating up in Flanders; towns were being pillaged and burned to the ground throughout the Low Countries. Even so, Vincx ably managed a crew of expert glass artists and brought her company's wares to market. When competitors tried to duplicate her products, she successfully defended her shop in court. Later, she remarried to Filippo Gridolfi, one of her foremen at the furnace. The two went on to open a show-room on the Meir, the most prestigious sales district of the city. They also welcomed glassmaker Antonio Neri to work at their facility. Neri was living in the city on an extended seven year visit to his friend and fellow alchemical experimenter Emmanuel Ximenes. 

The seven years that Antonio Neri spent in Antwerp were arguably the most formative for his knowledge of glassmaking. While his first exposure to the art was in Italy, a large portion of the skills and recipes exhibited in his recipe book, L'Arte Vetraria, trace to his activities in the Low Countries. Neri writes "This will make a beautiful aquamarine so nice and marvelous, that you will be astonished, as I have done many times in Flanders in the city of Antwerp to the marvel of all those that saw it." On tinting rock crystal: "In Antwerp, I made quite a bit of this, some ranged in tint from an opal color that looked very beautiful, to a girasol, similarly nice." On equipment: "In Antwerp, I built a furnace that held twenty glass-pots of various colors and when fired for twenty-four hours everything fused and purified." He also speaks of chalcedony glass, paste gems  and ultramarine paint all crafted in Antwerp.

Neri was apparently on good terms with Vincx and Gridolfi, perhaps he was introduced through Ximenes, one of the wealthiest men in the city. In his book Neri describes Gridolfi as "a most courteous gentleman." Vincx and Gridolfi possessed exclusive rights in the region to produce cristallo glass in the Venetian style (façon de Venice) a type of glass that Neri was already quite familiar with from his time making glass in Florence and in Pisa. The license, or patent as it was called, passed down from previous owners, was quite a valuable part of the operation. Employed in their shop was a steady stream of craftsmen from Murano. They made the finest glassware for the upper classes of Antwerp and surrounding areas. Because these craftsmen were bringing the secret techniques with them, they worked outside of the guild system, which would have otherwise required them to share their techniques with other artisans. Through special arrangements with the local authorities, the Venetians were exempt from joining. 


Sara Vincx (or Vincks) was the widow of the former owner, Ambrogio de Mongarda. Gridolfi had previously worked in the shop under Mongarda, who had been in the business for twenty years. Vincx was pressed into service by unhappy circumstances. In 1594, Ambrogio returned alone to Venice to recuperate from gout, but by the following year he was dead, leaving Sara to both run the glass shop and care for at least eight young children. Sara Vincx carries a distinction as the first documented female owner of a glass furnace anywhere. She took an active role in the business as attested by lawsuits she filed, and won, against rival shops that violated her patent. Records show she also expanded the furnace and hired two new artisans to increase production.

Despite the war and the blockade of the Scheldt River, which shut down trade by sea for a number of years in Antwerp, the glass furnace there thrived and reached its zenith under Vincx and Gridolfi. Soon after their marriage, seventeen employees were counted working at the shop. They established their own retail presence on the Meir, selling high-end cristallo within steps of the Ximenes palace. Their glass operation enjoyed top-rung status, and no doubt, Antonio Neri's involvement must have bolstered the reputation of the firm even further.

*This post first appeared here in a shorter form on 4 October 2013.

Monday, November 14, 2016

The Beguines

A Béguine of Antwerp,
from Pierre Hélyot,
L'Histoire des ordres monastiques… 1719 (v.8)
Five years into his stay in Antwerp, on 21 February 1608, Antonio Neri posted a letter to a friend in Florence. The letter was addressed to the house of Zanobi Bartolini—likely the son of Neri’s late former landlord Alamano, also the nephew of Emmanuel Ximenes, Neri’s host in Antwerp. The letter provides strong evidence that however much time Neri devoted to making glass, he also devoted considerable attention to his interest in medicine. 

In this letter, the priest describes his success with medicinal cures. He also references experiments he carried out in Brussels and at the Hospital of Malines, in Mechelen. In particular, he praised Paracelsus’ recipe for ‘theriac of mummy,’ and its superiority to Galen’s ‘theriac magna’. Theriac was an ancient medicinal remedy, often taking the form of a thick honey based syrup. It often contained numerous herbal ingredients. It was thought to be a cure for any poison and used as a way to stave off the plague. Mummy or mumia was a compound composed of just what one might think: the ground up flesh of ancient Egyptian bodies. 

The Hospital of Malines was an ancient one, started in the thirteenth century by a society of lay Catholic women called Béguines. In their 1907 book A History of Nursing, Dock and Nutting note:
Through the whole time of the active career of the Béguines, nursing remained an important branch of their work. One of their most beautiful settlements was at Malines, where there were over 1500 Sisters, not including their dependents. This would appear to have been a nursing center of importance, for Helyot says that the nursing in many hospitals was provided for by orders arising from the Béguines of Malines. […] The building were surrounded with extensive gardens and trees, and had an ample water supply. ‘The sick were nursed there’ he [Helyot] wrote ‘with all the skill, refinement and sweetness that might be expected from the appearance of the place. [1]
The Béguines were not nuns. They did live in communal housing, and did devote themselves to a pious lifestyle, but without formal cloister, without renouncing their possessions, and taking only a temporary vow of chastity, able to leave at any time, for instance to get married. They formed corporations throughout the Low Lands and into France and Germany that were self sustaining and largely independent of local control. These were huge organizations of women, working for themselves, under their own roofs and by their own rules. They produced crafts and textiles, they schooled nurses and they ran hospitals. Because they existed on the fringes of Church control, they were downplayed or even resented within the hierarchy. One result is that their achievements have largely been forgotten by history. When Mathias Hovius, the Archbishop of Mechelen, toured the facilities in 1601 he took the petty action of requiring Béguines who chose to keep lap-dogs to pay a fine to the Church. In 1630, Bishop Malderus of Antwerp defended the women in an extraordinary letter. He wrote,
The Order of the Béguines is truly not a religious order, but a pious society, and compared with the former complete consecration is as a preparatory school in which the piously inclined women of Belgium live after a pattern highly characteristic of the temper and mind and the character of the people. For this people is jealous of its liberty and will be led rather than driven. Although it is beyond a doubt more meritorious to devote one’s self to the service of heaven by vows of perpetual chastity, obedience, and poverty, and though there are many pious women in Belgium who are so disposed, yet most of them shrink from this irrevocable vow. They prefer to remain inviolably chaste rather than to promise to be so; they are willing to obey, but without formally binding themselves to obedience; to rather use their poverty in reasonable outlays for the poor than to give it at once up for good to all; rather voluntarily renounce daily the world than immure themselves once and forever.[2]
At the beginning of the seventeenth century, the hospital was used to treat wounded Spanish and Italian soldiers fighting in the war against the Dutch. By 1607, just before Antonio Neri wrote his letter, the staff at the hospital numbered fifty, “including seven doctors, eight surgeons, and three surgeon’s mates.”[3]

As the son of a grand duke’s personal physician and grandson of a surgeon, there can be little doubt that Neri had ample familiarity with medical procedure. It seems likely, given the circumstances, that in Mechelen he was lending his expertise to ease the ravages of war, helping to heal wounded soldiers.

[1] Lavinia L. Dock, Mary Adelaide Nutting, A History of Nursing (Putnam, 1907) v. 1, p. 268.
[2] Ibid, p. 269.[3] Geoffrey Parker, The Army of Flanders and the Spanish Road, 1567-1659 (Cambridge Univ. Press, 2004), p.141
[3] Ibid, Dock, Nutting 1907.
* This post first appeared here on 26 Mar 2014.

Friday, November 11, 2016

Caterina Sforza

Caterina Sforza, by Lorenzo di Credi
(now in the Museum of Forlì.)
Antonio Neri is remembered mostly for his book on glassmaking, L'Arte Vetraria. However, 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. 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 (Passolini). 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 she was captured, raped and imprisoned on the orders of Pope Alexander VI, who 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.

Wednesday, November 9, 2016

The Paracelsans

Image of Paracelsus.
In the late sixteenth century, the writings of an obscure physician started to become very popular around Europe. Born in 1493 with the name of Theophrastus von Hohenheim, "Paracelsus"[1] was the son of a German physician living in Switzerland. He took a degree in medicine from the university at Ferrara and proceeded to wander through Germany, France, Spain, Hungary, the Netherlands, Denmark, Sweden, Poland and Russia. He died in 1541, nearly half a century before the various pamphlets he wrote started to be noticed and reprinted. In his lifetime he was hounded out of one European city after another for defying traditionally accepted medical practices and insisting on doing things his own way. He was known for somewhat difficult personality, and the somewhat gloomy but steadfast conviction that the world would shortly come to an end. Today he is celebrated for basing his diagnoses on a careful observation of nature, and of his patients actual symptoms, a sometimes radical departure from the norm for his time. 

By the end of the sixteenth century, his writings were being circulated among the intelligentsia of the Florentine royal court in Italy. His opinions extended not only to medicine and anatomy, but also to alchemy, botany, pharmacology, astrology, and what would later be called psychology. Paracelsus' philosophy was a powerful influence on the education of Antonio Neri in the discipline of alchemy.  Neri's father was the royal physician to Florentine Grand Duke Ferdinando de' Medici, and almost certainly did not subscribe to Paracelsan ideas, but Antonio seems to have taken a different path. His benefactor, Prince Don Antonio de' Medici was a confirmed Paracelsan.

By the time Neri's book on glassmaking appeared in 1612, the priest counted himself a devoted Paracelsan spagyricist and he as much as says so. In his introduction, he holds out the future possibility of publishing “the experience of my endeavors over many years, working in diverse parts of the world […in] the chemical and spagyric arts.” [2] Paracelsus had pioneered two new disciplines that he named "iatrochemistry" and "spagyrics." Iatrochemistry dealt with the use of minerals and chemicals in medicine; spagyrics made use of plants and their extracts. Here we get a hint that Neri's true passions lie beyond the formulation of glass. Speaking about the potential of chemistry in medicines, also in the introduction, he writes, "These are matters of nature to which I believe there is no higher calling in the service of humanity." The same techniques and terminology used to produce medical remedies shows up in Neri's glass formulations. Twice, he refers to ingredients as "medicine," [3] which he adds to the glass melt in "doses." He also uses the somewhat specialized apothecary's term 'ana', [4]  which means "in equal parts." 

Paracelsus coined the word "spagyric" in his book Liber Paragranum, [5] where he argues medicine should be based on the physical laws of nature alone. The word derives from two Greek terms: spao meaning to separate and ageiro meaning to combine. The underlying philosophy recurs throughout the history of alchemy. To enhance the special properties of a plant, break it down, to its separate constituents, then purify each and recombine them for a more potent product. Herein lay the bones of Neri’s empirical methodology with glass; one built on the processes of reduction, purification and recombination. These methods appear throughout his technical recipes. Neri utilizes the method with both plant and mineral ingredients, in the preparation of basic materials and pigments and throughout his medicinal work. You could say that these very techniques and the resultant near mania he developed for purification are responsible for the high reputation of his glass formulas. His colors were bright and clear beyond what was produced by typical preparation by artisans of his time. 

In letters from his friend Emmanuel Ximenes, around 1600 the two men discuss Paracelsus in their correspondence, but do so carefully since it is still a rather controversial topic. [6] By 1608, Neri seems a bit more relaxed, writing to a friend that he had cured diseases using the "grandissima meraviglia" (wonderfully grand) methods of Paracelsus. [7]

Mere months before his own death in 1614, Neri wrote a small tract titled Discorso. The full title translates to 'Discourse on Chemistry, what it is, and its Operations'. [8] In it, he "manifests right from the outset his adherence to the Paracelsan doctrine, which is not restricted to inorganic chemical operations involving the transmutation of metals, but has broader applicability to the field of medicine." [9] Neri begins:
The operations belonging to chemistry do not only, as some estimate, involve the transmutation of metals. It is a much more universal art, which in some ways also embraces medicine (or at least it comes very close in assisting) and it can be defined. It is an art, which resolves and reduces all ‘mixed bodies’ [corpi misti] into their primary elements, it searches out their nature and separates the pure from the impure and it makes use of the pure to perfect these bodies and even to transform one body into another. [10]
History has mostly remembered Neri as a glassmaker, but his own philosophy was a bit different. He considered himself first and foremost an alchemist and his art—the art of chemistry—was a discipline that embraced metallurgy, glassmaking and medicine. 

[1] often referred to as Philippus Aureolus Theophrastus Bombastus von Hohenheim, this concatination was not used to refer to himself. for a fascinating discussion see Thony Cristie's post here: https://thonyc.wordpress.com/2012/05/01/whats-in-a-name-2/
[2] Neri 1612, p. vii.
[3] Neri 1612, pp. 40, 104, medicina; p. 9, dose and throughout. 
[4] Neri 1612, p. 98 ana
[5]Opus Paragranum, written in 1529/30 not published until 1565. Cf. Paracelsus 1565.
[6] Neri 1980, pp. xlii–xliii, lix. In his letters, Ximenes is careful about references to Paracelsus. 
[7] Neri 1608; Zecchin 1987–89, p. 157. “… che già stava in casa il s.r. Zanobi Bartolini, che mostra gl’ effetti di mali da lui guariti secondo gli ordini Paracelsici di grandissima meraviglia…” [that previously when in the house s.r. Zanobi Bartolini showed the effects on sicknesses that he healed using the instructions of the great and marvelous Paracelsus ....].
[8] Discorso sopra la Chimica, che cosa sia, e sue Operazioni, Neri 1613.
[9] Grazzini 1983, p. 221. 
[10] For the original Italian, see Grazzini 2012.

Monday, November 7, 2016

Neri's other Rubino Glass

Rhodochrosite, from the Sweet Home Mine, Colorado.
Antonio Neri is widely recognized for publishing a recipe for the coveted and difficult gold ruby glass. "Rubino", as it is sometimes called, achieves a deep ruby red color utilizing only powdered metallic gold as a colorant. Perhaps because of the notoriety of that prescription, Neri’s other transparent red glass is hardly known. His recipe #120 describes a deep red pigment based on manganese. Today manganese takes its place on the periodic table as an elemental metal, but in the early seventeenth century it had not been isolated from its mineral ore. What Neri calls manganese was actually its oxide, which occurs as a black powdery material. Its effects in glass have been known since the early Egyptian dynasties and before that, as a pottery glaze. By itself the oxide produces a tint often likened to violet or amethyst. In small quantities, it is used to neutralize the slight green tint introduced by iron impurities in clear glass. 

To make his ruby red pigment, Neri starts with high quality manganese oxide from Piedmont and processes it through several alchemical operations. I will not be delving into the chemistry in detail here, but suffice it to say that he comes astoundingly close to synthesizing a highly unstable explosive, the likes of which was not "discovered" for another two centuries. It is a striking illustration of how technical ability can be in place long before theory catches up, in this case thankfully so. 

The pigment he did succeed in making is for now a mystery. Manganese carbonate, which can form ruby red crystals might fit the bill, except that it decomposes at the temperatures of molten glass. It occurs in nature as the mineral rhodochrosite as seen above. [1] Below is Neri's recipe for "Transparent Red in Glass" from his 1612 book L’Arte Vetraria. Most of the terminology is straightforward, with the exception of a few terms. 'Porphyry' is a hard granite used for grinding stones. 'Reverberation' is indirect radiation in a furnace, where the heat is reflected from the walls. 'Sublimation' is when certain materials vaporize directly from a solid form and recondense without passing through a liquid phase.
Grind manganese impalpably, then mix it with an equal amount of refined saltpeter and put it into a clay pan set to the fire, reverberating and calcining it for 24 hours. Take it then and wash its saltiness away with warm common water. Once separated from the salt, let it dry. It will be a ruby-red color. With this, mix an equal weight of sal ammoniac and grind them together over porphyry stone with distilled vinegar, which they will soak up. Leave this alone to dry and then put it in a retort with a wide body and a long neck. Heat it in sand for 12 hours to sublimate. 
Then break up the glass. Take all the deposits in the neck and body of the retort and mix it with the residual remains in the bottom. Weigh it and combine it all with as much sal ammoniac as was lost in the first sublimation. Grind everything together over the porphyry stone, with distilled vinegar for it to soak up. Then put it in a retort to sublimate as above. Repeat this sublimation, in this manner, many times until in the end, the manganese will all remain fusible in the bottom. 
This is the medicine that tints crystal and pastes in a diaphanous red color and a ruby red as well. Use 20 oz of this medicine per ounce of cristallo or glass, but more or less may be used accordingly to govern the color. The manganese should be the very best from Piedmont, so that it will have the effect of tinting the glass a beautiful ruby color and be a sight of wonderment.



[1] Manganese carbonate, MnCO3.

Friday, November 4, 2016

Benedetto Vanda

View of Badia Fiesolana - Gaspar Van Wittel called 'Vanvitelli' (1652/3-1736)
(Click  to enlarge)
Early seventeenth century  Catholic priest Antonio Neri is remembered for his 1612 book on glassmaking recipes [1] and more recently as an alchemist quite competent in the field of chemical investigation.[2] A great deal has been learned about his life, but one of the enduring mysteries is the question of his religious order. The Archdiocese of Florence records for this period were largely destroyed in a fire and no definitive evidence has ever been found concerning his specific affiliation with the Church. [3]

There were dozens of practicing orders in and around Florence at the time and none of them present an obvious fit for a group that would be engaged in the education of a young alchemist. Contemporary records yield a handful of clues, each with its own set of merits and problems. Here we will take a closer look at just one of those possibilities. 

In 1614, at the age of thirty-eight, Neri apparently died rather suddenly, of a cause that is not known today. Folklore tells that he had previously promised to reveal the recipe of the philosopher's stone to his sponsor, Prince Don Antonio de' Medici. The 'stone' was conceived to be a substance with miraculous powers including the ability to transmute base metals into gold and to cure disease. The story tells that Don Antonio was delayed in coming to Neri's side and the secret died with the priest.

On the Prince's orders, interviews were conducted by fellow alchemist and disciple Agnolo della Casa.[4] In his notes, Della Casa remarks that a "relative of F. Benedetto Vanda, Carmelite of S[anta] M[aria] Maggiore, confessor of P[riest] Antonio Neri" was suspected by Don Antonio of stealing the secret of the philosopher's stone from Neri on his deathbed. [5] Setting aside for the moment the issue of a dying man's whispered secrets, this passage provides us with the name of Antonio's regular confessor, Benedetto Vanda. It establishes that Vanda was a Carmelite and it seems that Neri was attending Santa Maria Maggiore, [6] the Carmelite run church just west of the baptistery in Florence. [7]

Another earlier document names Vanda as Parocchiano (parish priest) of the abbey called Badia Fiesolana at San Domenico outside the city of Fiesole, located in the Tuscan hills just to the north of Florence. [8] Beyond these two references, Vanda seems to disappear into the mists of time. [9] While Priest Neri was free to pick anyone qualified to hear his confessions, a likely choice would have been a leader in his own congregation. Vanda's monastery lies three kilometers, less than two miles as the crow flies, across the hills from the villa in Serpiolle once owned by the Neri family and a similar distance to his childhood residence in Florence on Borgo Pinti. The route was an easy walk, even if uphill. [10]
Here the evidence takes a twist. While Vanda was the parish priest at Badia Fiesolana around the time of Neri's ordination, the monastery itself was run not by Carmelites, but by Canons Regular of the Lateran, [11] an Augustinian sect. The two orders are unrelated and report through different hierarchies. Why a Carmelite should be leading an Augustinian [12] institution is not clear. [13] However, the abbey was heavily patronized by the Medici family. They paid for extensive construction, renovation and expansion projects dating back to the fifteenth century. When the bishop of Fiesole moved to a new cathedral in 1439, the abbey was given to the Canons. If Neri did serve his initial training for the priesthood here, his novitiate, perhaps his career was already under Medici direction. In earlier times Cosimo the Elder and Giuliano de' Medici had private contemplation cells at the abbey. The Medici funded library there had been a long-time meeting place for humanist intellectuals, as was the Medici Villa half a kilometer away. Marsilio Ficino and others met there regularly. [14] Giovanni Pico della Mirandola, a student of Ficino and a friend to Savonarola, was sheltered by Lorenzo de' Medici in a nearby house. Pope Innocent VIII would have rather seen him tried for heresy, but the pope allowed the Medici to harbor him under special considerations.
The way of life of the Canons Lateran is a good fit for Neri. Their houses were self-governing. They followed the rule of Augustine of Hippo independent of the main Augustinian order. The Priests did not serve congregations. They acted independent of each other; they went into the world and did physical work with the laity. There is no ready evidence implicating the canons at San Domenico in the practice of alchemy, which makes them a less attractive possibility for Neri. However, their specific mandate was to relieve the suffering of the sick and the poor. This mission would have been satisfied with ease by producing medicinal remedies at Don Antonio’s Casino. 


[1] L'Arte Vetraria, Neri 1612.
[2] Rodwell 1870.
[3] Florentine Archdiocese records prior to 1650 were destroyed in a fire. See Zecchin 1987–89, vol. 1, p. 169, note 12.
[4] Casa 1614. Cf. Galluzzi 1982, pp. 53, 54.
[5] See Grazzini 1983, pp. 217, 218. 
[6] Not to be confused with San Pier Maggiore, Neri's childhood parish church.
[7] See Galluzzi 1982, p. 53; Casa 1614; cf. Grazzini 1983, pp. 217, 218.
[8] AOI 1587–1591, cf. Butters 1996, pp. 415, 416. 
[9] I have not been able to find any other reference to Benedetto Vanda, which may not be his birth name, but one chosen when he joined the Carmelites.
[10] The Badia Fiesolana [Abbey of Fiesole] is located in San Domenico, about halfway between Florence and nearby Fiesole.
[11] The Canons Regular of the Lateran (C. R. L.), their full title is Canons Regular of St. Augustine of the Congregation of the Most Holy Savior at the Lateran. They occupied the monastery from 1440 until 1778.
[12] Although ancient in origin, the Canons Regular of the Lateran adopted the rule of St. Augustine of Hippo.
[13] The two groups did share use of the liturgical 'Carmelite Rite' practiced at mass. 
[14] Canons lateran Matteo Bosso, see Mutini 1971; Timoteo Maffei see Moroni 1879. The canons hosted humanists Pico della Mirandola, Angelo Poliziano, Roberto Salviati, Demetrio Calcondila, Marsilio Ficino and Lorenzo de’ Medici.
*This post first appeared here 12 Nov 2014.

Wednesday, November 2, 2016

Lake of Flowers

'The Miracle of the Immobility of Santa Lucia'
Leandro Bassano, using Florentine lakes.
In the final part of Antonio Neri's 1612 book on glassmaking, [1] he presents several recipes that are devoted to pigments for painting. His intention for including them is for their application on glass objects, but these were the same materials used in general by fine artists in the early seventeenth century. 

In his recipe #110, the Florentine priest gives a wonderfully simple method to extract the color from common flowers. The term for these pigments is "lakes." Once obtained, the pigments were often used to dye a powdered carrier material in order to give them more body and behave like other paint. From there they might be mixed into egg-tempera, varnish or oil depending on the application. It is likely that Neri used similar pigments for the illustrations in his 1598 manuscript.[2] Here is his recipe in its entirety: 


A Way to Extract the Lake [3] and Color for Painting, from Orange Blossoms, Red Poppies, Blue Irises, Ordinary Violets, Red Violets, Carnations, Red Roses, Borage Flowers, Day Lilies, Irises, and From Flowers of Any Desired Color and the Greens of the Mallow, the Pimpernel and All the Plants. 
Take whichever flower you want, of any color you want, or even a [green] plant. If it will rub green from a leaf onto white paper staining it with color, then it will be good. The plants and flowers that do not show this effect are no-good. Put ordinary aqua vitae into a glass urinal, with a cappello [alembic cap] for its cover, making sure the said crystallo cap is as wide as possible. 
Into this cap, pack the leaves [or petals] of any flower or plant from which you want to release and extract the tincture. Now lute the mouth joint of the cap. Fit a receiver to its snout and lute that joint. Give it a moderated fire so that the volatile part [alcohol] of the aqua vitae rises into the alembic, and falls down into its volume upon the petals of the flowers, extracting the tincture. 
In time, drops will run down the snout of the cap into the receiver, colored and charged with the tincture. Once all of the volatile part of the aqua vitae passes and becomes colored, distill this colored volatile part of the aqua vitae in a glass vessel. [The alcohol] will pass white and will be useable three more times. The dye will remain in the bottom, which you should not allow to dry too much, but just moderately. Then you will have the very best tincture or lake for painting from an abundance of flowers and plants.

The "aqua vitae" he refers to is simply a distilled alcohol such as grappa. The important point here is that it is a potent solution of ethanol and water; a well-known modern equivalent would be vodka. The chemical apparatus he describes is about as simple as it got for alchemists. It has three parts; the first is a base consisting of (in this case) a urinal—an inexpensive and convenient glass container with a wide mouth. The second piece is what Neri calls a "cappello"; it is a special glass cap featuring a long tubular snout leading from the top, angled slightly downward. When the cap is affixed to the base with the materials inside and gently heated, vapor will condense in the cap and run down the snout for collection in the third piece, a "receiver" vessel. 

The material he uses to seal the pieces together was called "lute," a mixture of mud, cloth fibers, egg and some other materials that stick to the glass and withstand the heat of the fire. Its only purpose was to keep the glassware sealed until the procedure was complete. [4] 

In the mid nineteenth century, Mary Merrifield made an extensive survey of Italian manuscripts with recipes for artists. She included this comment about Neri's home town:
Florentine lake must have had considerable reputation in Venice, since Leandro Bassano contracted to employ it in his picture of the 'Combat of the Angles,' painted for the church of S. Giorgio Maggiore at Venice in 1597. [5]
Today, this painting is known as 'The Miracle of the immobility of Santa Lucia' and is shown at the top of this post.

[1] L'Arte Vetraria, Neri 1612.
[2] Discorso, Neri 1598-1600.
[3] Neri uses the word "lacca," the equivalent of "lacha" in other manuscripts. For a specific reference to Neri in this regard, see Merrifield 1849, v. 1, p. clxxxi.
[4] A word to the wise: high proof alcohol in a confined glass container near an open flame is a good way to cause a minor explosion and a fireball featuring glass shrapnel.
[5] Merrifield 1849, v.1, p. clxxxiii. She references Cicogna  1824–1858, v. 4, p. 349 for this information. 
* This post first appeared here on 14 Oct 2014.