Neri in Pisa

Majolica vase by Niccolò Sisti,

decorated in the grotesque style.

Antonio Neri's career in glassmaking took him from the city of his birth, Florence, to Pisa, Antwerp and possibly other places yet to be confirmed, such as Rome and Venice. Under the reign of Grand Duke Ferdinando de' Medici, a glass furnace at Pisa became an important source of diplomatic gifts in both glass and ceramics. Antonio Neri worked at this facility in the first years of the seventeenth century. Later, the same foundry would receive an order for exceptionally clear glass to be used by Galileo in his telescopes. It is unknown how that particular project worked out, but the furnace master, Niccolò Sisti, made a name for himself supplying glassware to the Vatican, the king of Spain and many nobles throughout Italy and Europe. Undoubtedly, Neri's glass career was strongly influenced by his tenure in Pisa with Sisti. 

In the early seventeenth century, there were several glass furnaces in Pisa. One was run at the pleasure of Grand Duke Ferdinando by Niccolò Sisti. Raised in Norcia in Perugia, he likely learned his trade at an early age;  Sisti's father, Sisto de' Bonsisti, was said to be an expert in making paste gems. This would account for the son's apparent skill in the medium of glass in addition to his ceramics prowess for which he was previously employed at the Casino di San Marco in Florence. For Neri, working at Sisti's glass house in Pisa played an important role in his glassmaking education. Sisti would serve three Medici grand dukes, Francesco I, Ferdinando I and Cosimo II. When work came to a stop at the Casino di San Marco, after Francesco’s death, Sisti may have opened his own factory in Florence for a short time, but then moved to a new facility in Pisa.

 In 1592, Grand Duke Ferdinando set up a glass shop in the central part of Pisa, along the north bank of the Arno River. This furnace was staffed by Muranese workers and was located in the city center, along the river. Archaeologists have unearthed its remains in the courtyard of what is now 43-44 Lungarno. The operation was capitalized with a loan of five hundred scudi made by Ferdinando I to Sisti, with a special mandate: he was to introduce new forms of pottery to the region. In addition to glass, the furnace at Pisa would produce soft-paste porcelain and majolica ceramics. These were both forms that Sisti had helped to develop when he worked in Florence at the Casino; he was involved in Francesco’s quest to duplicate Chinese porcelain.

In 1602, Neri was to be found working alongside Sisti at the Pisan furnace. According to his own account, this is where he worked on special colors, and collected river stones for glass frit. Here he made kermes based paints, enamels and used ferns as an alternative plant salt for glass. In all likelihood, he would have had access to the nearby botanical gardens and the small adjacent laboratory located just a few blocks from the glass furnace. 

Early in 1604, the priest would make his trip north to Antwerp to visit his friend Emmanuel Ximenes. During Neri's seven year absence, Sisti's projects included cristallo table service for the Vatican, and special glass for the lenses of Galileo's telescopes. Upon Neri's return from Flanders, we again find him working in Pisa, this time on alchemy. In a copy of his last known manuscript, a heading reads, "Techniques copied from an old book here in Pisa."  The university at Pisa was an intellectual center and a repository of technical knowledge. There, Neri had access to a wide range of materials in the libraries. The furnaces and laboratories provided him with hands-on experience, but there can be little doubt that he was a voracious reader as well. On the same page of this manuscript appears the date 26 January 1614. This is the last known specific information on the priest's whereabouts, since he would be dead within the year, at the age of thirty-eight.

*This post first appeared here in a shorter form on 18 October 2013.

Dear Friends

The library of the University of Leiden (1610)

Christophe Plantin worked here from 1583 to 1585.

One day in July of 1601, in Florence, early in the morning, we imagine two men shaking hands, embracing and saying goodbye. Both knew it might well be the last time they saw each other. The older man climbs into a coach bound for his home in distant Antwerp and signals the driver to begin his journey. That man, Emmanuel Ximenes, had been in Florence to visit his sister, Beatrice, his brother, Niccolò, and several other relatives living in the area. Antonio Neri first met the wealthy banker at the home of Beatrice and her husband, Alamanno Bartolini. The priest lived there after his ordination and, according to nineteenth century historian Francesco Inghirami, functioned as house-master. Both men wished for more time together; they shared a fascination with alchemy and with the work of Swiss-born physician Paracelsus. They had become fast friends and formed a bond that would last until the end of their lives.

As soon as Ximenes arrived home in Flanders he wrote to Neri, on 17 August, 1601, "to the quite magnificent clergyman Mr.Antonio Neri, in the house of Mr. Alamanno Bartolini, in Florence, or where found." He expressed his great pleasure at receiving a booklet of recipes from Neri and declares him "molto caro" [most dear]. He goes on to warn his friend: "With your permission, I will not fail to bother you with my tiresome letters." Over the next two years, the men corresponded frequently. A set of twenty-seven letters written by Ximenes and one by his brother Eduardo, addressed to Neri, survive in the National Library of Florence. The two men discuss a wide variety of subjects including herbal remedies, glassmaking, enameling and in more careful language, the topic for which they were both most passionate: alchemy. They trade information on the results of their experiments and by 5 December, 1602, the banker wrote:

I have seen the tender affection which Your Lordship shows me and demonstrates with the hope to see me before death, which is no different from my own hope. I have desired this from the start… because if we were together, we could easily set to work on some small projects, being that our talents, if I am not deceiving myself, are very well suited...

Neri would ultimately make the journey to Antwerp, but not for another year. That winter he became quite ill in Pisa, postponing his planned visit. Finally, on 2 May, his friend wrote: "Praise God that your indisposition has ended." By the following spring the two men were reunited and Neri would spend the next seven years in a city that was in the eye of a storm. The low-countries (what today are the Netherlands and Belgium) were in the midst of a bloody civil war. The port of Antwerp was blockaded by the Dutch fleet and the countryside was being ravaged by troops from Spain and the Holy Roman Empire. The population of Antwerp was a shadow of its former self, but the city was left untouched by both sides, in an accord of political convenience. It had been burned and pillaged as recently as the 1570's, but by the early 1600's Antwerp was simply too valuable a jewel to be sacrificed.

Emmanuel's immediate family was among the wealthiest in Antwerp and strong patrons of the arts. He counted among his close friends humanist printers Christophe Plantin and Jan Moretus. Other branches of the Ximenes family topped the social ranks in Venice, Hamburg, Lisbon and Florence. Their ancient ancestors were kings of Pamplona, Navarre, Castile and Aragon. Emmanuel's father Rodrigo headed the prestigious Ximenes (Jiménez) Bank in Antwerp. By the end of his visit, Neri would present the prince of Orange with vessels of his chalcedony glass.

This post was first published here, on 6 September 2013.
For more on Ximenes, see http://ximenez.unibe.ch/

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 transcript 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.

Artificial Gems

Pastes (glass) set in silver openwork (Portugal c. 1750)

Victoria and Albert Museum, London.

Acq. nr. M.68-1962

In many ways, the story of artificial gems traces the story of glass technology itself. From ancient times, when glass could only be produced in very small quantities it was regarded and used as a type of stone that was made through art. Alchemists thought the bright colors produced by metallic pigments in glass were a key to the philosopher's stone, and the transmutation of base metals into gold. As the technical prowess of glassmakers expanded, so did the ability to simulate specific stones, most notably coveted gems. Glass went on to be used as material for utilitarian objects like goblets and as an indispensable part of scientific enquiry. All the while, artificial gems have continued to dazzle us with their beauty. 

In the fifth part of Antonio Neri's 1612 book, he teaches the secrets of making artificial gems "of so much grace, and beauty, that they will surpass the natural stones in everything except hardness." It is not a difficult argument to make that this section alone is responsible for much of the lasting popularity of L'Arte Vetraria. It is easy to see why enterprising artisans would want to make glass imitations that could pass for the real thing. It is also perhaps too tempting to jump to the conclusion that Neri intended his recipes to be used in deception, since there is no evidence whatsoever that this was the case.

Neri gives full credit for his innovative methods in paste gems to Dutch alchemist Isaac Hollandus. Hollandus is an enigmatic figure, whose writings survive, but not much is known of the man, his family, or even if he was living in Neri's time. What is known is that Antonio's dear friend Emmanuel Ximenes was the brother-in-law to Baron Simon Rodriguez d'Evora, a famous diamond dealer and jeweler of choice to royalty throughout Europe. He lived and worked on the same street in Antwerp as Ximenes' palace, only a few steps away from Neri's new temporary home. It was a common request of wealthy patrons to have duplicate jewelry made in paste for travel and security reasons. If a fake necklace or jewel could pass for the real thing, it was well worth the added expense, when the genuine article could remain safe under lock and key.

No artificial gem recipes have ever been found among Hollandus' writings, excepting one for ruby which is then crushed up as part of a prescription for the philosopher's stone. It is quite possible that Neri was applying a more general technique from the Dutchman. The basic material for all of Neri's paste gems is a fine lead crystal. The crux of his innovation lay in the form of lead used. Normally, metallic lead sheet was cut into small pieces, and roasted in a kiln such that it would oxidize into powder, but not melt. The powder was then added to the glass melt. In Neri's method the lead was chemically converted into a water-soluble form, which could then be filtered and purified to a much greater extent. The end result was a far better grade of crystal.


In 1697, Jean Haudicquer de Blancourt translated into French and greatly expanded Christopher Merrett's English edition of Neri. Blancourt gave no credit to the Italian for his work, and two years later, when it was translated back into English by Daniel Brown, the connection to Neri was completely lost, but the credit for paste gems remained with Hollandus. In the eighteenth and nineteenth centuries, numerous general encyclopedias of art and craft were published and the so-called 'Hollandus' paste gem recipes turned up many times. Meanwhile, a properly credited French version of L'Arte Vetraria was completed by Holbach in 1752. This edition was more suited to a scientific audience; he faithfully translated the Italian, but also incorporated the full comments of Merrett as well as those of Kunckel who issued his famous German version of Neri in 1679.

For more reading on Neri's artificial gems see Glass as Pasta and on the work of later investigators see Marieke Hendriksen at The Medicine Chest
*A shorter version of this post appeared here on 16 September 2013.

Scraping the Barrel

4th century BCE philosopher Diogenes

(supposedly lived in a wine barrel)

by Gaetano Gandolfi (1792)

To seventeenth century glassmaker Antonio Neri, "tartar" was a well-known byproduct of the winemaking process. If we chill wine or grape juice to below 50 degrees (10 deg. C.) crystals of tartar start to form and once they do, then tend not to dissolve back, even at room temperatures. Today, these crystals are commonly found in a powdered form, in kitchen cupboards as "cream of tartar." Bakers and cooks use it to stabilize whipped egg whites, and it has a number of other applications. 

Neri used tartar in his glass to add sparkle, a trick known to Venetian glassmakers as early as the 1400s. It was obtained from the dregs at the bottom of wine barrels. To understand how this works, it is useful to know that Florentines, Venetians and most southern Europeans made glass from crushed up quartz pebbles or sand mixed with a specific flux known as "glass salt." This salt was rich in sodium carbonates, which greatly reduced the melting point of the quartz. It allowed artisans to work the material at the temperatures easily achieved in their furnaces. Tartar turns out to be very similar, except that it is rich in potassium rather than sodium. 

Potassium atoms are larger and heavier than sodium atoms and when light passes through a piece of potassium-fluxed glass, it bends and refracts more. This effect is not as pronounced as when adding the even heavier lead to form fine crystal, but it still adds noticeable sparkle to finished pieces. Using all tartar as a flux has the undesirable effect of reducing the workability of the hot glass. Outside the furnace, it becomes stiff quicker and artists have less time to create fancy shapes and forms. The solution to this dilemma is to use a mix of sodium and potassium fluxes together, which is exactly what Neri did. 

In his 1612 book L'Arte Vetraria, he shows how to prepare tartar and then adds it to a number of his glass recipes saying, "The tartar is the secret way to produce more salt and to make cristallo which is whiter and of rare beauty." Here is Neri’s prescription:

To make Purified Tartar Salt you should obtain tartar, which is also called gruma, from barrels of red wine in which it forms large lumps, however do not use powder. Roast it in earthenware pots amongst hot coals until it becomes calcined black and all its sliminess is roasted away. It then will begin to whiten, but do not let it become white, because if you do the salt will be no good.  

Calcine tartar this way: put it in large earthenware pans full of hot common water, or better yet in glazed earthenware pans then made to boil on a slow fire. You should do it in such a way that in two hours the level of the water will slowly decrease to one-quarter, at this point lift it from the fire and leave it to cool and to clarify. Now decant off the liquid, which will be strong lye and refill the pans containing the remains of the tartar with new common water. In the way stated above, boil as before and repeat the procedure until saltiness no longer charges the water. 

At this point, the [decanted] water is impregnated with all the salt. Filter the lye clear and put it in glass chamber pots to evaporate in the ash of the stove over a slow fire. In the bottom, white salt will remain. Dissolve this salt in new hot common water and leave it in the pans, letting it settle for two days. Then filter it and return it to chamber pots to evaporate over a slow fire. In the bottom, a much whiter salt will be left than the previous time. Now dissolve this salt in fresh hot common water and leave it to settle for two days. Evaporate, filter and repeat everything as before. Overall, repeat this procedure four times to dissolve, filter and evaporate the salt of tartar. This will make the salt whiter than snow and purified from the vast majority of its sediment.

When mixed with sifted polverino, or rocchetta, with its doses of tarso [quartz] or sand, this salt will make a frit that in crucibles will produce the most beautiful crystallino and common glass, which one cannot make without the accompaniment of tartar salt. Without it [tartar], good fine crystallino can be made, nevertheless with it, it will be the absolute most beautiful.

*This post first appeared here on 16 May 2014.

Pebbles from Pavia

A Bridge on the River Ticino, near Polleggio,

William Pars (1742‑1782).

In the sixteenth and seventeenth century, a type of glass known as 'cristallo' was the absolute pinnacle of the art. Its recipe was invented in Venice and guarded there as a state secret. Its name derived from the mineral it was designed to mimic: rock crystal. As clear as water, rock crystal was valued since ancient times for carving into cups, vessels and other objects of art. Today we know it as a form of quartz, but in Roman times it was thought to be a type of frozen or coagulated water.

In the early 1600s, when Antonio Neri started making glass in Florence, the grand duke's craftsmen were routinely carving this hard and brittle rock crystal into complex thin shapes, a process that took great skill and effort. Due to the expense involved in producing a piece, this art was the exclusive province of extremely wealthy individuals. Thus, objects made from rock crystal were considered markers of status. The recipe for cristallo glass was a very great secret indeed, but its real value lay in the specific materials used. Even if the recipe found its way out of Murano, which it inevitably did, the Venetian's tight trade network ensured a monopoly on many of the ingredients. It is said that even the furnace crucibles for cristallo were made from a specific clay gathered in Constantinople.

Cristallo was not only exceptionally clear, but for the artist it had working properties like no other glass. Thin, complex shapes were possible in cristallo that could never be duplicated in common glass. The secret for making cristallo came to Florence in the late 1560's, only a few years before the birth of Antonio Neri, who would learn the techniques and go on to publish the recipe for the first time anywhere.

 After protracted overtures, which involved diplomats, spies and the archbishop of Florence, Grand Duke Cosimo I managed to negotiate with the Venetian Doge and Senate for a Muranese master and two assistants to come to Florence and teach the way to make cristallo. It is likely that the raw materials were all purchased through the Venetians, at least initially. By the time Neri wrote his book, L'Arte Vetraria, in 1612, the Florentines were already finding alternate sources. In Venice, the ingredients of cristallo were prescribed and controlled by strict laws. The Florentines did not have this constraint and were free to experiment.

In the second recipe of Neri's book, he spills the beans on where the Venetians procured the single most important ingredient for cristallo, the pure quartz stones which account for the material's clarity. Notice in the following excerpt that Neri mistakenly thinks that the white river stones are a form of marble and also notice the alchemical language he uses to describe the process in which the stone is "transmuted" into glass.

When you want to a make cristallo that is beautiful and fully perfect, see that you have the very whitest tarso. At Murano they use pebbles from Ticino [Pavia], a stone abundant in the Ticino River. Tarso, then is a species of very white hard marble [quartz]. 

In Tuscany, it is found at the foot of Mount Veruca in Pisa, at Seravezza, at Massa near Carrara, and in the Arno River both above and below Florence. In other places as well, common stone is often recognized, which is seen to have the same qualities as tarso; it is very white and does not have dark veins, or the yellowish appearance of rust, but is spotless and pure. Take note that any stones that will spark with a piece of steel or strike plate, are apt to vitrify and will make glass and cristallo. All those stones that do not make sparks with a piece of steel or striker as above will never vitrify. This serves as advice for being able to distinguish stones that have the ability to transmute their form, from those that cannot be transmuted. 

Start with this same tarso, as fair and as white as possible. Grind it finely into powder in stone mortars. Do not use bronze or any other metal for this purpose or the stone will take in the color of the metal, which then would tinge the glass or cristallo, and make it imperfect. The pestle must be iron by necessity but at least the other materials will not have the possibility of causing any effect. Pulverize the tarso well and sift with a fine sieve. It is important that the tarso is ground as finely as flour, so that it will all pass through a fine sieve.

* This post first appeared here on 30 May 2014. 

The Glass of Montpellier

Montpellier, France, in the seventeenth century.

(Attribution unknown)

Montpellier is an old city in southern France. It stands about halfway between Marseille and the Spanish border along the Mediterranean Sea (strategically located slightly inland to avoid pirates). First documented in the tenth century, it is one of very few French cities that developed without the influence of ancient Roman occupation; it is a pure product of the local region. It became a center of intellectual learning and attracted students from throughout Europe. Around it sprung a number of supporting arts not the least of which was glassmaking. Once famous for its fine glassware, today this centuries long heritage is all but forgotten, yet when we dig into the literature, we find a surprise connection to one of the oldest legends in the history of glass.

Since before the Renaissance, Montpellier was an established center for medical and legal education, a strong tradition that continues at the university there; today, it houses the oldest running medical school in the world. This prestigious institution "was founded perhaps by people trained in the Spanish medical schools; it is certain that, as early as 1137, there were excellent physicians at Montpellier University." [1] In 1529, Nostradamus entered to study for a doctorate in medicine, but shortly thereafter, he was expelled when it was discovered that he previously worked as an apothecary; a 'manual' skill that was banned by the school's rules of conduct.

Paradoxically, these impugned 'manual' arts account for some the region's more intriguing activity. Along with medicine, the area became known for the production of paint pigments, for glassmaking and finally for alchemy. All of these turn out to be closely related to each other, but perhaps not obviously so. Throughout the Renaissance, apothecaries were responsible for a wide range of distillations and extracts used by physicians to treat disease. They were also the de facto suppliers of pigments and other fine art supplies and even sourced some of the materials for glassmaking. Glassmakers often relied on painters to embellish their products, painters used ground glass in their pigments and apothecaries needed glassmakers to produce the flasks, beakers and other alchemical equipment required for their profession.

An anonymous Montpellier manuscript of the fourteenth century, called the Liber diversarum arcium [Book of Various Arts], offers us one of the most complete guides to the production of pigments to have survived from that period. [2] Another, later writing of the sixteenth century offers an extensive collection of glassmaking recipies brought to Montpellier from Venice. This one is titled Recette per fare vetri colorati et smalti d’ogni sorte havute in Murano 1536 [Recipes to make colored glasses and enamels of every kind as in Murano, 1536]. [3]

Local history points to the town of Claret just north of Montpellier as the seat of regional glassmaking. Beginning in 1290, the oak forests on the Causse de l'Orthus attracted glassmakers and their families. "So maybe the oaks got used for fuel. (A 'causse' is a geological term for a limestone plateau.) [also a material of glassmaking] At any rate, the glassmakers were ennobled by the King and formed a guild of premium glassmakers whose wares were sold all over Europe from the market at Sommières." [4]

In the early seventeenth century, Pierre-Jean Fabre (1588-1658) studied medicine at Montpellier where he discovered the works of Paracelsus, to which he became a devotee. [5] After securing a medical degree, he returned to the nearby town of his birth, Castelnaudary, to work as a doctor. Eventually, he was awarded the status of "Royal Physician" by Louis XIII, probably for his work on treating victims of the plague with chemical preparations. [6]

Fabre's first book, of a total canon numbering sixteen volumes, was on the subject of alchemy and medicine titled "Palladium spagyricum" 1624. [7] The book, written in Latin, contains advice on the transmutation of metals, turning water into "good wine" and elixirs to cure all disease. It contains one recipe that is of particular interest on the subject of glassmaking; a malleable form of glass, known in legend since the Roman Empire as Vitrum Flexile.

See my previous post to take a closer look at Fabre's specific recipe for a glass that is malleable at room temperature and trace a bit of the legend's history.

[1] Wikipedia, “University of Montpellier” https://en.wikipedia.org/wiki/University_of_Montpellier.

[2] Mark Clarke: Mediaeval Painters' Materials and Techniques: The Montpellier Liber diversarum arcium (London: Archetype Publications, 2011).

[3] Montpellier 1536, MS. H. 486: Recette per fare vetri colorati et smalti d’ogni sorte havute in Murano 1536, Bibliothèque de l'Ecole de Médecine de Montpellier, see also Zecchin 1987, v.1 p 247-276. Although the manuscript is dated 1536 it is probably copied from much earlier Venetian sources.

 [4] Ed Ward, Blog: City on a Hill, 1 Nov. 2010 post “Where the Glass-Blowers Were.” http://wardinfrance.blogspot.com/2010/11/where-glass-blowers-were.html . Also see Halle du Verre regional glass museum website http://www.cc-grandpicsaintloup.fr/-Halle-du-verre-.html .

[5] Paracelsus (1493-1541) was a Swiss born physician and alchemist who looked to nature rather than ancient texts for remedies to disease. He was widely condemned durring his lifetime but became very popular after his manuscripts were printed in the late sixteenth century.

[6] The definitive reference on Fabre is Bernard Joly: La rationalité de l'alchimie au XVIIe siècle (France: Vrin, 1992), pp. 35-50. A good English treatment can be found in Allen George Debus: The French Paracelsians: The Chemical Challenge to Medical and Scientific Tradition in Early Modern France (Cambridge: Cambridge University Press, 2002) pp, 75, 76.

[7] Pierre-Jean Fabre: Palladium spagyricum Petri Ioannis Fabri doctoris medici Monspeliensis ... (Toulouse: Bosc, 1624), p. 276. Later translated into several English editions, notably by William Salmon: Polygraphice: Or the Arts of Drawing, Engraving, Etching, Limming, Painting … (London: T. Passenger & T. Sawbridge, 1685), pp. 598, 599.