Fire, Brimstone and Glass

 

The Alchemical Symbol for Sulfur

Bright yellow elemental sulfur or “brimstone” as it was often called, occupied a central place in the cabinets of seventeenth century alchemists. Antonio Neri used it in many of his preparations and specifically in pigments for glass. When sulfur is heated with thin sheets or shavings of metal, foul smelling chemical reactions can take place that reduce the metal to a powdered compound and some of these turn out to be effective glass colorants. Neri’s 1612 book, L’Arte Vetraria, offers a variety of recipes, which specifically prepare iron and copper using sulfur to form pigments. In reality, the resultant chemicals were mixtures of oxides and sulfur compounds. Since these also chemically interact with each other in the glass melt, many different effects are possible. Modern glass artists sometimes specifically use both oxide and sulfide pigmented glass side by side in the same piece; a striking effect can be the spontaneous formation of a third color along the boundary. As Neri says in the closing line of his book:

Although I have placed here the way to make this powder with much clarity, do not presuppose that I have described a way to make something ordinary, but rather a true treasure of nature, and this for the delight of kind and curious spirits.[1]

Keep in mind that the thinking of alchemist Neri was that the sulfur acted upon the metal, but did not necessarily combine with it. From his point of view, the exposure resulted in the metal’s infusion with new properties. The Aristotelian conception of the world was that everything under the sun contained various amounts of four elemental essences: air, water, fire and earth. Sulfur was seen to be dominated by the latter two, ‘fire’ because it burned easily and ‘earth’ because it occurs as a solid.

In the sixteenth century, a Swiss physician named Paracelsus developed an extension of the four-element system. After his death, his writings enjoyed a new popularity among chemical experimenters in the period that Neri came of age. Since his teenage years, the work of Paracelsus was a strong influence on both Neri and separately on his benefactor, Florentine prince Don Antonio de’ Medici. According to Paracelsus, sulfur was one of a triad of “principles” consisting of salt, sulfur and mercury. These three had philosophical as well as physical interpretations attached to them. Besides other applications, like in medicine, the three physical materials figured prominently in efforts to transmute one metal into another. 

In fact, sulfur in particular played a starring role in a very convincing demonstration that purported to turn iron into copper. Mining operations often utilized water to clean or separate ore from tailings. Other times, water was used to keep dust down, or simply flowed naturally through underground springs. When sulfur-bearing earth is exposed to air and moisture, the result can be the formation of dilute sulfuric acid. This “vitriol” was an irritant to the eyes and skin, and very unpopular with the miners. However, in at least one location, it seemed to have a miraculous property. When this “vitriolated water” flowed out of the mine, it seemed to transform bits of iron into copper. [2]

Chemically, copper had already been dissolved in the acid, forming a copper sulfate solution. But sulfuric acid shows a preference for iron. When the copper solution flowed over iron tools, it took up the iron and dropped the copper, depositing it in a thin layer. The effect appeared to be a transmutation of iron into copper. Further testing and scrutiny confirmed that pure iron, when exposed to the mine fluids resulted in real copper. Neri for one was well aware that the vitriolated water might have arrived containing copper, as he explains in his manuscript Discorso. [3] But apparently, it did not occur to him that the water leaving the scene might have contained the iron. If he had made the connection, the observation would have advanced the understanding of both ion-exchange chemistry and the principal of conservation of matter; these were two ideas that would not be explored seriously for another hundred years.

Well into the eighteenth century, the mine at Smolnik, (now in Slovakia), was a highly touted tourist destination for chemical experimenters. [4] For some, it was considered among the strongest evidence that transmutation could and did take place in the natural world. I like this demonstration so much because it works the same way as a parlor trick; while we are so intently focused on the metal changing before our eyes, Mother Nature quietly slips the copper in with one hand and takes the iron away with the other, no one the wiser.


[1] Neri 1612, p.114.
[2] See this post for a more detailed description  http://www.conciatore.org/2014/01/turning-iron-into-copper.html
[3] Grazzini 2102.
[4] The effect had previously been described Georgius Agricola, in book 5 [9] of Nature Fossilium. See edition, transl. from the first Latin edition of 1546 by Mark Chance Bandy, Jean A. Bandy (New York: Mineralogical Society of America, 1955), p. 188.

*This post first appeared here on 7 November 2014.

Crocus Martis

The many different alchemical symbols used to denote crocus martis.

In order to understand the seventeenth century glass recipes of Antonio Neri and for that matter, any alchemical recipes, it is first necessary to have a grasp of the chemical repertoire; no degree in chemistry required. The ingredients referenced by Neri were not especially exotic, but over the intervening four centuries since he wrote, the common names of materials have changed considerably. In the current lexicon, we name materials by their chemical formulas, so iron oxide names its two constituent elements, iron and oxygen. But in the seventeenth century, the periodic table of elements was a concept yet to be invented; hence "crocus Martis." Martis refers to Mars, the Roman god of war, the red planet, and the ancient alchemical name for iron. The origins of crocus are lost, but it may refer to the similar looking spice saffron, (crocus sativus) which has been highly valued since antiquity. Poetically, 'saffron of Mars' alludes to the orange-red color of rust. 

A first encounter with the technical recipes of sixteenth and seventeenth century alchemy can be confusing, frustrating and more than a little disorienting. There is no shortage of records, letters, manuscripts and recipe books that have been preserved from that period, however, the challenge lays in making sense of them in a way that relates to our current view of the world. It is understandable that alchemical materials and compounds had unfamiliar names; but even larger difficulties arise with the realization that any given name might describe several different chemicals, and in fact, there may be several different interchangeable synonyms/symbols for any given name. As it happens, there were good reasons for this state of affairs. The challenge of deciphering alchemy is not insurmountable. Taking the time to understand really opens up a window onto a strange and wonderful landscape of history. 

Antonio Neri considered himself an alchemist first and glassmaker second. His purely alchemical works are somewhat cryptic, but in the glass book he bends over backwards to be accessible to novices. Because of this crossover, his work can help us to navigate details in both areas that might otherwise go without explanation. His writings broadly divide into two categories: one intended for generally curious readers and another intended only for those familiar with the arcane coded language of alchemy. We have examples of both styles by Neri and all written within the period of about fifteen years at the beginning of the seventeenth century. As a result, we can use his works intended for a general audience to decode some of his more arcane passages elsewhere. With the glass recipes, his careful explanations lead us to gain considerable confidence in his technical abilities. In the introduction to his famous book on glassmaking, L'Arte Vetraria, he wrote, "I have described every last detail clearly and distinctly in this work, I am sure that if you do not purposely foul up, it will be impossible to fail, after having acquired experience and practice." Even in Neri's more obscure works, he earned the respect of later chemists; in 1870, in the journal Nature, George Rodwell, the first science master of Marlborough College, pronouncing him a "sensible chemist." Rodwell went on to note that Neri had used "no less than thirty-five different names, and twenty-two symbols" to denote a single material, the metal mercury. 

In still other writings, it becomes clear that Neri was deeply concerned that some alchemical operations were inappropriate for general consumption and were better kept secret among true practitioners of the art. In particular, he worried that if the transmutation of base metals into gold and silver were practiced widely, the result would be a collapse of the economy and would ultimately plunge civilization into disarray.

We will start with his glass book, where his materials and methods are detailed with special consideration for those not familiar with the art. Then perhaps we can build on that and make sense of his more esoteric material.

In L'Arte Vetraria, Neri gives four different methods to make crocus Martis. He explains: 

Crocus Martis is nothing other that a refinement and calcination of iron. A means by which its pigment, that in glass is a deep rutty red, is opened and imparted to the glass. It not only manifests itself but makes all the other metallic colors as well, which ordinarily hide and are dead in the glass, dance in resplendent apparition. Since this is the way to make the hidden metallic colors appear, I have put down four ways to make it.

The term calcination means only 'to roast' in a hot oven. It derives from the ancient practice of cooking seashells into powdered quicklime, which is a prime ingredient of cement; now called calcium oxide.  In his first method for crocus Martis, Neri mixes iron filings with sulfur and then heats the mixture in the furnace for a long period. We can guess that the result is a mix of iron oxide and iron sulfide. These are the constituents of a popular red pigment of the same name (Crocus Martis) used in pottery glazes. In the second method, he takes the iron and sulfur mixture and sprinkles it with vinegar and leaves it in the sun for many days. The third method uses aqua fortis (nitric acid) for better effect. In the fourth and final method, Neri uses aqua regis, an even stronger acid. 

In all four cases the predominant result will be for the acids to chemically react with the metal to form iron oxide and sulfide, but alas, chemistry is not that simple; there will be minor concentrations of other compounds depending on the acid used, which may or may not affect the final product. We must consider that vinegar and the other acids in the seventeenth century were significantly different from those products today. They were made by different methods and contained a variety of impurities that would never be found in the current products. As Neri notes, each method produces different effects in the glass and therefore we must conclude that each, to some extent, differs in chemistry as well. Today, we know that iron forms several different oxides, each responsible for different color effects in glass. In a number of green glass recipes Neri uses crocus made with vinegar, yet in chapter 71 he uses it to diminish the green in yellow lead crystal. In chapter 124 he uses crocus made with aqua fortis for red glass. The lesson here is that the name of a material tells us only the basics, how it was made is at least as important if not more so. 

* this post first appeared in a somewhat different form on 15 August 2014. 

Vitriol of Venus

 

Crystals of Copper Sulfate Pentahydrate

(Vitriol of Venus)

Vitriol of Venus was one of the most cherished items in Antonio Neri’s chemical library. In his book, L'Arte Vetraria, he describes its effect in glass this way:

To your great contentment, you will be astonished at what you see. I do not know of anybody else who has tried it this way and I Priest Antonio Neri trying it found it most marvelous, as said above, and it is of my own invention. [1]

To be clear, Neri is claiming a novel preparation technique for a chemical substance that was known since antiquity. I think it is quite reasonable to say that a particular personality trait led him down this path of discovery; his almost maniacal drive for purification. For a seventeenth century alchemist, it is a trait that served him well. Where other practitioners were content to use contaminated or substitute ingredients in their formulations, Neri always goes the extra mile in verifying his ingredients and using any extra filtering steps that might be warranted, no matter how time consuming. More than anything else this is what led him to such success in glass formulation, the assurance of exceptionally clear product and bright colors.

He is so proud of his creation that he spreads the description of his method over four full chapters of the book, going into a level of meticulous detail that is extreme, even for Neri. Rest assured, dear readers, that I have taken the liberty of distilling said description down to a more manageable form for your reading pleasure. Nevertheless, our priest-alchemist clearly puts great stock in this preparation, going so far as to drop hints that this material has uses that go far beyond glassmaking: "Many things could be said here, which are omitted as not being pertinent to the art of glassmaking, which perhaps upon another occasion you will be able to judge." [2]

Before starting, he gives some general advice:

You should make the sulfurs, vitriols, ammoniac salts, and similar materials slowly, over a low fire, so they are well prepared and well opened, because a violent fire will cause great damage to them.[3]

To begin, Neri cuts thin copper sheet into small pieces half the size of a small coin. filling a crucible, he layers the copper pieces with common sulfur (known as brimstone).  He cements the vessel shut with a lid and then buries it in the hot coals of a drafted furnace for two hours.

The dark purple contents are then ground and sifted through a fine screen, mixed with six ounces of pulverized sulfur per pound and then heated in a round terracotta pan, which is sitting in the hot coals. When the sulfur starts to burn, he stirs the mixture, rolling it into balls with an iron hook so it does not stick to the pan, continuing until it stops smoking. He removes the mixture from the heat, grinds it finely, adds more sulfur and repeats the entire process three times.

Neri grinds the resulting reddish tawny colored material into powder, putting a pound of it into a large glass vessel containing six pounds of clean water and gently evaporate away a third of the water. The liquid is carefully poured off and saved. The residual solids are dried and recycled in the process. Now more solids are allowed to settle out of the "beautiful blue" liquid over a two-day period and then the liquid is filtered through a felt cone.

He heats the liquid again, this time evaporating two thirds and then puts the remaining third into glazed terracotta pans, and leaves them in a cold damp place overnight. "You will find the vitriol of copper has formed into crystalline points that mimic true oriental emeralds." The crystals are removed, dried and the liquid is further evaporated in order to obtain more crystals. To the chemist, this material is copper sulfate pentahydrate [4]; today it is sold inexpensively as a fungicide for swimming pools. One reason it was so valuable to alchemists is that when gently heated or added to water this chemical forms a sulfuric acid solution. 

This is the true flaming azure blue [tincture], with which marvelous things are made. It is most potent, and as sharp as anything known in nature today, as can easily be perceived from its odor.

However important this was in other areas of alchemy, those applications do not have any particular relevance to the blue-green tint it imparts to glass, which he does make use of throughout the book. The full recipe was so long that he continued it several times and finished as the final chapter of L'Arte Vetraria. Here are the closing words to the book:

Although I have placed here the way to make this powder with much clarity, do not presuppose that I have described a way to make something ordinary, but rather a true treasure of nature, and this for the delight of kind and curious spirits.[5]

[1] Neri 1612, ch. 31.
[2] Ibid, ch. 133.
[3] Ibid, ch. 37.
[4] CuSO4•5H2O

[5] Ibid, ch 133.
* This post first appeared here on 29 Aug 2014.

Casino di San Marco

 

The Casino di San Marco, Florence
Location of Antonio Neri's first glassmaking job

In 1612, Antonio Neri wrote the first book entirely devoted to making glass from raw materials. It was called L’Arte Vetraria, or in English, 'The Art of Glassmaking'. When Neri put pen to paper for his book, he had already been making glass for over a decade. He had the opportunity to learn his craft from some of the experts in the field. At the beginning, his first known experience in glassmaking was at the laboratory palace of Don Antonio de’ Medici, a prince from the ruling family of Tuscany. 

The Palace was called the Casino di San Marco. “Casino”, we might innocently guess indicated some kind of gambling hall, which it was not.  Instead, "Casino" was Italian parlance for a palace that was informally organized like a small country house with the living quarters on the ground floor. It was built by Don Antonio’s father, the former Grand Duke, as a place where Nature’s secrets would be discovered and new inventions would be made. Neri worked at the Casino for a couple of years before moving to Pisa and then to Antwerp, all the while making glass. He returned to Florence to publish his book, in which he thanked Don Antonio for his long patronage. 

Don Antonio's Casino was as much a grand concept as it was a physical space. Completed to his father’s specifications in 1574, it evolved into a prince's palace par excellence. Within its walls, grand dinners were held, productions were staged and poetry was read. In 1605 Michelangelo Buonarroti the younger staged a play there titled "The Christmas of Hercules." In its chambers, music was performed, philosophy debated and diplomacy conducted. In its laboratories, alchemy was nurtured, and glass was formulated. It was a sort of grand royal conservatory, melding together art, letters, drama, music and science. From its courtyard, hunters set forth into the Tuscan hills in search of unicorns, and within its workshops, artisans explored the territory of new materials and natural secrets.

The Royal Foundry, as it was also called, became a place of pride for Grand Duke Ferdinando. It was a place that visiting dignitaries specifically asked to see and tour. Behind the doors of the Casino di San Marco, Antonio Neri and his associates worked their magic. This is probably where he first learned the secrets of Venetian style glass composition and undoubtedly much more. He assisted the prince in his research, formulated herbal remedies and helped in the production of luxury gifts for visiting dignitaries.

This was the way that I made chalcedony in the year 1601, in Florence at the Casino, in the glass furnace there. At that time, the task of scheduling furnace-work fell to the outstanding Mr. Niccolò Landi, my close friend and a man of rare talent in enamel work at the oil lamp. I made many pots of chalcedony in the furnace there. I never deviated from the method stated above, I always prepared the materials well and it always came out beautifully in all my proofs.[1] 

[1] L'Arte Vetraria, Antonio Neri 1612, p. 41.

* This post first appeared here in a shorter form on 12 August 2012.

Caterine Sforza

 

Caterina Sforza, by Lorenzo di Credi

(now in the Museum of Forlì.)

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

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

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

Her chemical recipes were transcribed in 1525 by a captain in her son's army, Count Lucantonio Cuppano da Montefalco, and ultimately published as a book in 1893 (Pasolini). Included are an assortment of formulas which range from cosmetics, to medical remedies, poisons and alchemical concoctions.
Researcher Jacqueline Spicer writes:

Lost among the romanticized military conquests is a thorough account [of] the project that occupied several years of her life—the manuscript of her alchemical and medical experiments and recipes titled Gli Experimenti de la Ex.ma S.r Caterina da Furlj Matre de lo inllux.mo S.r Giouanni de Medici, or Gli Experimenti. The text is an early example of what would later become the popular medical genre of "Books of Secrets", but is so early that it does not appear in most modern writing on such books. Furthermore, Gli Experimenti is unusual because it was written by a woman in an otherwise male dominated genre, and unique in that we know a great deal about the life of its author.[1]

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

Sandro Botticelli, Primavera (1498)
(detail - rightmost of the three graces)

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

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

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

Sarah Worral Grazebrook

 

Guest Post

Conciatore is very pleased to present a guest post by Dr. Kate Round in which she acquaints us with the owner operator of the Audnam Glassworks in the mid 1700s.

Sarah Worral Grazebrook 1721-99
by Kate Round

After reading of Sara Vincx who in 1595, following the death of her husband, ran a successful glassmaking business in the City of Antwerp; I was reminded of a local successful businesswoman running a Glasshouse in Audnam, near Amblecote in Stourbridge, when the glass industry was flourishing in the 18th century.

Glassmaking was established in Amblecote after Lorrainer glassmakers arrived in the early 17th century. They were attracted by the best fire clay, cheap coal, sand and soda made from the burnt bracken on Pensnett Chase. De Houx built one of the early glasshouses in 1618 in Amblecote and glasshouses eventually spread over the parish making many and varied products.

Audnam Glasshouse was built in 1716 and was run by Henry Bradley. His business suffered due to the decline in the price paid for broad glass coupled with the introduction of the glass tax in 1745. He finally surrendered his business in 1747 to his landlord, Baron John Ward of Dudley.

Map of Stourbridge area canal system incl.

Audnam Glassworks cone,

1774 map by Robert Whitworth.

(Click to enlarge map.)

Baron Ward immediately let the glasshouse to Michael Grazebrook I at an annual rent of £50. The association between the Dudley family and the Grazebrooks lasted 112years. Business flourished and his son Michael II (born 21st June 1723) learned the trade.


Michael II married Sarah Worral on 16th January 1753, Michael was 29yrs old and Sarah who was an only child and an heiress of Stourton in Staffordshire was aged 31. It was not uncommon for eligible businessman to seek a bride who would bring further prosperity to their allegiance. In 1640 Paul Tyzack, one of the original Huguenot glassmakers to settle in the area was sufficiently integrated into local society to see his son Paul II, marry Joyce Lyddiatt the daughter of his landlord, John Lyddiatt a scythesmith of Wollaston Hall. Joshua Henzey son of Huguenot Ananias Henzey, arrived in Stourbridge in 1618 aged just 22years, he wasted no time in marrying Joan Brettle a spinster from a substantial landowning family. Just six days after their marriage Joan gave birth to their son Ananias, baptised in Kingswinford on 5th October 1618.

The marriage between Michael Grazebrook II and Sarah Worral lasted just 15 years. Michael died in 1766 aged 42years. They had two sons, Thomas Worral Grazebrook (11/08/1756) and Michael Grazebrook III (7/03/1758). In Michael II’s will he was described as a master glassmaker and desired that trade be carried on by his widow Sarah and that stock in trade, book debts, personal estate and effects be equally divided between his only two sons, Thomas and Michael III aged 10years and 8years at the time of their fathers death.

In 1760 Audnam Flint Glasshouse was listed as manufacturing Smooth Enamel Glass, Best and Ordinary Flint Glass and Phials. Sarah Grazebrook continued to manage her late husband’s glassmaking business for many years and although both of her sons were involved, they also developed other interests in coal and ironmaking.

The glasshouse at Audnam was shown on local maps when the land around it was enclosed in 1777 and the occupier was listed as Mrs Sarah Grazebrook. She was also recorded as running Dob Hill Glasshouse owned by Robert Honeybourne. Benjamin Richardson who we consider to be the patriarch of Stourbridge glass, wrote in his notebook in 1886 that Grazebrooks needed Dob Hill Glassworks to make bottles; worked by Madame Grazebrook they used to take the material from the glasshouse at Audnam to Dob Hill Glassworks, and vice-versa. It was reported that the glasshouse at Dob Hill ‘fell-down’ sometime around 1800 and a new canal-side glasshouse was built as a replacement.

In 1783 Sarah was listed as a Glass manufacturer in a local directory and in that year also she took out a further 21-year lease from the landlord Lord Dudley. Her lease was in the sum of £52 per annum with maintenance and repairs to be undertaken by the lessee at her own cost. Sarah also took out an insurance policy in both her and her sons names on 5 May 1783. In 1793 a local directory stated that about ten glasshouses in the district had an output so great that they each paid £20,000 per annum in duty (equivalent to £2.8m today). T&M Grazebrook was one of those listed.

Michael III married in 1785 and moved to the family home Audnam House attached to the glassworks. After his marriage both Michael and his brother Thomas took over the running of the business from their mother Sarah. Their business continued to prosper in glass, coal and as ironmasters; the eight-pot glassmaking furnace traded as T & M Grazebrook, yet in 1795 it was Sarah who paid the £53 rent to Lord Dudley. Their mother remained the head of the firm until she died in 1799 aged 78y. Her will divided her estate between her two sons Thomas and Michael III.

For nineteen years, between the death of her husband in 1766 and when her sons were registered as the business owners in 1785, Sarah maintained the business. She was solely responsible for the day to day running of the eight-pot Audnam furnace and a bottle making furnace at Dob Hill. She managed the workforce, maintained healthy order books, purchased raw materials and supplied quality products; thus ensuring a flourishing business to pass on to her sons. Tradition tells that as an old lady Sarah would sit in her bedroom window with an hourglass to time her workmen’s shifts.

Like Sara Vincx in Antwerp in 1595, running successful glassmaking businesses in a male dominated environment must have bought many challenges that went unrecorded. Did Sara marry Filippo Gridolfi, one of her foremen of the furnace, to validate her position. Did both formidable ladies contribute also to product design, were they hands-on with blowing irons despite the taboo of women working glass? Who knows! some things perhaps were best left unsaid?

References:
Buckley, Francis; Old English Glasshouses, Society of Glass Technology 2006

Ellis, Jason; Glassmakers of Stourbridge and Dudley 1612-2002, Xlibris Corporation, 2002

Guttery, D R; From Broad Glass to Cut Crystal, Leonard Hill Ltd, London 1956

Engle, Paul; Sara Vincx, Glass Maker. Conciatore Blog 2013

Dr Kate Round is an outreach presenter and tour guide for Dudley Museum Service, based at the iconic Red House Glass Cone in Wordsley; the home of Stuart Crystal.

In her previous life, she was a research chemist and lecturer so understands the chemistry of glass having worked on the synthesis of ‘zeolites’ (silica-based materials) with her work published in International Journals. "I have always lived in the Black Country and have a strong industrial family heritage; I am also proud to have served my community as a local Magistrate for the past nineteen years. In the glass industry, my areas of interest include the historical development of the industry in the Stourbridge district, how the geology and geography impacted on the wealth and sociology of the area, driven by the rivalry of our Glass Dynasties."


Dr Kate Round JP, PhD, MRSC CChem, BSc(Hons)

Kateround.round@gmail.com

Twitter: @RoundKate

Alchemy School

 

Frontispiece woodcut from

 De Chemia Senioris, by Zadith ben Hamuel, 1566

A common notion holds that alchemists were eccentrics, lone practitioners working in dingy basements, cut off from the rest of the world. This was a myth already well established in glassmaker Antonio Neri's time, but far from the whole truth. In the early seventeenth century, alchemy was practiced in medicine and pharmacy, in precious metals refining and even in the preparation of artists' supplies. The glassmaker was in good company. Where Antonio Neri received his training is unknown, but there are intriguing clues. 

We turn first to Antonio's own father, Neri Neri, the royal physician to the Medici family. According to historian Giulio Negri, he received his medical degree at the prestigious Studio Fiorentino, the forerunner of today's University of Florence. At the time, it had already been in operation for two centuries, having been granted a charter in 1348 by Holy Roman Emperor Charles IV. The charter was a response to a personal appeal by Archbishop Piero Corsini. Antonio Neri's own distant relative, Ser Giovanni Neri, later became Corsini's secretary, so a family legacy of attendance is not out of the question. That our priest might attend his father's alma mater is pure speculation, but it seems foolish to doubt that he started his alchemy education at his father's knee, in his own home.

The manuscript entitled Treasure of the World that Antonio devoted to "all of alchemy" was completed in 1600, but started two years earlier. On a page near the beginning, dated 1598, the twenty-two year-old clearly identifies himself as a "priest." Church rules forbade anyone from becoming a novice before the age of sixteen, which for Neri would have been in the spring of 1592. Full ordination as a Catholic priest typically took six years, meaning in 1598 Neri only recently underwent the 'laying on of hands' ceremony by the archbishop, confirming his title. The inescapable conclusion is that Neri learned his craft while in seminary and the Church sponsored his education. 

The identity of Neri’s order is a mystery, but the few scattered pieces of the puzzle that we do have allow for some interesting speculation. The list of candidates having some connection to the priest and the means to support, if not supply an education is not long. The five names that stand out are the Dominicans, the Carmelites, the Augustinians, the Knights of Malta and the Benedictines. The Dominicans were noted for their scholarship and ran two apothecaries in Florence. The Carmelites are named in the deposition notes taken by Agnolo della Casa, which identify Neri’s confessor as such. The Augustinians counted a Francesco Neri as abbot of their San Clemente monastery who worked for Don Antonio de’ Medici at the Casino in 1619. Antonio’s aunt, Faustina, apparently entered an Augustinian convent after the death of her husband.  Also, though Neri’s confessor was a Carmelite, he also served as the parish priest of an abbey run by the Canons Regular of the Lateran—an independent Augustinian congregation. The Knights of Malta ran two churches in Florence and Neri can be connected to both.  The knights followed the rule of Augustine and enjoyed a close relationship with the Augustinians. The order traces its roots to the crusades  and has various associations with alchemy such as George Ripley. Their main presence was on Malta, though in 1565 they suffered a devastating defeat there to the Ottomans. Neri was not a knight, but he could have occupied a place in their clergy. In Florence, any resources for schooling in alchemy by the knights would have been overseen by its most prominent local official; that official was Neri’s benefactor Don Antonio de’ Medici, Grand Prior of Pisa. The Benedictines were also associated with Neri’s family and had the means to provide him with an education in alchemy. He was born in the parish district of Benedictine church, San Pier Maggiore. His father was buried in the Cistercian (reformed Benedictine) church of Cestello. His sister  committed to a Benedictine order (the Camaldolese). After his ordination, in 1601, Priest Antonio Neri lived across the street from the Vallombrosan (Benedictine) mother church, Santa Trinita.

In any case, as royal physician Neri's father was an esteemed member of the court and Antonio would have enjoyed rare access to its inner sanctum. The grand duke's own laboratory at the Galleria dei Lavori certainly would have been a familiar haunt for our alchemist-priest.

This post first appeared here in a shorter form on 2 October, 2013.