Royal Apothecary

Fresco, early 16th century speziale,
Castello di  Issogne, lower Aosta Valley, Italy.

As physician to the Medici royal family, Antonio Neri’s father (Neri Neri) worked closely with the other medical professionals in Florence. Among them was Stefano Rosselli, the royal pharmacist, who owned the Speziale al Giglio in the center of town.  We would readily recognize this shop today; rows of labeled jars lined the walls holding exotic remedies and ingredients from around the world. Freshly made sweets, cakes and other confections sat on the counter to entice customers. 

One of several such shops located around the city, ‘speziali’ dealt with medicines and herbal remedies, but also a wide variety of other needs, from pigments for artists, to the distillation of spirits, to the rental of funerary equipment, to raw materials for alchemists. Each shop had its own specialty to distinguish itself from the others. To some extent, they also competed with private operations run by convents and monasteries. Rosselli’s shop was famous for catering to the Medici family and courtiers, and as such he could command premium prices. But the function of these shops was not all business; they also proved popular meeting places for the local intelligentsia. Poetry, literary and other groups with various interests often congregated in the back rooms of the speziali.

Stefano Rosselli came from a family that was a mixture of artists and pharmacists. His father Romollo, with a degree from the university at Pisa, was a specialist in herbal remedies (simples). His brother Antonio (Fra Anslemo) worked at the pharmacy of San Marco, directly across the street from the Casino where Antonio Neri would later make glass. Their grandfather Bernardo Rosselli was a painter, a favorite of Michelangelo. Stefano’s daughter Fiametta joined the Dominicans as a nun, and became the famous sculptor Suor Caterina Eletta. A distant cousin was Cosimo Rosselli, who returned from Rome with a small fortune, earned painting for the pope. Biographer Giorgio Vasari noted that Cosimo could have lived comfortably on those earnings had the passion for alchemy not overtaken him. 

Stefano proudly maintained a proprietary list of treasured recipes gathered over a lifetime of experience. Some were given to him directly by Grand Duke Cosimo de’ Medici, his son Francesco and daughter Isabella. Between 1589 and 1593 when Rosselli was in his late sixties, he started to compile these into three notebooks, which he eventually passed down to his sons and today have survived the ravages of time. The three books are devoted to medicines, perfumes and confections. Antonio Neri was a teenager in this period, and it is easy to imagine an occasional visit to the Speziale al Giglio for a piece of something sweet, perhaps one of Rosselli’s excellent pistachio calissons.

For a transcription and French translation of the recipes see: Rodrigo de Zayas, Mes Secrets, à Florence au temps des Médicis 1593 (Paris: Jean-Michel Place, 1996).

This post first appeared here on 4 December 2013.

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.

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.

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.

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.

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.

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.