Glass Discovery Legend

Giovan Maria Butteri,

"The Discovery of Glass"
Studiolo of Francesco I de' Medici

Any self-respecting Roman historian living in the first century could tell you the story that glass was first discovered by Phoenician sailors. They were temporarily grounded at the bay of Haifa, near the Belus River, in the shadow of Mount Carmel, forced ashore by a storm. Needing to eat, they improvised a fire on the beach in order to cook their food. Using natron, a mineral they were carrying as cargo on the ship, they built up a stove. To their amazement, in the heat of the fire, the natron mixed with the beach sand started to melt and liquid glass trickled out.

Actually, starting with Pliny the Elder, the author of most famous version of this story, skepticism abounds about how much of it was true. Nevertheless, if we gently tease apart the loose threads of this yarn we find that it is not without substance. First, there is the location; not just any port in a storm, this region was the site of a thriving glass industry as early as the sixth century BCE, due to the exceptional, pure white sand at the outlet of the Belus river. Archaeologists have excavated ancient glass furnaces at the nearby cities of Tyre and Sidon.

Next, the sodium carbonates in natron do indeed form glass when mixed with fine sand and brought to a high temperature, but this takes strong, concentrated heat, likely more than could be provided by a cook's beach fire. Natron is a hydroscopic mineral – this means it pulls moisture out of the surrounding environment. The water is locked into its solid crystal structure, where it remains until it is released either chemically or through heat. Natron can hold a remarkable amount of water, up to two-thirds of its weight. This is why it was used extensively to preserve mummies in Egypt; it dried out the bodies, quickly preserving them. While the story of the Phoenician sailors deserves a healthy dose of skepticism, it is also easy to see how the decomposition of the natron in the fire, resulting in the release of briny liquor, might be misinterpreted as glass.

In the early 1600s glassmaker and alchemist Antonio Neri published the first printed book of glass recipes, and in his introduction he too recounts the tale. However, in Neri's telling, natron does not make an appearance. Instead, the sailors use 'kali,' a coastal plant that is rich in alkali salts, to fuel their fire. The salts in kali are substantially similar to natron and, according to the story, triggered a similar result. In this period, Kali ash was a well-known ingredient in glass making. Neri used it in his own recipes, so the substitution is not surprising, but in this respect, Neri's version of the story does appear to be unique in the literature. It is interesting to note that Lodovico Domenichi, who was good friends with Neri's grandfather, tells a version of this story in his Italian translation of Pliny's Natural History. Here the sailors use natron, but in the next paragraph, Domenichi describes how local natives later used the plants to make their own glass.

The above depiction of the discovery of glass was painted by Butteri, one of a select group of painters for the Medici court in Florence. The work was commissioned to hang in the secret "studiolo" of Francesco de' Medici, a concealed barrel vaulted room tucked under a staircase in the Palazzo Vecchio in the early 1570's. It was only accessible through secret passages, one leading from Francesco's bed chamber. Another led from the chamber to an unmarked door on the street and a third passage led from the chamber to the secret treasury room once used by his father, Grand Duke Cosimo I. The walls and ceiling were entirely filled with paintings, the lower ones concealing cabinets full of oddities of nature, precious gems, coins, alchemical concoctions, and other treasures. Presumably, the cabinet behind Butteri's "Discovery of glass" would house some of the intricate Venetian glass vessels for which the craftsmen of Murano had become world famous. Shortly before the room was completed, a small number of these glass masters were allowed to teach their secrets in Florence by special arrangement with the Venetian government.

This post first appeared in a shorter form here on 9 October 2013.

Glass Discovery Legend

Giovan Maria Butteri,

"The Discovery of Glass"
Studiolo of Francesco I de' Medici

Any self-respecting Roman historian living in the first century could tell you the story that glass was first discovered by Phoenician sailors. They were temporarily grounded at the bay of Haifa, near the Belus River, in the shadow of Mount Carmel, forced ashore by a storm. Needing to eat, they improvised a fire on the beach in order to cook their food. Using natron, a mineral they were carrying as cargo on the ship, they built up a stove. To their amazement, in the heat of the fire, the natron mixed with the beach sand started to melt and liquid glass trickled out.

Actually, starting with Pliny the Elder, the author of most famous version of this story, skepticism abounds about how much of it was true. Nevertheless, if we gently tease apart the loose threads of this yarn we find that it is not without substance. First, there is the location; not just any port in a storm, this region was the site of a thriving glass industry as early as the sixth century BCE, due to the exceptional, pure white sand at the outlet of the Belus river. Archaeologists have excavated ancient glass furnaces at the nearby cities of Tyre and Sidon.

Next, the sodium carbonates in natron do indeed form glass when mixed with fine sand and brought to a high temperature, but this takes strong, concentrated heat, likely more than could be provided by a cook's beach fire. Natron is a hydroscopic mineral – this means it pulls moisture out of the surrounding environment. The water is locked into its solid crystal structure, where it remains until it is released either chemically or through heat. Natron can hold a remarkable amount of water, up to two-thirds of its weight. This is why it was used extensively to preserve mummies in Egypt; it dried out the bodies, quickly preserving them. While the story of the Phoenician sailors deserves a healthy dose of skepticism, it is also easy to see how the decomposition of the natron in the fire, resulting in the release of briny liquor, might be misinterpreted as glass.

In the early 1600s glassmaker and alchemist Antonio Neri published the first printed book of glass recipes, and in his introduction he too recounts the tale. However, in Neri's telling, natron does not make an appearance. Instead, the sailors use 'kali,' a coastal plant that is rich in alkali salts, to fuel their fire. The salts in kali are substantially similar to natron and, according to the story, triggered a similar result. In this period, Kali ash was a well-known ingredient in glass making. Neri used it in his own recipes, so the substitution is not surprising, but in this respect, Neri's version of the story does appear to be unique in the literature. It is interesting to note that Lodovico Domenichi, who was good friends with Neri's grandfather, tells a version of this story in his Italian translation of Pliny's Natural History. Here the sailors use natron, but in the next paragraph, Domenichi describes how local natives later used the plants to make their own glass.

The above depiction of the discovery of glass was painted by Butteri, one of a select group of painters for the Medici court in Florence. The work was commissioned to hang in the secret "studiolo" of Francesco de' Medici, a concealed barrel vaulted room tucked under a staircase in the Palazzo Vecchio in the early 1570's. It was only accessible through secret passages, one leading from Francesco's bed chamber. Another led from the chamber to an unmarked door on the street and a third passage led from the chamber to the secret treasury room once used by his father, Grand Duke Cosimo I. The walls and ceiling were entirely filled with paintings, the lower ones concealing cabinets full of oddities of nature, precious gems, coins, alchemical concoctions, and other treasures. Presumably, the cabinet behind Butteri's "Discovery of glass" would house some of the intricate Venetian glass vessels for which the craftsmen of Murano had become world famous. Shortly before the room was completed, a small number of these glass masters were allowed to teach their secrets in Florence by special arrangement with the Venetian government.

This post first appeared in a shorter form here on 9 October 2013.

Secret Laboratory

The Studiolo of Francesco de' Medici,

Palazzo Vecchio, Florence.

In all likelihood, Antonio Neri started his glassmaking career around 1601 in the laboratory palace of Medici prince Don Antonio. The Casino di San Marco is located on the north side of Florence, not far from where the old city walls once stood. It was purpose-built as a laboratory by Don Antonio’s father, Grand Duke Francesco and stands on the former location of the sculptural school that Michelangelo attended as a boy. The Casino is a remarkable structure in the history of science, however, our subject today is not the laboratory but one of its primary inspirations, located across town in the Palazzo Vecchio; The Studiolo of Francesco de’ Medici.

Books of secrets, like Neri’s L’Arte Vetraria exposed methods to transform nature. Cabinets of curiosities, on the other hand, celebrated the finished products as well as nature’s ready-made treasures. These so-called cabinets were a sort of physical counterpart to books of secrets. Starting as small collections of exotic objects, princes and nobles strove to out-do each other and the largest examples encompassed entire rooms. In the early 1570s, at around age thirty, Francesco de’ Medici initiated a special project; he constructed a secret room in the Palazzo Vecchio. [1] Accessible through a concealed staircase in his bedroom, this small, but opulent, study chamber was devoted to natural curiosities and secrets. The “Studiolo” contained his collection of rare gems, exotic seashells, animal horns, chemicals, potions, scientific instruments and other strange and wonderful treasures collected from around the world. 

From floor to barrel-vaulted ceiling, paintings and niched sculptures covered the chamber walls. Celebrated artist Giorgio Vasari designed and constructed the secret room in partnership with Vincenzo Borghini, a Benedictine priest and close Medici advisor. [2]  In all, thirty-two of the city’s artists contributed to the project, although most had no idea where their work was destined to hang. Francesco organized paintings such that each wall was themed by one of the four Aristotelian elements: air, earth, water and fire. Behind nineteen of the lower paintings, cabinets housed the treasures of Francesco’s collection. From within the Studiolo two other secret passages were accessible from behind concealed panels. One leads to a smaller private treasury once used by Francesco’s father, Cosimo and another leads down a stairs to an unmarked outside door on the street. [3]

Part study and part museum, Francesco used the Studiolo to escape public life and explore the secrets of nature. This menagerie and ones like it were an outgrowth of the wunderkammer or “cabinet of curiosities.” Early in their evolution, they took the form of single pieces of furniture for the display of collections. Monarchs and nobles throughout Europe boasted collections of ever-increasing size and diversity. In a way, the Casino di San Marco was the next evolutionary step; from a cabinet of curiosities, to a study room, to an entire facility devoted to nature’s secrets. 

The paintings in Francesco’s Studiolo depict various religious, mythological, historical and industrial scenes. [4] Some of them show various royal workshops documenting activities as diverse as goldsmithing and wool dying. A 1571 painting by Giovanni Stradano [5] is entitled the Alchemy Studio. It shows Francesco I in the Uffizi surrounded by laboratory equipment and workers. 

[1] Constructed between 1567 and 1675, cf. Feinberg 2002, Edwards 2007.
[2] Giorgio Vasari (1511–1574), Vincenzo Borghini (1515–1580).
[3] Via della Nina.
[4] Feinberg 2002.
[5] Giovanni Stradano, also called Jan van der Straet (1523–1605).

The Discovery of Glass

Giovan Maria Butteri,

"The Discovery of Glass"
Studiolo of Francesco I de' Medici

Any self-respecting Roman historian living in the first century could tell you the story that glass was first discovered by Phoenician sailors. They were temporarily grounded at the bay of Haifa, near the Belus River, in the shadow of Mount Carmel, forced ashore by a storm. Needing to eat, they improvised a fire on the beach in order to cook their food. Using natron, a mineral they were carrying as cargo on the ship, they built up a stove. To their amazement, in the heat of the fire, the natron mixed with the beach sand started to melt and liquid glass trickled out.

Actually, starting with Pliny the Elder, the author of most famous version of this story, skepticism abounds about how much of it was true. Nevertheless, if we gently tease apart the loose threads of this yarn we find that it is not without substance. First, there is the location; not just any port in a storm, this region was the site of a thriving glass industry as early as the sixth century BCE, due to the exceptional, pure white sand at the outlet of the Belus river. Archaeologists have excavated ancient glass furnaces at the nearby cities of Tyre and Sidon.

Next, the sodium carbonates in natron do indeed form glass when mixed with fine sand and brought to a high temperature, but this takes strong, concentrated heat, likely more than could be provided by a cook's beach fire. Natron is a hydroscopic mineral – this means it pulls moisture out of the surrounding environment. The water is locked into its solid crystal structure, where it remains until it is released either chemically or through heat. Natron can hold a remarkable amount of water, up to two-thirds of its weight. This is why it was used extensively to preserve mummies in Egypt; it dried out the bodies, quickly preserving them. While the story of the Phoenician sailors deserves a healthy dose of skepticism, it is also easy to see how the decomposition of the natron in the fire, resulting in the release of briny liquor, might be misinterpreted as glass.

In the early 1600s glassmaker and alchemist Antonio Neri published the first printed book of glass recipes, and in his introduction he too recounts the tale. However, in Neri's telling, natron does not make an appearance. Instead, the sailors use 'kali,' a coastal plant that is rich in alkali salts, to fuel their fire. The salts in kali are substantially similar to natron and, according to the story, triggered a similar result. In this period, Kali ash was a well-known ingredient in glass making. Neri used it in his own recipes, so the substitution is not surprising, but in this respect, Neri's version of the story does appear to be unique in the literature. It is interesting to note that Lodovico Domenichi, who was good friends with Neri's grandfather, tells a version of this story in his Italian translation of Pliny's Natural History. Here the sailors use natron, but in the next paragraph, Domenichi describes how local natives later used the plants to make their own glass.

The above depiction of the discovery of glass was painted by Butteri, one of a select group of painters for the Medici court in Florence. The work was commissioned to hang in the secret "studiolo" of Francesco de' Medici, a concealed barrel vaulted room tucked under a staircase in the Palazzo Vecchio in the early 1570's. It was only accessible through secret passages, one leading from Francesco's bed chamber. Another led from the chamber to an unmarked door on the street and a third passage led from the chamber to the secret treasury room once used by his father, Grand Duke Cosimo I. The walls and ceiling were entirely filled with paintings, the lower ones concealing cabinets full of oddities of nature, precious gems, coins, alchemical concoctions, and other treasures. Presumably, the cabinet behind Butteri's "Discovery of glass" would house some of the intricate Venetian glass vessels for which the craftsmen of Murano had become world famous. Shortly before the room was completed, a small number of these glass masters were allowed to teach their secrets in Florence by special arrangement with the Venetian government.

This post first appeared in a shorter form here on 9 October 2013.

Francesco's Secret Laboratory

The Studiolo of Francesco de' Medici,

Palazzo Vecchio, Florence.

In all likelihood, Antonio Neri started his glassmaking career around 1601 in the laboratory palace of Medici prince Don Antonio. The Casino di San Marco is located on the north side of Florence, not far from where the old city walls once stood. It was purpose-built as a laboratory by Don Antonio’s father, Grand Duke Francesco and stands on the former location of the sculptural school that Michelangelo attended as a boy. The Casino is a remarkable structure in the history of science, however, our subject today is not the laboratory but one of its primary inspirations, located across town in the Palazzo Vecchio; The Studiolo of Francesco de’ Medici.

Books of secrets, like Neri’s L’Arte Vetraria exposed methods to transform nature. Cabinets of curiosities, on the other hand, celebrated the finished products as well as nature’s ready-made treasures. These so-called cabinets were a sort of physical counterpart to books of secrets. Starting as small collections of exotic objects, princes and nobles strove to out-do each other and the largest examples encompassed entire rooms. In the early 1570s, at around age thirty, Francesco de’ Medici initiated a special project; he constructed a secret room in the Palazzo Vecchio. [1] Accessible through a concealed staircase in his bedroom, this small, but opulent, study chamber was devoted to natural curiosities and secrets. The “Studiolo” contained his collection of rare gems, exotic seashells, animal horns, chemicals, potions, scientific instruments and other strange and wonderful treasures collected from around the world. 

From floor to barrel-vaulted ceiling, paintings and niched sculptures covered the chamber walls. Celebrated artist Giorgio Vasari designed and constructed the secret room in partnership with Vincenzo Borghini, a Benedictine priest and close Medici advisor. [2]  In all, thirty-two of the city’s artists contributed to the project, although most had no idea where their work was destined to hang. Francesco organized paintings such that each wall was themed by one of the four Aristotelian elements: air, earth, water and fire. Behind nineteen of the lower paintings, cabinets housed the treasures of Francesco’s collection. From within the Studiolo two other secret passages were accessible from behind concealed panels. One leads to a smaller private treasury once used by Francesco’s father, Cosimo and another leads down a stairs to an unmarked outside door on the street. [3]

Part study and part museum, Francesco used the Studiolo to escape public life and explore the secrets of nature. This menagerie and ones like it were an outgrowth of the wunderkammer or “cabinet of curiosities.” Early in their evolution, they took the form of single pieces of furniture for the display of collections. Monarchs and nobles throughout Europe boasted collections of ever-increasing size and diversity. In a way, the Casino di San Marco was the next evolutionary step; from a cabinet of curiosities, to a study room, to an entire facility devoted to nature’s secrets. 

The paintings in Francesco’s Studiolo depict various religious, mythological, historical and industrial scenes. [4] Some of them show various royal workshops documenting activities as diverse as goldsmithing and wool dying. A 1571 painting by Giovanni Stradano [5] is entitled the Alchemy Studio. It shows Francesco I in the Uffizi surrounded by laboratory equipment and workers. 

[1] Constructed between 1567 and 1675, cf. Feinberg 2002, Edwards 2007.
[2] Giorgio Vasari (1511–1574), Vincenzo Borghini (1515–1580).
[3] Via della Nina.
[4] Feinberg 2002.
[5] Giovanni Stradano, also called Jan van der Straet (1523–1605).

Francesco's Studiolo

The Studiolo of Francesco de' Medici,

Palazzo Vecchio, Florence.
(click to enlarge)

In all likelihood, Antonio Neri started his glass- making career around 1601 in the laboratory palace of Medici prince Don Antonio. The Casino di San Marco is located on the north side of Florence, not far from where the old northern city walls once stood. It was purpose-built as a laboratory by Don Antonio’s father, Grand Duke Francesco and stands on the former location of the sculptural school that Michelangelo attended as a boy. The Casino is a remarkable structure in the history of science, however, our subject today is not the laboratory but one of its primary inspirations, and direct predecessor, located across town in the Palazzo Vecchio; The Studiolo of Francesco de’ Medici.

Books of secrets, like Neri’s L’Arte Vetraria exposed methods to transform nature. Cabinets of curiosities, on the other hand, celebrated the finished products as well as nature’s ready-made treasures. These so-called cabinets were a sort of physical counterpart to books of secrets. Starting as small collections of exotic objects, princes and nobles strove to out-do each other and the largest examples encompassed entire rooms. In the early 1570s, at around age thirty, Francesco de’ Medici initiated a special secret project; he constructed a room in the Palazzo Vecchio under a grand stairwell. [1] Accessible through a concealed passage in his bedroom, this small, but opulent, study chamber was devoted to natural curiosities and secrets. The “Studiolo” contained his collection of rare gems, exotic seashells, animal horns, chemicals, potions, scientific instruments and other strange and wonderful treasures collected from around the world. It also allowed him to spy through a peep-hole on proceedings in the cavernous "Hall of the Five Hundred" where Tuscany's legislature met.

From floor to barrel-vaulted ceiling, paintings and niched sculptures covered the chamber walls. Celebrated artist Giorgio Vasari designed and constructed the secret room in partnership with Vincenzo Borghini, a Benedictine priest and close Medici advisor. [2]  In all, thirty-two of the city’s artists contributed to the project, although most had no idea where their work was destined to hang. Francesco organized paintings such that each wall was themed by one of the four Aristotelian elements: air, earth, water and fire. Behind nineteen of the lower paintings, cabinets housed the treasures of Francesco’s collection. From within the Studiolo two other secret passages were accessible from behind concealed panels. One leads to a smaller private treasury once used by Francesco’s father, Cosimo and another leads down a stairs to an unmarked outside door on the street. [3]

Part study and part museum, Francesco used the Studiolo to escape public life and explore the secrets of nature. This menagerie and ones like it were an outgrowth of the wunderkammer or “cabinet of curiosities.” Early in their evolution, they conceptually took the form of single pieces of furniture for the display of collections. Monarchs and nobles throughout Europe boasted collections of ever-increasing size and diversity. In a way, the Casino di San Marco was the next evolutionary step; from a cabinet of curiosities, to a study room, to an entire facility devoted to nature’s secrets. 

The paintings in Francesco’s Studiolo depict various religious, mythological, historical and industrial scenes. [4] Some of them show various royal workshops documenting activities as diverse as goldsmithing and wool dying. A 1571 painting by Giovanni Stradano [5] is entitled the Alchemy Studio. It shows Francesco I de Medici in the Uffizi surrounded by laboratory equipment and workers. Another shows the myth of the discovery of glass at the mouth of the Bellus river in the Levant.

[1] Constructed between 1567 and 1675, cf. Feinberg 2002, Edwards 2007.
[2] Giorgio Vasari (1511–1574), Vincenzo Borghini (1515–1580).
[3] Via della Nina.
[4] Feinberg 2002.

[5] Giovanni Stradano, also called Jan van der Straet (1523–1605).

Discovery of Glass

Giovan Maria Butteri,

"The Discovery of Glass"
Studiolo of Francesco I de' Medici

Any self-respecting Roman historian living in the first century could tell you the story that glass was first discovered by Phoenician sailors. They were temporarily grounded at the bay of Haifa, near the Belus River, in the shadow of Mount Carmel, forced ashore by a storm. Needing to eat, they improvised a fire on the beach in order to cook their food. Using natron, a mineral they were carrying as cargo on the ship, they built up a stove. To their amazement, in the heat of the fire, the natron mixed with the beach sand started to melt and liquid glass trickled out.

Actually, starting with Pliny the Elder, the author of most famous version of this story, skepticism abounds about how much of it was true. Nevertheless, if we gently tease apart the loose threads of this yarn we find that it is not without substance. First, there is the location; not just any port in a storm, this region was the site of a thriving glass industry as early as the sixth century BCE, due to the exceptional, pure white sand at the outlet of the Belus river. Archaeologists have excavated ancient glass furnaces at the nearby cities of Tyre and Sidon.

Next, the sodium carbonates in natron do indeed form glass when mixed with fine sand and brought to a high temperature, but this takes strong, concentrated heat, likely more than could be provided by a cook's beach fire. Natron is a hydroscopic mineral – this means it pulls moisture out of the surrounding environment. The water is locked into its solid crystal structure, where it remains until it is released either chemically or through heat. Natron can hold a remarkable amount of water, up to two-thirds of its weight. This is why it was used extensively to preserve mummies in Egypt; it dried out the bodies, quickly preserving them. While the story of the Phoenician sailors deserves a healthy dose of skepticism, it is also easy to see how the decomposition of the natron in the fire, resulting in the release of briny liquor, might be misinterpreted as glass.

In the early 1600s glassmaker and alchemist Antonio Neri published the first printed book of glass recipes, and in his introduction he too recounts the tale. However, in Neri's telling, natron does not make an appearance. Instead, the sailors use 'kali,' a coastal plant that is rich in alkali salts, to fuel their fire. The salts in kali are substantially similar to natron and, according to the story, triggered a similar result. In this period, Kali ash was a well-known ingredient in glass making. Neri used it in his own recipes, so the substitution is not surprising, but in this respect, Neri's version of the story does appear to be unique in the literature. It is interesting to note that Lodovico Domenichi, who was good friends with Neri's grandfather, tells a version of this story in his Italian translation of Pliny's Natural History. Here the sailors use natron, but in the next paragraph, Domenichi describes how local natives later used the plants to make their own glass.

The above depiction of the discovery of glass was painted by Butteri, one of a select group of painters for the Medici court in Florence. The work was commissioned to hang in the secret "studiolo" of Francesco de' Medici, a concealed barrel vaulted room tucked under a staircase in the Palazzo Vecchio in the early 1570's. It was only accessible through secret passages, one leading from Francesco's bed chamber. Another led from the chamber to an unmarked door on the street and a third passage led from the chamber to the secret treasury room once used by his father, Grand Duke Cosimo I. The walls and ceiling were entirely filled with paintings, the lower ones concealing cabinets full of oddities of nature, precious gems, coins, alchemical concoctions, and other treasures. Presumably, the cabinet behind Butteri's "Discovery of glass" would house some of the intricate Venetian glass vessels for which the craftsmen of Murano had become world famous. Shortly before the room was completed, a small number of these glass masters were allowed to teach their secrets in Florence by special arrangement with the Venetian government.

This post first appeared in a shorter form here on 9 October 2013.

Francesco's Studiolo

The Studiolo of Francesco de' Medici,

Palazzo Vecchio, Florence.
(click to enlarge)

In all likelihood, Antonio Neri started his glassmaking career around 1601 in the laboratory palace of Medici prince Don Antonio. The Casino di San Marco is located on the north side of Florence, not far from where the old city walls once stood. It was purpose-built as a laboratory by Don Antonio’s father, Grand Duke Francesco and stands on the former location of the sculptural school that Michelangelo attended as a boy. The Casino is a remarkable structure in the history of science, however, our subject today is not the laboratory but one of its primary inspirations, located across town in the Palazzo Vecchio; The Studiolo of Francesco de’ Medici.

Books of secrets, like Neri’s L’Arte Vetraria exposed methods to transform nature. Cabinets of curiosities, on the other hand, celebrated the finished products as well as nature’s ready-made treasures. These so-called cabinets were a sort of physical counterpart to books of secrets. Starting as small collections of exotic objects, princes and nobles strove to out-do each other and the largest examples encompassed entire rooms. In the early 1570s, at around age thirty, Francesco de’ Medici initiated a special project; he constructed a secret room in the Palazzo Vecchio. [1] Accessible through a concealed staircase in his bedroom, this small, but opulent, study chamber was devoted to natural curiosities and secrets. The “Studiolo” contained his collection of rare gems, exotic seashells, animal horns, chemicals, potions, scientific instruments and other strange and wonderful treasures collected from around the world. 

From floor to barrel-vaulted ceiling, paintings and niched sculptures covered the chamber walls. Celebrated artist Giorgio Vasari designed and constructed the secret room in partnership with Vincenzo Borghini, a Benedictine priest and close Medici advisor. [2]  In all, thirty-two of the city’s artists contributed to the project, although most had no idea where their work was destined to hang. Francesco organized paintings such that each wall was themed by one of the four Aristotelian elements: air, earth, water and fire. Behind nineteen of the lower paintings, cabinets housed the treasures of Francesco’s collection. From within the Studiolo two other secret passages were accessible from behind concealed panels. One leads to a smaller private treasury once used by Francesco’s father, Cosimo and another leads down a stairs to an unmarked outside door on the street. [3]

Part study and part museum, Francesco used the Studiolo to escape public life and explore the secrets of nature. This menagerie and ones like it were an outgrowth of the wunderkammer or “cabinet of curiosities.” Early in their evolution, they took the form of single pieces of furniture for the display of collections. Monarchs and nobles throughout Europe boasted collections of ever-increasing size and diversity. In a way, the Casino di San Marco was the next evolutionary step; from a cabinet of curiosities, to a study room, to an entire facility devoted to nature’s secrets. 

The paintings in Francesco’s Studiolo depict various religious, mythological, historical and industrial scenes. [4] Some of them show various royal workshops documenting activities as diverse as goldsmithing and wool dying. A 1571 painting by Giovanni Stradano [5] is entitled the Alchemy Studio. It shows Francesco I in the Uffizi surrounded by laboratory equipment and workers. 

[1] Constructed between 1567 and 1675, cf. Feinberg 2002, Edwards 2007.
[2] Giorgio Vasari (1511–1574), Vincenzo Borghini (1515–1580).
[3] Via della Nina.
[4] Feinberg 2002.

[5] Giovanni Stradano, also called Jan van der Straet (1523–1605).

The Discovery of Glass

Giovan Maria Butteri,
"The Discovery of Glass"
Studiolo of Francesco I de' Medici

Any self-respecting Roman historian living in the first century could tell you the story that glass was first discovered by Phoenician sailors. They were temporarily grounded at the bay of Haifa, near the Belus River, in the shadow of Mount Carmel, forced ashore by a storm. Needing to eat, they improvised a fire on the beach in order to cook their food. Using natron, a mineral they were carrying as cargo on the ship, they built up a stove. To their amazement, in the heat of the fire, the natron mixed with the beach sand started to melt and liquid glass trickled out.

Actually, ever since Pliny the Elder, the author of most famous version of this story, skepticism abounds about how much of it was true. Nevertheless, if we gently tease apart the loose threads of this yarn we find that it is not without substance. First, there is the location; not just any port in a storm, this region was the site of a thriving glass industry as early as the sixth century BCE, due to the exceptional, pure white sand at the outlet of the Belus river. Archaeologists have excavated ancient glass furnaces at the nearby cities of Tyre and Sidon.

Next, the sodium carbonates in natron do indeed form glass when mixed with fine sand and brought to a high temperature, but this takes strong, concentrated heat, likely more than could be provided by a cook's beach fire. Natron is a hydroscopic mineral – this means it pulls moisture out of the surrounding environment. The water is locked into its solid crystal structure, where it remains until it is released either chemically or through heat. Natron can hold a remarkable amount of water, up to two-thirds of its weight. This is why it was used extensively to preserve mummies in Egypt; it dried out the bodies, quickly preserving them. While the story of the Phoenician sailors deserves a healthy dose of skepticism, it is also easy to see how the decomposition of the natron in the fire, resulting in the release of briny liquor, might be misinterpreted as glass.

In Neri's telling, natron does not make an appearance. Instead, the sailors use 'kali,' a coastal plant that is rich in alkali salts, to fuel their fire. The salts in kali are substantially similar to natron and, according to the story, triggered a similar result. Kali ash was a well-known ingredient in glass making. Neri used it in his own glass recipes, so the substitution is not surprising, but this version of the story does appear to be unique in the literature. It is interesting to note that Lodovico Domenichi, who was good friends with Neri's grandfather, tells a version of this story in his translation of Pliny's Natural History. Here the sailors use natron, but in the next paragraph, Domenichi describes how local natives used the plants to make their own glass.

The above depiction of the discovery of glass was painted by Butteri, one of a select group of painters for the Medici court in Florence. The work was commissioned to hang in the secret "studiolo" of Francesco de' Medici, a barrel vaulted room tucked under a staircase in the Palazzo Vecchio in the early 1570's. It was only accessible through secret passages, one leading from Francesco's bed chamber. Another passage lead to an unmarked door on the street and a third passage led to the secret treasury room once used by his father, Grand Duke Cosimo I. The walls and ceiling were entirely filled with paintings, the lower ones concealing cabinets full of oddities of nature, precious gems, coins, alchemical concoctions, and other treasures. Presumably, the cabinet behind Butteri's "Discovery of glass" would house some of the intricate Venetian glass vessels for which the craftsmen of Murano had become world famous. Shortly before the room was completed, a small number of these glass masters were allowed to teach their secrets in Florence by special arrangement with the Venetian government.

This post first appeared in a shorter form here on 9 October 2013.

Francesco's Studiolo

The Studiolo of Francesco de' Medici,
Palazzo Vecchio, Florence.

In all likelihood, Antonio Neri started his glassmaking career around 1601 in the laboratory palace of Medici prince Don Antonio. The Casino di San Marco is located on the north side of Florence, not far from where the old city walls once stood. It was purpose-built as a laboratory by Don Antonio’s father, Grand Duke Francesco and stands on the former location of the sculptural school that Michelangelo attended as a boy. The Casino is a remarkable structure in the history of science, however, our subject today is not the laboratory but one of its primary inspirations, located across town in the Palazzo Vecchio; The Studiolo of Francesco de’ Medici.

Books of secrets, like Neri’s L’Arte Vetraria exposed methods to transform nature. Cabinets of curiosities, on the other hand, celebrated the finished products as well as nature’s ready-made treasures. These so-called cabinets were a sort of physical counterpart to books of secrets. Starting as small collections of exotic objects, princes and nobles strove to out-do each other and the largest examples encompassed entire rooms. In the early 1570s, at around age thirty, Francesco de’ Medici initiated a special project; he constructed a secret room in the Palazzo Vecchio. [1] Accessible through a concealed staircase in his bedroom, this small, but opulent, study chamber was devoted to natural curiosities and secrets. The “Studiolo” contained his collection of rare gems, exotic seashells, animal horns, chemicals, potions, scientific instruments and other strange and wonderful treasures collected from around the world. 

From floor to barrel-vaulted ceiling, paintings and niched sculptures covered the chamber walls. Celebrated artist Giorgio Vasari designed and constructed the secret room in partnership with Vincenzo Borghini, a Benedictine priest and close Medici advisor. [2]  In all, thirty-two of the city’s artists contributed to the project, although most had no idea where their work was destined to hang. Francesco organized paintings such that each wall was themed by one of the four Aristotelian elements: air, earth, water and fire. Behind nineteen of the lower paintings, cabinets housed the treasures of Francesco’s collection. From within the Studiolo two other secret passages were accessible from behind concealed panels. One leads to a smaller private treasury once used by Francesco’s father, Cosimo and another leads down a stairs to an unmarked outside door on the street. [3]

Part study and part museum, Francesco used the Studiolo to escape public life and explore the secrets of nature. This menagerie and ones like it were an outgrowth of the wunderkammer or “cabinet of curiosities.” Early in their evolution, they took the form of single pieces of furniture for the display of collections. Monarchs and nobles throughout Europe boasted collections of ever-increasing size and diversity. In a way, the Casino di San Marco was the next evolutionary step; from a cabinet of curiosities, to a study room, to an entire facility devoted to nature’s secrets. 

The paintings in Francesco’s Studiolo depict various religious, mythological, historical and industrial scenes. [4] Some of them show various royal workshops documenting activities as diverse as goldsmithing and wool dying. A 1571 painting by Giovanni Stradano [5] is entitled the Alchemy Studio. It shows Francesco I in the Uffizi surrounded by laboratory equipment and workers. 

[1] Constructed between 1567 and 1675, cf. Feinberg 2002, Edwards 2007.
[2] Giorgio Vasari (1511–1574), Vincenzo Borghini (1515–1580).
[3] Via della Nina.
[4] Feinberg 2002.
[5] Giovanni Stradano, also called Jan van der Straet (1523–1605).

The Discovery of Glass Reprise

Giovan Maria Butteri,
"The Discovery of Glass"
Studiolo of Francesco I de' Medici

Any self-respecting Roman historian living in the first century could tell you the story that glass was first discovered by Phoenician sailors. They were temporarily grounded at the bay of Haifa, near the Belus River, in the shadow of Mount Carmel, forced ashore by a storm. Needing to eat, they improvised a fire on the beach in order to cook their food. Using natron, a mineral they were carrying as cargo on the ship, they built up a stove. To their amazement, in the heat of the fire, the natron mixed with the beach sand started to melt and liquid glass trickled out.

Actually, ever since Pliny the Elder, the author of most famous version of this story, skepticism abounds about how much of it was true. Nevertheless, if we gently tease apart the loose threads of this yarn we find that it is not without substance. First, there is the location; not just any port in a storm, this region was the site of a thriving glass industry as early as the sixth century BCE, due to the exceptional, pure white sand at the outlet of the Belus river. Archaeologists have excavated ancient glass furnaces at the nearby cities of Tyre and Sidon.

Next, the sodium carbonates in natron do indeed form glass when mixed with fine sand and brought to a high temperature, but this takes strong, concentrated heat, likely more than could be provided by a cook's beach fire. Natron is a hydroscopic mineral – this means it pulls moisture out of the surrounding environment. The water is locked into its solid crystal structure, where it remains until it is released either chemically or through heat. Natron can hold a remarkable amount of water, up to two-thirds of its weight. This is why it was used extensively to preserve mummies in Egypt; it dried out the bodies, quickly preserving them. While the story of the Phoenician sailors deserves a healthy dose of skepticism, it is also easy to see how the decomposition of the natron in the fire, resulting in the release of briny liquor, might be misinterpreted as glass.

In Neri's telling, natron does not make an appearance. Instead, the sailors use 'kali,' a coastal plant that is rich in alkali salts, to fuel their fire. The salts in kali are substantially similar to natron and, according to the story, triggered a similar result. Kali ash was a well-known ingredient in glass making. Neri used it in his own glass recipes, so the substitution is not surprising, but this version of the story does appear to be unique in the literature. It is interesting to note that Lodovico Domenichi, who was good friends with Neri's grandfather, tells a version of this story in his translation of Pliny's Natural History. Here the sailors use natron, but in the next paragraph, Domenichi describes how local natives used the plants to make their own glass.

The above depiction of the discovery of glass was painted by Butteri, one of a select group of painters for the Medici court in Florence. The work was commissioned to hang in the secret "studiolo" of Francesco de' Medici, a barrel vaulted room tucked under a staircase in the Palazzo Vecchio in the early 1570's. It was only accessible through secret passages, one leading from Francesco's bed chamber. Another passage lead to an unmarked door on the street and a third passage led to the secret treasury room once used by his father, Grand Duke Cosimo I. The walls and ceiling were entirely filled with paintings, the lower ones concealing cabinets full of oddities of nature, precious gems, coins, alchemical concoctions, and other treasures. Presumably, the cabinet behind Butteri's "Discovery of glass" would house some of the intricate Venetian glass vessels for which the craftsmen of Murano had become world famous. Shortly before the room was completed, a small number of these glass masters were allowed to teach their secrets in Florence by special arrangement with the Venetian government.

This post first appeared in a shorter form here on 9 October 2013.

Pictures of Neri

MS Ferguson 67, f. xxvii-v
U. of Glasgow .

There are two known likenesses of Glassmaker Antonio Neri. The first is a portrait in ink and watercolor, drawn in 1598 by the twenty-two year old Neri's own hand. It resides in the University of Glasgow special collections department, in what is his earliest known manuscript, an alchemical treatise entitled Treasure of the World. Given his birth in 1576, this writing must have been started a very short time after Neri's ordination as a Roman Catholic priest. This manuscript contains a number of illustrations showing both men and women performing chemical work with various apparatus and furnaces, but only this one drawing depicts the author himself. He appears leaning over a glass flask in which he is collecting saliva (for a recipe to make "sale detto sputo dell uomo" or "salt called 'spit of man'"). In part, the text reads "Of me, priest Antonio Neri Florentine 1598."

The second image of Antonio Neri takes the form of a large round plaster medallion, in bas-relief. It was probably prepared for an 1841 meeting of the "Scienziati Italiani" The Italian Congress of Science. Invitations were sent around the world and in August, guests and participants converged on Florence. After opening ceremonies in the Hall of the Five Hundred of the Palazzo Vecchio, sessions took place in the Museum of Natural History, situated next to the Pitti Palace. The museum, still open today, was the first cabinet of curiosities open to the public and dedicated to education.

MS Ferguson 67, f. xxvii-v
(detail, rotation)

Today, the museum is famous for its collection of extremely realistic, life sized, wax models of human anatomy, used in the nineteenth century by medical students in understanding the placement and structure of the body's internal organs. The Specola, which means "observatory," was so named because of the astronomical telescope that it housed. Instituted by Grand Duke

Peter Leopold in 1771, the museum was intended to store and display the collected scientific instruments, books and artifacts of the Medici dynasty. It was also to be a working research laboratory, in which the grand duke himself maintained a space. It was opened to the public in 1775 and sixty-five years later the facility underwent an overhaul, in preparation for the congress of scientists. The construction included a new hall, the Galileo Trubuna, dedicated to the remembrance of great Italian scientists, with astronomer Galileo Galilei taking the place of greatest honor. The space included a number of large marble medallions showing busts of prominent scientists in bas-relief, carved by a variety of well known sculptors of the time. The artists were Cambi, Nencini, Pozzi, Gostoli, Santerelli, Demi, Fantacchiotti, Romanelli, Pampaloni, Magi and Lusini. In addition to the marble medallions, there are a number of others scattered through the museum, executed in identical style, but in gesso. One from this second grouping shows the portrait of Antonio Neri. The artist is not known, although it is reasonable to conclude that the gesso pieces were executed by some of the same artists that carved the marble likenesses for the Tribuna.

Neri Medallion, Specola, Florence

Another possibility, just as likely is that the gesso medallions were prepared later, perhaps for museum director Hugo Schiff who, in the early 1880s founded the  Chemical Institute of the University of Florence, which included a large lecture hall "adorned with medallions and busts of the most famous chemists."

The Neri medallion presents something of a mystery in that it was executed over two centuries after his death, but the model for this likeness is unidentified. His image, in some form or other, must have been available from which the sculptor could work. To date, no such likeness other than the above has been found; the possibility of another image holds out hope for as yet undiscovered source material from the glassmaker's lifetime.