Wednesday, September 30, 2020

Neri the Scholar


Francesco Bartolozzi, Laurentian Library in the 18th cent.
(click to enlarge).
Whether one's chosen field was medicine, law, religion or alchemy, in the late fifteenth and early sixteenth century, books played as important a role in education as they do today. The schooling of Florentine priest and glassmaker Antonio Neri was no exception. The details of his training at seminary remain elusive, but there is no mistaking that his introduction to alchemy occurred well before his ordination as Catholic Priest around 1598. [1] Since his father was the celebrated physician to Grand Duke Ferdinando, there is a good chance that Antonio had access to wide variety of Medici resources, not the least of which was the famed Laurentian Library, designed by Michelangelo and run by Neri family friend Baccio Valore. [2]  

But we need not look as far as the Laurentian, which was only a ten-minute walk from the Neri household. Closer to home, in fact inside his home, there was the extensive library of his own father. At the turn of the century, it contained 477 volumes, spanning poetry, philosophy, the Greek classics, medicine, pharmacology, surgery, religion, even grammar. [3] We know this thanks to an inventory taken at the time of the physician’s death, leaving a list of titles that has survived the ages, even if the volumes themselves have long been dispersed or lost. At the time, outside of the royal family, it was probably one of the largest collections of books in private hands in Florence. Neri’s father had himself been in charge of the revision of the Ricettario Fiorentino, [4] the gold standard of doctors and apothecaries throughout Europe for medicinal prescriptions, published in 1597 and again without revision in 1623.

Antonio Neri is known best as an artisan who worked with his hands. No evidence has been found to place him at a specific monastery or university classroom. Nevertheless, what emerges from the details that we do have is a picture of a man who was steeped in a literary, scholastic tradition from an early age. His Mother’s father, Ser Francesco, held a degree in law as did her grandfather and great-grandfather. [5] Antonio’s father held a degree in medicine from the “Studio Fiorentino,” the forerunner of what today is the University of Florence.[6]  In addition, it would be reasonable to assume the household library included titles once owned by his grandfather Jacopo, a noted barber-surgeon who was known among the literati. It has been speculated that Jacopo’s best friend in the world [7] was poet Lodovico Domenichi, who wrote of his friend in a sonnet:

Marvel about you the people do,
Over how, one might say, almost stupidly,
So many lecturers and scholars admire you. [8]

Domenichi who had been appointed court historian by Grand Duke Cosimo I de’ Medici, goes on in the sonnet to name a list of mutual friends that includes poets, playwrights and intellectuals of the day.

In a similar way —that is through legal records—we know the contents and titles of the alchemical library of Neri’s sponsor, Don Antonio de’ Medici at the time of his death in 1621. These included several manuscripts by Neri himself, as well as his book on glassmaking. [9] However, one title did escape the attention of the bean-counters; sixty years after Don Antonio’s death, at the death of his son, Giulio, a handwritten book of recipes by Neri was found along with a box of elixirs. “Among them there was a booklet, entitled: Material of all the compounds of Priest Antonio Neri; there is a red dustcover, which says “experiments.” [10]

In his twenties, after a couple of years of making glass in Florence, Neri moved to Pisa where he assisted at the Medici’s furnace run by Niccolò Sisti. Pisa was home to a thriving university, with ample study possibilities, and Neri was proving himself a life-long researcher. From Pisa, in early 1604 he embarked on a seven-year long residence in Antwerp, where he stayed with his friend Emmanuel Ximenes. Ximenes was one of the wealthiest men in Flanders and maintained an extensive library in his palace. He owned many volumes devoted to the chemical arts. [11] In fact, his collection of books was probably the largest in the entire region. [12] Here too, the full list of books is preserved in an inventory compiled after the death in 1617 of Emmanuel’s wife, Isabella da Vega. 

Upon Antonio’s return to Italy, he published his glassmaking recipes in L’Arte Vetraria and then appears to have focused his attention on chemistry and medicine. In the last manuscript he is known to have written, within a year of his death, he writes of a recipe copied “from an old book, here in Pisa” in 1613. 

[1] In his manuscript Tesoro del Mondo devoted to “all of alchemy” (Neri 1598-1600) Neri self-identifies as a priest.
[2] Bartolomeo di Filippo di Niccolò Valori [il giovane] (1535–1606). He was keeper of the Laurentian, steward of the Medici herbal (simples) garden and an early director of the Accademia delle Arti del Disegno. He was a personal friend to Antonio Neri’s father and godfather to his first child (Antonio’s older sister) Lessandra.
[3] Bec 1984, pp. 299–310.
[4] Neri, Benadù, Rosselli, Galletti 1597, 1623.
[5] Ser Francesco di Ser Niccolò di Ser Antonio Parenti (1519 - ?)
[6] Fathers medical degree ref.
[7] . Garavelli 2004, p. 82, n. 186.
[8] Domenichi 1555, Stanza 7.
[9] Covoni 1892.
[10] Ibid p. 193.
[11] Duverger 1984.
[12] Dupré, Lüthy 2011, p. 272; Göttler, Dupré 2009.
* this post first appeared here on 31 Dec 2014.

Monday, September 28, 2020

An Alchemist's Kitchen


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 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 Neri's later claim to fame: glass—its most notable appearance in Tesoro  is in illustrations of 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] To outsiders, the Neri's were a wealthy and quite well respected family, but internally, the tragic events undoubtedly threw their lives into turmoil. It is in these circumstances that Antonio started his manuscript. The events allude to the reasoning behind a cryptic Latin quote scribbled at the top of a page above the first recipe of Tesoro: "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. 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. The scene 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 Allesandro, 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 one sense, the methodology of alchemy lives-on today in kitchens around the world. 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 ( dated 13 June 2014.
[4] Neri 1598-1600, ff. 7r, 8r, 9r, 10r.
* This post first appeared here on 27 August 2014,

Friday, September 25, 2020

Renaissance Lapidaries


Antonio Neri, Tesoro del Mondo, 1598-1600
f. 7v, "Ars Preparatio Lapidum"
In 1598, in his early twenties, before his glassmaking career began, Antonio Neri completed an extraordinary manuscript. Tesoro del Mondo or 'Treasure of the World' was devoted to all aspects of alchemy and was intended for publication, but it never saw a printer's ink. By a minor miracle of providence, the manuscript survives today, in the special collections department of the University of Glasgow Library. The pages include a set of fascinating images, this one (left) among them.   Labeled "The Art of Preparing Stone," the picture shows five men working with various pieces of equipment related to the art. [1]

In the upper-left a lapidary works at a polishing wheel. It turns at low speed, driven by a belt which is powered from below, possibly by a foot pedal. The artisan holds two polishing fixtures against the surface of the disk, while four more stand at the end of the table. Under this workstation is an inscription in Italianate Latin that reads "Accontiare et lustrare pietre praciose" [preparing/dressing and polishing precious stones]. Behind the lapidary are shelves holding finished pieces. They range from small objects that appear to be rings, to cups, vessels and large bowls, presumably all made from stones, gems or minerals. 

Proceeding clockwise to the upper-right side of the image, we arrive at a worker tending a furnace with iron tools. Inside is a crucible sitting in the flames. Below is the firebox, and underneath that is the word "Calcinare" [calcination], which in Neri's parlance refers to the process of breaking down a material into a powder usually through the use of heat. Neri uses this method extensively in his glass formulations; in his book L'Arte Vetraria, [2] almost every colorant discussed is a metal which requires "calcination" before use in the glass melt. In the case of stone, Neri uses the furnace to make the main ingredient of glass. He breaks down quartz stones into powder by repeatedly heating them and then quenching in cold clean water. The rocks fracture into coarse granules which are then ground into a fine powder.

The middle-right of the illustration shows a worker checking on a distilling apparatus. This consists of a small stove and three pieces of glassware.  The "body" holding the raw material to be evaporated or sublimated is capped by a "head" that sports a long snout leading to a "receiver" vessel which collects the finished product.  Stills were useful in producing everything from alcoholic spirits like grappa to acids and reagents. Their specific use in stonework is not clear, possibly in dissolving precious metals from the constituent minerals in stone.

The lower-right portion of the image depicts two men seated at a low bench, each holding specialized tools used to shape "alabaster, marble and porphyry." Finally, in the lower-left we see a specialized mortar and pestle used to grind stone and minerals into a fine powder.

The two benches and the distilling stove all bear a distinctive diamond shaped insignia with a small circle at its center. The two men in the lower portion of the illustration appear to be working on a stone inlay version of this same pattern.  The implication is of an identifying symbol, but a specific affiliation is elusive.

 This technique of creating designs entirely in colorful gems and minerals (pietre dure) is an ancient one revived by the Medici family, specifically by its first three grand dukes.  In the 1560s Cosimo de' Medici employed two such artisans (commessi) in the courtyard of the Palazzo Vecchio. By the 1570s a larger group was working out of Francesco de' Medici's new palace, the Casino di San Marco. In 1588 Ferdinando de' Medici moved them into the Galleria dei Lavori [Gallery of Works] at the Uffizi Palace where they were named the "Opificio delle Pietre Dure." [workshop of hard-stone]  There the organization thrived and refined the art of creating inlaid stonework to the point of producing realistic life-like scenes. Their work graces the most opulent spaces in Florence, including the Chapel of Princes and the interior of Santa Maria del Fiore. The Opificio delle Pietre Dure continues to operate to this day. The organization has been charged with the maintenance and conservation of many of Italy's great works of art. They maintain a worldwide reputation for excellence. [3]

It seems well within the realm of possibility that Neri's illustration indeed depicts an early incarnation of the Opificio. The artisans working in Pietre dure were handling precious materials and as such might not be readily accessible to the general public. The fact that Antonio Neri's father was a prestigious member of the Medici royal court all but ensured his entree to the royal workshops.

[1] Neri 1598-1600, f. 7v.
[2] Neri 1612.
[3] Official website:
* This post first appeared here in a slightly different form on 3 Sept 2014.

Wednesday, September 23, 2020

Alchemy of Plants

Antonio Neri, Tesoro del Mondo, f. 9r.
"Arts Preparatio frugu vel Piantar."

In a 1598 manuscript devoted to "all of alchemy", Antonio Neri singled out four particular practices, each of which he made the subject of a detailed illustration. Each is devoted to a different "art"; preparing animals, stone/minerals, plants and metals. The manuscript was produced over a period of two years starting when he was just twenty-two years old. He began writing shortly after his ordination as priest and the work was completed before he was employed making glass for the royal Medici family in Florence. 

Neri is best known for writing the first printed book of glassmaking recipes, so we might expect to find that subject covered in the early manuscript, but nothing appears aside from a single recipe for artificial ruby which makes use of glass. Indeed, the general conclusion of historians is that his involvement in making glass did not start until 1600 or 1601. Absent of any direct citation of that art, the manuscript does show a familiarity with the kind of individual skills required. Among the things Neri would need to know was the ability to make "glass salt" from certain dried plants. Presently we will look into the third of the illustrations mentioned above, which he titled "The Art of Preparing Fruits or Plants." [1] All of the activities depicted here relate to food and drink, yet they could easily be applied toward other purposes.

While there is scant reference to glass in the text, the pictures are filled with examples of specialized vessels for chemical production and investigation. From these figures we know Neri at least received an exposure to the glassmaking profession earlier. He must have started his training in alchemy as a teenager while still studying for the priesthood. This is not hard to imagine since his father was the chief physician to the grand duke of Tuscany, and would have a strong grounding in alchemical techniques for producing medicines. Indeed, the first sentence of Antonio's 1612 book on glassmaking, L'Arte Vetraria, begins: "I have spent years of my youth laboring around the glassmaking craft, and experimented with many fine and marvelous effects." [2]

At center-left of the illustration at hand, we see a male farmer holding a flail, perhaps going about the business of threshing wheat, which appears in a bale behind him. Figuring prominently above the farmer (upper left) is a large mechanical apparatus that appears to be a gristmill powered by a waterwheel. A conical bag feeds grain or possibly corn from above into the central hole of a horizontal grinding stone supported by a large rectangular box. We can easily imagine that the gears shown on the front of the box control the drive or the gap between the stones. Wheat, of course, was an ancient well established staple. Corn was introduced as a direct result of Columbus' voyage to Cuba and by Neri's time, corn was being widely cultivated throughout southern Europe, northern Africa, and even as far as China.

Returning to the illustration, on the immediate left of the mill is a woman, who we can guess, is fashioning rolls or small loaves of bread from dough made with flour from the mill. Below her, (center right) is a boy using a long paddle to put the balls of dough into a baking oven. In effect, Neri is showing us the full chain of events from harvesting to finished baked goods. 

Further down, another woman works over a large basket of herbs, which appear destined for three large glassware stills to her right. In his book, Neri presents numerous recipes for extracting paint pigments from flowers using similar methods.

At the bottom of the illustration, a third woman stands in a large wooden tub crushing grapes with her bare feet, as grape juice runs into a pan on the right. To her left are three wine barrels standing side-by-side. 

For us, the connection to alchemy might seem tenuous with the possible exception of the distilling stations. For Neri, there was a deep lesson here about the way nature works; in his later manuscript Discorso, he uses the growth of grain as a metaphor for "multiplying" the "seeds" of gold inherent in primordial material left over from the creation of the world. 

This is confirmed by the example of seeds, of which a single grain is capable of producing a hundred or a thousand, as long as you sow them in a commensurate place. Take the further example of fermentation, in which one small part is sufficient to ferment a large mass. Nor is it contradictory to say that the metals do not produce seeds, like herbs and plants, because even though nature by itself has no power to take the seed out of gold, however, aided and encouraged by art, [nature] will do that which it does not do by itself. So that art begins where nature ends, and art will perfect the seed, which in gold is merely begun. [3] 

Given knowledge of how to work in harmony with nature and bring about the right conditions, he was convinced that a small quantity of material could be converted into a large amount of precious metal. The illustration on the art of preparing plants simply showed a different manifestation of the same principle; he is showing how grain multiplies in the fertile earth, it is then transformed through the addition of water and fire into nourishment.

[1] Neri 1598–1600, f. 9r.
[2] Neri 1612, p. ii.
[3] Grazzini 2012, p. 454, (Neri, 1613).

* This post first appeared here in a slightly different form on 10 Sept 2014.

Monday, September 21, 2020

Veins of the Earth


Antonio Neri, "The Mineral Gold"
Neri 1598-1600 (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. 

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. 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 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 1598-1600 (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." 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."  

At base, this 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 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, September 18, 2020

Glassware of an Alchemist


Antonio Neri (1598-1600),
"Libro intitulato Il tesoro del mondo" f. 38
In the introduction of L'Arte Vetraria, his 1612 book on glassmaking, Antonio Neri discusses the technical and scientific uses of glass. He rattles off an impressive list of items, many of which are still in everyday use in chemistry and medicine:
Beyond the ease and low cost with which it is made, and the fact that it can be made anywhere, glass is more delicate, clean, and attractive  than any material currently known to the world. It is very useful to the arts of distillation and spagyrics, not to mention indispensable to the preparation of medicines for man that would be nearly impossible to make without glass. Furthermore, many kinds of vessels and instruments are produced with it;   cucurbits,  alembics,  receivers,  pelicans,  lenses, retorts, antenitors,  condenser coils, vials, tiles, pouring-vessels (nasse),  ampules, philosophic eggs  and balls. Countless other types of glass vessels are invented every day to compose and produce elixirs, secret potions, quintessences, salts, sulfurs, vitriols, mercuries, tinctures, elemental separations, all metallic things, and many others that are discovered daily. Also, glass containers are made for aqua fortis and aqua regia, which are so essential for refiners (partitori) and masters of the prince’s mints to purify gold and silver and to bring them to perfection. So many benefits for the service of humanity come from glass, which seem nearly impossible to make without it.
The glass book, as it was published by Neri, did not contain any illustrations. If we hunt around in the alchemical literature and in museums, we can find examples of the apparatus and vessels on his list, but still, we might feel disappointed at not seeing the specific pieces with which our glassmaker was referencing. As it happens, we actually can see a number of these pieces, exactly as Neri experienced them. Over a decade before writing  the glass book, when he was just completing Catholic seminary to become an ordained priest, Antonio Neri wrote a manuscript devoted to "all of alchemy" in which he shows us many of the same glass vessels. Here he lists and shows us (in the illustration, from left to right, top to bottom) a double vase, a urinal (yes, that kind of urinal), a pair of Florence flasks (the Italians now call this a pallone di Kjeldahl), a philosophic egg, another flask which Neri calls a "bozza longa," an alembic (or still-head), a retort, a bottle,  mouth-to-mouth urinals, a receiver (for a still or retort), a saucer, and assorted cups and ampules. Since many of these terms changed from place to place and over time, we can use this chart to get a much better idea of exactly what Neri was doing in his recipes. The use of urinals in his chemistry kit shows simple practicality; these were standard items made by glass factories. If a low-cost, readily available item could be used in the laboratory, so much the better.

Many of the items Neri lists were used in distillation, which was a basic technique of alchemists. A still could be set up in any number of variations, depending on the intended product, which could range from alcoholic spirits to powerful acids and other reagents. The "athanor" was a stove specially engineered to gently heat a large flask, called the "cucurbit," which contained whatever was to be distilled. The apparatus would include an "alembic"; a cap that fits on top of the cucurbit with a snout-like tube running downward from its top. The idea was that volatile ingredients would evaporate inside the cucurbit, rise up, condense in the alembic and run down its snout, to be collected in a "receiver" vessel. Sometimes, for convenience, all three pieces (cucurbit, alembic and receiver) are together referred to as the alembic. The process could be sped up significantly by adding a condenser coil, what Neri calls a "serpentine." As steam built up in the cucurbit, it was routed through its snout to a coiled tube that might be submerged in cold water. This way, the steam would condense more rapidly, sending more liquid to the receiver. Neri uses this method to produce acids in order to dissolve metal pigments for his glass, but the same basic technique is still applied today in producing industrial chemicals, medicines, perfumes and alcoholic drinks such as moonshine, brandy, vodka, rum and whisky. However, in the distillation of alcohol, metal (usually copper) containers are preferred. Neri was often producing chemicals that would react with metal, glass provided a very good solution to this problem but as he discusses at length, great pains must be taken to ensure that the glass vessels do not crack or break when heated or cooled too suddenly.

* This post first appeared here on 27 December 2015.

Wednesday, September 16, 2020

Women and 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, celebrated glassmaker and alchemist Antonio Neri provides us with further detail, even if raising more questions than answers. One of his manuscripts, entitled Tesoro del Mondo (Treasure of the World) depicts three women running chemical equipment. Unfortunately, we are left to guess who they were and what role they played in the larger Florentine technical arts community. 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, 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 in Florence, 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.

Monday, September 14, 2020

Alchemist's Assistant


Spine of volume 3 of Della Casa's notebooks,
Biblioteca Nationale Centrale Firenze.
At the turn of the seventeenth century, when Priest Antonio Neri was employed in Florence by the Medici prince Don Antonio, he worked closely with another alchemist by the name of Agnolo della Casa. Casa chronicled Neri's work and after his colleague's death in 1614, he undertook a special mission for Don Antonio to interview Neri's other associates and uncover the priest's recipe for the philosopher's stone. Don Antonio went as far as consulting a medium in Venice to contact Neri in the afterlife, but that is a story for another time. 

Thousands of pages of notes relating to Antonio Neri's work in Florence were recorded by fellow alchemist Agnolo della Casa. A significant portion of this nineteen-volume manuscript is devoted to Neri's work on transmutation and specifically on the fabled philosopher's stone. The trouble is that he wrote much of it in obscure language, which renders it among the most cryptic in the entire canon of alchemy. Other sections of Della Casa's notebooks contain copies of the works of various adepts including Geber, Ramon Llull and Arnold Villanova. Neri took a keen interest in all of them.

In 1597, Prince Don Antonio de' Medici occupied the dormant Casino di San Marco and made it his new home. His father, the former grand duke, built this combination palace and laboratory on the north side of the city to indulge his own fascination with natural secrets. Don Antonio began to assemble a team that included Neri and Della Casa. The three men were all about the same age, in their early twenties, ready to do great things; ready to reveal nature and change the world.

In their time, it was reasonable to think that one metal could be 'purified' into another and that a single medicine could cure all disease or counteract any poison. These notions had been around since ancient times. In this realm, a skeptical eye was an absolute necessity, but there was no specific evidence that disproved the old stories. Don Antonio reportedly spent a fortune collecting recipes and testing them; he and his men worked to separate the real from the bogus. Swindlers and con men were in plentiful supply; they hawked miracle cures in public squares throughout Europe. Without a firm grasp of the underlying chemistry, the task of understanding a particular compound or chemical reaction could be quite difficult. Even to experienced, careful researchers, there was no guarantee that conclusions were correct.

Don Antonio was convinced that the glassmaking priest had indeed discovered the secret of transmutation. He put Della Casa to work interviewing Neri's acquaintances to see what could be learned. An expert gold refiner, Guido Antonio Milani, reported to Della Casa that in July 1596, Neri had performed before his eyes a transmutation of base metal into "twenty-four carat" gold. He said he pressed the 20-year-old, who in reluctance, confided that he had learned the secret from a German, who performed the gold transmutation with a "tablet of medicine." The German told Neri the medicine was nothing but the simple quintessence of green vitriol and the method to produce it was described by Paracelsus.

* This post first appeared here in a shorter form on 2 Sept 2013.

Friday, September 11, 2020

Lakes of Flowers


'The Miracle of the Immobility of Santa Lucia'
Leandro Bassano, painted 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.

Wednesday, September 9, 2020

Neri and the Kabbalah


Kabbalistic Sephiroth Tree,
from Portae Lucis, Paulus Ricius (Trans.)
Augsburg, 1516.
Kabbalah is a form of mysticism practiced within the Jewish tradition. In the early seventeenth century, there was a great deal of interest in Kabbalistic teachings among Catholic alchemists and natural philosophers. It was recognized that Christian alchemy had its roots in Hermetic and earlier Arabic societies, (the word "alchemy" itself is of Arabic origin.) It was thought that the Jewish Kabbalah was yet another branch of the same traditions of relaying secret knowledge by word of mouth. 

In early modern Florence, Italy, there were some interesting connections between the Kabbalah and glassmaker, alchemist and Catholic Priest Antonio Neri. Here is Neri’s own description, of Kabbalah in his 1613 manuscript Discorso: 
Some call it Kabbalah: in ancient times fathers communicated it to their children only by voice, preserving [this knowledge] for posterity, not for history, but as simple tradition. Others finally gave it the name of 'wisdom' [sapienza] because they rightly believed it was impossible, without this art, to know perfectly the nature and the qualities of natural bodies. In order to achieve the end they wanted, which was the perfection of the bodies, they separated the pure from the impure through various chemical operations, which can all be reduced to six principal phases.*
He goes on to describe basic chemical operations that were thought to be fundamental to purifying materials, and ultimately to the production of the Philosopher's Stone. These techniques are the same as practiced in Christian alchemy, and Neri uses them in his glassmaking recipes. Clearly, he had more than a passing knowledge of the subject, and it is interesting to speculate on how he might have come to learn about Jewish alchemical traditions. 

Early seventeenth century Florence contained a city within a city: the Jewish Ghetto. A walled perimeter encircled what is now the Piazza della Republica. This was the mandated home for all of Florence's Jewish population. Each night, entrance gates were closed and locked from the outside. Within the Ghetto, residents were allowed to live and warship freely, even maintaining a Synagogue. In the daytime, the gates were opened, and residents were allowed to go about their business and leave the city with special passes. Among the Ghetto's most prominent residents was the family of alchemist Benedetto Blanis (c.1580-1647.) Blanis served as librarian to Medici prince Don Giovanni. Giovanni maintained an alchemical laboratory in his residence, which was run by Blanis, located only a short distance from where Antonio Neri was living when he first worked at the Casino di San Marco.  

Don Giovanni maintained a close relationship with Neri’s benefactor Don Antonio de' Medici. So close, in fact that when two of  Blanis' relatives were implicated in a gambling scheme, Don Antonio hid them at his residence and then spirited them away, out of Florence, in his own coach until matters cooled off. Furthermore, Blanis came from a family of doctors who must have been known to Neri's father, royal physician to Grand Duke Ferdinando. Antonio Neri was probably a couple of years older than Blanis, if they did not meet through mutual connections with the Medici family, then perhaps they met on the street. The walk for Neri, between his living quarters near Santa Trinita, and the Casino laboratories would have passed around or through the Ghetto, and the walk for Blanis to Don Giovanni's palazzo on Via Parione took him past Neri's front door. The paths of the two men may have crossed, but there is not direct evidence.

Of course, in the absence of hard facts, there are many other possibilities of how Antonio Neri might have become acquainted with Kabbalistic tradition. By taking a look at Blanis and his connections to the Medici family, we can at least see an area of cooperation between Jewish and Christian alchemists in what we might otherwise assume to be an inviolable separation.** 

* “Discorso sopra la Chimica: The Paracelsian Philosophy of Antonio Neri”, M.G. Grazzini / Nuncius 27 (2012), p. 337.
For more on Blanis, see Edward L. Goldberg, The Secret World of Benedetto Blanis. (2011).
** This post first appeared here on 6 January 2014.

Monday, September 7, 2020

1600s Glass Furnace


From "De re metallica" 
Agricola (Georg Bauer) 1556.
In the seventeenth century, glass furnaces represented a pinnacle of technology. True, the ability to achieve the high temperatures required to melt glass had been around for centuries – high enough to melt gold, silver and copper as well. What made the glass furnace remarkable was its refinement. It made efficient use of its hardwood fuel and was able to maintain a controlled, even temperature long before any thermometer could measure it. In fact, in the early seventeenth century, Galileo was only just beginning to use glass bulbs and tubes to measure differences in ambient room temperatures.

In Florence, the construction used was typical of the time throughout Europe, called a "beehive" furnace because its shape resembled the classic elongated dome of a beehive. A double wall, built of fire resistant bricks, provided further insulation, trapping heat inside. Vertically, the furnace was divided into three levels, each forming a wide open chamber. The bottom space was used to build the fire, and had one or two openings to the outside, used to add wood fuel, rake the coals, or shovel out ash. The second, central level was where the pots of glass resided. A central hole or "eye" on the floor directly exposed the fire pit below. The space directly next to the eye was the hottest, and temperature could be further controlled by moving the crucibles farther away or closer to the eye. A number of openings in the wall allowed gaffers access to the glass pots, and at least one larger opening was used to place new crucibles, or rearrange the existing ones. The upper chamber was used to control the draft, and sometimes for annealing. Again, a central hole in the floor of this (top) level allowed exhaust gasses to leave the glass chamber and an opening to one side vented the exhaust.

In his 1612 book, L’Arte Vetraria, Neri is careful to stress that only dry oak or other hardwood should be used because it burns cleanly, and will not deposit ash or creosote in the glass.
The furnace should have dry wood, hard wood of oak because soft wood tinges the furnace and does no good. Stoke it steadily and continuously so that the flame is always clear, and there is never any smoke, which is very important in order to make a beautiful cristallo.
Once a finished piece of glassware is made, it must be allowed to cool slowly, over a period of many hours. This was often accomplished by building a long enclosed horizontal trough that connected to the furnace. A draft opening at the far end allowed heat from the furnace to be drawn in, and finished pieces were placed in a pan at the furnace end and then slowly pulled by a chain further and further down the trough toward the cooler end. This "annealing" process ensured the glass would not develop stresses and crack as it cooled.

Although Neri does not concern himself with the vagaries of furnace construction in the book, it is clear that he did possess considerable knowledge on the subject. Several of his unconventional methods for making pigments for glass involve taking bricks out of the furnace wall to stash chemicals for long term exposure to the heat.
Take small pieces of copper and put them inside the arches of the furnace. In that place, they will be within the walls. Leave them that way until each piece of copper is well calcined, using a simple fire.
While it is true that artisans of the early seventeenth century did not possess the same understanding of nature that we now enjoy, they did have a working knowledge that served them very well. It was backed by a theoretical framework that was quite sophisticated and was consistent with what could be observed and measured at the time. This is no different from our own modern understanding of nature: sophisticated and consistent with what we can observe and measure.

*This post first appeared here 24 January 2014

Friday, September 4, 2020

Early American Glass Poem

Note: This is an abbreviated version of a piece appearing in the Autumn/Winter 2016 issue of the NAGC Bulletin. Many thanks for their permission to share it here. A copy of the complete article is available through inter-library loan from the numerous public and art museum libraries which subscribe to this journal, (including the Rakow Library at The Corning Museum of Glass). The Bulletin can also be obtained directly from its publisher, the National American Glass Club.

Glass: A poem by Henry Schoolcraft

In the final years of the 1700s, a third generation family that was living in New York’s Hudson River Valley welcomed a new son, Henry Rowe Schoolcraft (1793-1864). They welcomed him into a newly formed country, brimming with promise and expectation, the United States of America. His father was the superintendant of a new window glass factory near Albany. The family boasted a long line of military men, but perhaps more importantly, a long line of adaptable, self-motivated, life-long learners and young Henry was no exception.  

With the help of his father and like-minded family friends, Henry parlayed a rural education into private instruction in Latin, a premier collection of scientific books, and a museum quality mineral collection.  In 1809, at the age of 16, he started a hand-written literary magazine called “The Cricket” in which he published short pieces of prose and poetry among a circle of friends. His time at Union College was cut short by the opportunity to manage a glass factory further west on the shores of Seneca Lake, near Geneva, New York.

Along with his father, Henry went on to become one of the most sought after glass factory guru’s in New England. In 1814, he was running the Vermont Glassworks on the shore of Lake Dunmore. He had set up an experimental furnace with Prof. Frederick Hall from the college in nearby Middlebury.  Henry used the facility to research glass composition for a hefty book he was writing on the subject. Managing by day, experimenting by night, he still found time for his literary pursuits. It was here, in the autumn of 1814, that he composed a remarkable poem titled “Glass” in which he compares commonplace personalities of the early 19th century to the vitreous material of which he was so familiar.

Until now the poem has never been published beyond the first few stanzas.  “Glass” runs for 268 lines of rhyming couplets in a lose meter. The handwritten manuscript is archived at the Library of Congress. It begins with an assessment of mankind: [1]

Mankind resemble glass; they are, like it,

For use or fashion, show or service fit;

Some bright and fair, some dull and more obscure,

These prized as good, those, estimed poor;
To grace a kitchen, or a parlour made,

As use is most consulted, or parade;

But all as various; and eke they are,

As frail, as brittle, and as keen a ware.

Their bases differ, as our chemists say,
This made of sand, that fashioned out of clay

Yet shall we, in both compositions find,

Similitude in beauty, use and kind.

To man, tis true some small objections lie

In point of texture and transparency,
But though we grant him, in material blind,

Yet lacks he not, transparency of mind

And we no surer faults in each detect

By rays of light, than rays of intellect.

So nice the processes, the art requires,
So pure th’ ingredients, so intense the fires,

Where tumours grow, where phthysic’s fitful breath,

Forbodes the public faith, a sudden death.

Felons, freckles, frightful fire warts,

Are all disclosed as clear as limpid quartz.

His voice and pen are graced with equal skill,

To lash, report, or advocate a bill.

Speak without nostrums, clear his throat when lost,

But ever loudest, when they shuffle most.

Alike to him, the subject, time or stage,
Fierce to discuss, and ready to engage

If finance—there Blaberius is at home

If raising troops, he votes with general glum.

In peace he’s noisy, but if wars involve’

He blasts the foe by one august “Resolve.”
Prate, prate, prate, prate! the error of the land,

His voice, by every vulgar breeze is fanned

Nor learn from Witherspoon his course to run,

The simple cause, “to stop when he has done.”

(Read full poem)

(Line numbers are referenced in parenthesis) 

The exact manuscript title as written by Schoolcraft is: GLASS, | A Satire Poem. | Lake Dumnore, 1814.

(4) Estimed: Vernacular loanword from the French, estime; valued.

(7) Eke: also.

(10) “Feet of clay” is an expression referring to a weakness or character flaw. The phrase derives from the interpretation of the dream of Nebuchadnezzar, King of Babylon, by the prophet Daniel as recounted in the “Book of Daniel.” (Daniel 2:31–33, 2:41–43).

(21) Phthisic: a wasting illness of the lungs, such as asthma or tuberculosis; phthisis. Any wasting disease. A person suffering from phthisis.

(23) Felon: a carbuncle or other localized infection of the skin. Fire warts: “The hand that reached farthest down on the shovel is burned forever with calloused fire warts.” William E. Bain, Frisco Folks: Stories and Pictures of the Great Steam Days of the Frisco Road (St. Louis-San Francisco Railway Company) (Denver: Sage Books, 1961), p. 96.

(25) In the ms, “Graced” is struck out and replaced by a word that is smeared and illegible to me.

(27) Nostrum: a medicine, especially one that is not considered effective, prepared by an unqualified person.

(31) Blaberius: possible Latinization for ‘one who blabbers’. Also blaberus: a genus of giant Central American cockroach.

(35) Prate: to talk foolishly or tediously about something.
(37) Witherspoon: John Knox Witherspoon (1723–1794).

[1] Paul Engle, “Glass, A Poem by Henry Schoolcraft” in Glass Club Bulletin, of The National American Glass Club, No. 230, Autumn/Winter 2016, pp. 5-14.