Archiater

Antonio Neri's family arms.

In the late 1580s, approaching the age of fifty, Antonio Neri's father was appointed the personal physician to Grand Duke Ferdinando de' Medici. The son of a barber-surgeon, Neri di Jacopo Neri - or Neri Neri, as he was known - had parlayed a degree in medicine into a successful and prosperous career. His elevation to 'citizen' status, a decade earlier, gave him entree into the world of the patrician elite and his appointment as royal physician secured a place for his young family near the top of the Florentine social hierarchy.

The fact that Neri Neri gained citizenship at the age of forty and did so together with his father shows it was not a legacy, but perhaps their medical prowess that lead to the award. One requirement of citizenship was possession of a domicile within the city. The baptism register lists Antonio and all of his siblings as residents of San Pier Maggiore parish, long before the citizenship grant. However, it is in the 1580s that we see the first reference to Neri Neri's ownership of the palazzo at what is now 27 Borgo Pinti.

Baccio Valori was librarian, keeper of the royal herbal gardens and the godfather of Antonio Neri's older sister Lessandra. In 1587, Valori received a letter from Filippo Sassetti, sent from India. Filippo was a native Florentine, the nephew of Antonio Neri's godmother, Ginevra Sassetti. He attended university in Pisa with Valori and they became lifelong friends. In the letter, he notes that he has collected rare varieties of cinnamon in his travels along the Malibar coast. His intention was to rediscover the species thought to be a powerful cure of disease by the ancients. He planned to send a parcel of seeds of these and other medicinal plants. "If it pleases God, in the coming year, I will send this to you, so that you may see it all, together with our Messer Neri Neri, who graces my memories."

In the autumn of 1587, Grand Duke Francesco I de' Medici and his wife Bianca Cappello both became ill and died during a visit by the grand duke's younger brother Cardinal Ferdinando. Pernicious malaria was to blame and accounts by physicians on the scene described identical symptoms for husband and wife. The thirty-eight-year-old Cardinal Ferdinando relocated to Florence from Rome; he took charge and assumed power as the new grand duke of Tuscany. Shortly after, he appointed Neri Neri as his head physician.

Casino di San Marco

The Canio Mediceo di San Marco, Florence

Don Antonio de' Medici'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.

-Antonio Neri 1612, p. 41.

Bisextile

The day of Antonio's birth was leap year day, 29 February 1576, although his baptistery records indicate 1575. According to the old Tuscan calendar, the New Year would not be celebrated for another month, on 25 March, around the equinox. The Florentine calendar was aligned with the beginning of the planting season; swallows returning from Africa would sweep in the New Year, swirling over the city squares and proclaiming the impending arrival of spring. Soon enough the fragrant air would set farmers busy in the fields.

However, Antonio was born to a Florence still very much in the grip of February. He came into the world on a Thursday evening at 9:25 pm, (recorded as 3 and 5/12 hours past sunset). Of all the days to be born, 29 February was considered among the least auspicious. A dire Northern Italian folk proverb states "An bisesti, o la mama o 'l bambi", predicting that when a child is born on this day, by the end of the year either the infant or its mother will die. Indeed, the Italian word naming the day, bisestile, had become a synonym for misfortune or calamity, as is still the case for the French cognate bissêtre.  Whatever stock the family put into ancient superstitions, happily this prophesy did not come true for Dianora or her fourth child Antonio.

The baptistery record for Antonio Neri reads:

Thursday, 1 March 1575:  Antonio Lodovico was born to Mr. Neri Jacopo and Dianora di Francesco Parenti, residents of San Pier Maggiore parish. The time of birth was 29 February, at 3 hours 25 minutes past sunset. The godparents are Francesco di Girolamo Lenzoni, and Ginevra di Federigo Sassetti.

Laughing In the Fern

Fern ash is high in potassium carbonates. If carefully purified it can make an exceedingly clear glass, rivaling or even surpassing Venetian cristallo. It has the additional advantage of being physically tough, making it ideal for engraving or diamond-point work. On the other hand, once out of the furnace it stiffens quickly, giving it a short 'working life' for the hot glass artisan. This limits designs to simple basic forms. While soda-based glass was the norm for the Mediterranean region, throughout the Middle Ages and into the Renaissance, northern Europeans were more likely to be making potash-based glass. They utilized the potassium rich local trees and plants of the northern forests. In France, fern glass is called verre de fougère. In the considered opinion of some connoisseurs, wine tasted better when sipped from verre de fougère cups, hence the delightful expression 'le vin rit dans la fougère' [wine laughs (sparkles) in the fern].

Since the middle ages, fern glass became part of everyday life in northern Europe. It was familiar enough to find its way into literary verse on matters of the heart. There is a nice reference to fern glass by Geoffrey Chaucer, in The Squires Tale:

But notwithstanding, some said that it was
Wondrous to make fern-ashes into glass,
Since glass is nothing like the ash of fern;
But since long since of this thing men did learn,

Chaucer, in turn, borrowed this reference from an epic twenty-two thousand line French poem from the late thirteenth century, when the technique of making glass from ferns was already ancient.

Waxing Moon

In Chapter 5 of L'Arte Vetraria, Neri shows how to extract salt for glass from fern plants in an evocative recipe. Fern was and still is widely abundant in Tuscany. It presented a ready source material for glassmakers of the region. Neri directs that harvesting of the plants be done in the spring:

Cut this herb from the ground when it is green, between the end of the month of May and mid June. The moon should be waxing and close to its opposition with the sun, because at this point the plant is in its perfection and gives a lot of salt, more than it would at other times and of better nature, strength and whiteness.

At first, it is tempting to dismiss this lunar influence as the product of a fertile imagination, but let us take a closer look. Tidal forces of the moon do in fact subtly affect plants, fish and animals in ways that can be measured. A closer look at Neri’s advice reveals reasoning that is hard to dismiss as mere astrological superstition. When the moon is waxing, tides rise and so do water tables. According to folklore, this is when sap rises from the roots of plants into stems and leaves. Sap carries the dissolved mineral salts required for glass. Neri also stipulates that harvesting should take place during lunar opposition. When the moon is 'opposed' to the sun, it is on the opposite side of the earth from the sun. In opposition, the moon is near full and rises as the sun sets. Plants see more light at night, leading to increased photosynthesis and growth.

In contrast, violinmakers from Cremona valued high alpine spruce called moon wood. Trees were felled in the wintertime, when lunar tides were low. This minimized the amount of vibration deadening sap in the wood. In his Natural History, Pliny relates Cato’s advice on felling trees in accordance with the lunar cycle. In fact, centuries-old tradition specified lunar conditions for a host of needs from construction timbers to cheese boxes. 

Great Princes

Today, we recognize L'Arte Vetraria as the first printed book solely devoted to the art of glass formulation. It is a work committed to the subject of refining raw materials and combining them into a range of glasses, over a rainbow of colors. 'First in print' is a notable distinction, but one that is surpassed with ease by Neri's deeper accomplishment. His book provides a rare glimpse of skilled practical knowledge. This was an era when prized techniques were frequently lost to subsequent generations; lost because artisans so often spared the pen. Their precious knowledge went purposely unrecorded, passing in strict confidence from master to apprentice working side by side. In 1612, Neri published his expertise to the world, dedicating his book to Prince Don Antonio de' Medici the son of Grand Duke Francesco I:

In all consideration, it is my proud duty to dedicate this book to none other than you, most Illustrious Excellency; for you have always been my outstanding patron. You are a gifted leader in this and in all other noble and worthy developments made continually in all the arts.

The prince had played a major part in Neri's life, elevating him into the upper stratum of Florentine craftsmen and to the forefront of alchemical research in Europe. However, in another manuscript, Discorso, we see a different side of Neri. On the subject of turning base metals into gold, the priest was less forthcoming:

I would add that God's providence over human affairs must not easily allow many to acquire this art, particularly not the great princes. It should not be made clear and common to the vulgar, because in this way, gold and silver and consequently coins lose their value, so that the good order of human trade will be disrupted and we should go back to the ancient barter of things that are necessary to a civil life, creating great disruption and confusion.

Eyes of a Lynx

In 1614, the year of Antonio Neri's death, naturalist Prince Federico Cesi wrote to his good friend Galileo. He complains of the difficulties in getting material from the Roman libraries, urging the astronomer to send him a copy of Antonio Neri's book.

The poor management of these libraries in Rome makes me feel continually thirsty for good books that come to light, which I can use for my study of compositions. They are scarcely giving me the titles, and after a long wait, only a tenth of what I asked. […] now I hear that printed in Florence is L’Arte Vetraria by Priest Antonio Neri, and I think there is some good in it. Please, your lordship, send me a copy, and believe me that I will gladly give them trouble. . .

Shortly after, having received the book the prince wrote,

I thank your lordship for the book on glass, which I find very rich in experiments and beautiful artistry.

In 1603, Cesi founded the Accademia dei Lincei (Society of the Lynxes), an early scientific society whose members (with eyes as sharp as a lynx’s) eventually included both Galileo Galilei and Giambattista Della Porta. Within a few months of Neri's death, his book was already on its way to making history.