Art Center College Evolution of Chinese Pottery and Porcelain Technology Analysis

  

Description

ead the attachments two times each. First focus on content. How is porcelain defined in terms of time period, technique, and features? How does each article describe and narrate the actors (human makers, designers, scientists, and creators) who made porcelain.

During your second time reading, consider the differences between the two articles. Who is creating? When are they creating? What was required to make? How are the two historical narratives different?

In your response please try to consider (this is a guess and a thinking exercise based on the readings) how does the presentation (via the article text) of technology differ?

Bull. Hist. Chem., VOLUME 35, Number 1 (2010)
24
BÖTTGER’S EUREKA! : NEW INSIGHTS
INTO THE EUROPEAN REINVENTION OF
PORCELAIN*
Nicholas Zumbulyadis, Independent Scholar (Retired, Eastman Kodak Research
Laboratories, Rochester, NY)
Introduction
The opening of Europe’s first porcelain manufactory in
Dresden, in January, 1710 represented the successful
culmination of efforts to unlock the secret of Chinese
porcelain, a quest that had gone on for at least 800 years.
By royal decree, on the 6th of June 1710 the manufactory
was moved from Dresden to the Albrechtsburg in the city
of Meißen. Developed initially as a medium of artistic
expression, porcelain quickly became one of the most
widely used composite materials ever invented (1). The
objective of the present paper is to fill in new details about
the invention of European porcelain by examining the
plausibility of an early 19th-century account in the light of
recent analytical data together with archival material.
Porcelain was first discovered in China, with the
earliest recorded pieces dating to the T’ang Dynasty
(618-907 AD). While it is generally believed that this
discovery was accidental, Chinese porcelain does have
compositional similarities to earlier, dense, high-temperature stoneware from 200 BC to 200 AD. These wares are
known as protoporcelain, a term used more frequently in
China than in the West (2).
According to tradition, the earliest examples of
porcelain arrived in Europe from China towards the end
of the thirteenth century with the return of Marco Polo
from his legendary voyage. One cannot be certain that
this was the first encounter of Europeans with porcelain
since Chinese porcelain objects dating to 900 AD were
excavated in Samarra, Iraq. The porcelain specimens
Marco Polo brought back must have displayed properties
puzzling to the people of the Middle Ages. They were
probably white, definitely vitreous, (and hence, unlike
European pottery, nonporous) and translucent. By the
middle of the 15th century porcelain objects from the
Far East had found their way into Italian collections by
way of the Middle East, mostly through the exchange of
diplomatic gifts. Later, during the 16th and 17th centuries,
when Portuguese and Dutch traders brought back large
quantities of porcelain from China, Europeans became
widely appreciative of porcelain’s unique resistance to
thermal shock.
The problem of producing true porcelain perplexed potters and alchemists for several centuries.
Islamic potters, trying to imitate the white appearance
of porcelain, introduced tin oxide into the transparent
glaze as an opacifier. They were thus able to produce
a ceramic surface that was an ideal canvas for further
decoration. This approach ultimately led to materials
known in Europe as Italian maiolica, French faience, or
Delftware. Alchemists, both in 13th-century Persia and
later in Southern Europe, attempted to introduce the
property of translucency into the clay by mixing it with
ground glass (3). In 1575 Grand Duke Francesco Maria
de’ Medici of Florence, himself an alchemist, produced
a translucent material by co-melting kaolin-containing
clay from Vicenza and glass. Known as Medici-porcelain,
this material (one of many variants of what is now called
soft-paste porcelain or fritware) was produced until 1586
(until 1620 in Pisa), with very few pieces surviving today. While used to produce objects of great beauty and
elegance, none of these materials possessed porcelain’s
resistance to thermal shock.
Bull. Hist. Chem., VOLUME 35, Number 1 (2010)
One of the earliest attempts to break away from
these purely phenomenological approaches was made by
the English potter John Dwight (founder of the Fulham
pottery), who sought to improve German salt-glazed
ware by firing it at higher temperatures to bring about
vitrification of the clay body (4). It was, however, Johann
Friedrich Böttger (1682-1719), an alchemist in pursuit of
the philosopher’s stone, together with Ehrenfried Walther
von Tschirnhaus (1651-1708)
and their circle of laboratory
assistants and kiln builders, who
finally succeeded in reinventing
porcelain in Europe. Böttger was
both a prisoner and in the employ
of Prince-Elector Augustus the
Strong (5) and charged with making gold to finance the profligacy
of his master. In 1706 Tschirnhaus gradually nudged Böttger
towards working on porcelain.
25
of the manufacturing process are of key significance to
the reconstruction of the circumstances that led to the
reinvention of porcelain.
The starting material for porcelain is a mixture of
approximately 50% kaolinite, 25% quartz, and 25%
feldspar. Kaolinite [Al2Si2O5 (OH)4], a white-burning
clay, is structurally a phyllosilicate which can intercalate
water molecules between
its layers, thus acquiring
its unique plasticity. Kaolin
(from Chinese, kao-ling,
meaning mountain ridge)
and quartz constitute the
basic body, what the Chinese
poetically described as the
bones, of porcelain. Feldspar
[KAlSi3O8] (petuntse and
also called the flesh of porcelain by the Chinese) plays
a very special role during
While the story of the Euthe final thermal processing
ropean reinvention of porcelain
step. The components are
has been told countless times,
finely ground, thoroughly
the exact circumstances of this
mixed, and after an elaborate
invention are still shrouded in
hydration step acquire the
mystery. Popular histories focus
necessary plasticity to create
mostly on the colorful characters
shapes of almost arbitrary
and salacious details. Only two
complexity. The objects
scholarly Böttger biographies
are subjected to an initial
exist, the first by Carl August
firing at 850-1000°C which
Engelhardt dating to 1837 (6).
renders them dimensionally
The second was published restable yet absorbent. They
cently by Klaus Hoffmann in 1985 Figure 1. Engraving of Johann Friedrich Böttger are glazed by being dipped into
(7). Hoffmann explicitly makes
aqueous slurry of the starting
the point that there is no body of work that specifically
materials containing a higher proportion of feldspar.
examines Böttger’s chemical activities (8). The purpose
The formation of porcelain occurs during the second
of this paper is to take a first small step in the direction of
heating
to 1450°C. At this temperature feldspar softens
filling in this gap. It is definitely not the author’s intention
and
acts
as flux, forming a eutectic with kaolin and quartz.
to rekindle the centuries-old debate on the relative merits
Upon
cooling,
porcelain forms as a composite. It consists
of the contributions of Böttger vs. Tschirnhaus to the reof a vitreous silica-rich continuous phase with needle
invention of porcelain (see, however, the references cited
like crystals of mullite (9) embedded in it. The continuin the concluding remarks for a synopsis of this debate,
ous phase gives porcelain its translucency; the mullite
particularly those of Pietsch and Ufer).
crystals, because of their exceedingly small thermal
expansion coefficient, provide the resistance to thermal
The Basics of Porcelain Chemistry
shock. Feldspar is not the only substance that can act as a
flux. Calcium sulfate in the form of gypsum was actually
In this section a brief review of the chemistry of porcelain
the flux material used by Böttger in his experiments, as
will be presented. The chemical composition and heat
well as commercially by the Meissen Manufactory durtreatment protocol followed during the manufacturing
ing Böttger’s lifetime. Calcium carbonate and calcium
process give porcelain its unique properties and set it
phosphate behave similarly.
apart from all other ceramic materials. Certain aspects
26
How could anybody come up with these starting
materials and conditions in order to duplicate the manufacturing process of porcelain during the first decade of
the 18th century, when analytical chemistry was virtually
unknown? The contemporaneous primary sources are
silent on this matter. The official biographers speak only
in generalities about Böttger’s diligence, inventiveness,
and methodical approach. There is, however, a remarkably detailed but little known early 19th-century account
that comes from a totally unexpected source.
Simeon Shaw’s Account of the Porcelain
Invention
Simeon Ackroyd Shaw (1785-1859), an author and
schoolmaster, was born in Lancashire, England. He came
to Staffordshire, the center of English pottery manufacturing, to work as a printer for the “Potteries Gazette
and Newcastle under Lyme Advertiser.” In the 1820s
and 1830s Shaw ran a number of academies for young
gentlemen and was the author of several books, among
them “The History of the Staffordshire Potteries,” published in 1829, and “The Chemistry of Pottery,” published
in 1837. “The History of the Staffordshire Potteries” is
one of the earliest chronologically based surveys of the
area’s development from the late medieval period to
the state of the industry in Shaw’s own times. Buried
in the “History” and without any reference to a source
or document lies a surprisingly detailed description of
Böttger’s invention (10):
…While Reaumur was thus employed in France,
Baron De Botticher was equally busily engaged in
Saxony, and first produced the white kind of real
porcelain in Europe. The Baron professed Alchemy, or
the secret of the Philosopher’s Stone, for transmuting
metals into Gold; and having exhibited to his dupes
several specimens, by some means they were shewed
to the King of Poland. To gratify the cupidity of this
monarch, by compulsory divulgement of this secret, an
order was issued for his incarceration in the castle of
Koningstein, where he unremittingly continued making experiments. While pursuing this useless research
without opportunity to destroy or mal-appropriate
whatever was produced, he found in one of his crucibles, what completely answered his purposes; the
intense heat he employed to fuse some of his materials,
rendered the crucibles themselves of similar appearance to the white Chinese porcelain;(very probably
because of accidentally employing some materials in
quality like those used in China;) he carefully repeated
the process, and produced white porcelain; which
caused Dresden to become the seat of the art..
Bull. Hist. Chem., VOLUME 35, Number 1 (2010)
Shaw is just as specific about the location as he is about
the experimental details, Königstein, an impregnable
fortress at the eastern corner of Saxony, about 20 miles
from Dresden (curiously, Shaw uses a quasi-Dutch
spelling, Koningstein). The specification of this location
establishes the time frame, which must coincide with
Böttger’s second incarceration there from September 5,
1706 until September 22, 1707 to prevent his falling into
the hands of the invading Swedish army.
To assess the plausibility of Shaw’s account we
must answer three questions: First, is the transformation
described by Shaw chemically possible? Second, could
it have actually taken place? and Third, is Shaw’s account consistent with the known timeline of other, well
documented events associated with the reinvention of
porcelain? What follows is an examination of all three
questions, albeit in reverse order. A fatal objection could
be raised immediately. It is known that no kilns or ovens
were allowed at Königstein because of the danger of
fire. This well documented fact may have led scholars to
dismiss Shaw’s statement right from the outset, ending
all further discussion. We shall see that this is actually a
spurious objection.
Milestones in the Invention of Porcelain
Europe’s first porcelain manufactory began its operations in 1710 in the castle of Albrechtsburg in the city
of Meissen. Its founding followed Böttger’s famous
Memorandum to the King, dated March 28, 1709, where
he announced that he can produce “good white porcelain
with the appropriate glaze and decoration;” in other
words, a finished, commercializable product. Based
on this document the influential art historian Ernst
Zimmermann in 1909 declared March 28, 1709 as the
official date of Böttger’s invention. Careful reading of
the memorandum actually shows that it is a defensive
document, intended to mollify a Saxon government
growing impatient with Böttger’s failure to deliver on
his promises of transmutation, rather than a triumphant
announcement of success in making porcelain. Nevertheless, Zimmermann’s view prevailed until 1962, when a
page of a laboratory notebook dated January 15, 1708
was discovered in the Meissen archives (11). The document is shown in Fig. 2. A transcript and commentary
were published by Mields in 1967 (12).
The text describes a set of experiments involving
the firing of mixtures of clay from Colditz with alabaster
(calcium sulfate) as the flux. The quality of the ensuing
porcelain for different clay to alabaster ratios is indicated
Bull. Hist. Chem., VOLUME 35, Number 1 (2010)
27
in notes on the margin written in Medieval Latin. The
Experimentation at Königstein?
document appears to be describing a matrix of optimization experiments. Mields attributes the authorship
Tschirnhaus, a mathematician, physicist, and mineraloof the notebook page directly to Böttger because of a
gist, was born in Kieslingswalde (today Sawnikowice
comparison of the handwriting to letters in the Dresin Poland) and died in Dresden. During 1675 he worked
den archives known to be by Böttger’s hand (13). The
with Robert Boyle (1627-1691), Isaac Newton (1643contents of this document
1727), Christiaan Huygens
suggest that the basic for(1629-1695), and was intromulation for porcelain must
duced to Gottfried Wilhelm
have already been known to
Leibniz (1646-1716), with
Böttger and his circle of colwhom he maintained a lifelaborators prior to January,
long scientific correspon1708. This is confirmed by
dence. Besides his contribuPaul Wildenstein (1682tions to mathematics (theory
1744), one of Böttger’s
of polynomials), Tschirnhaus
assistants. Wildenstein deis perhaps best known for his
scribes how, during the last
invention of large parabolic
days of December 1707,
mirrors (1686) and burning
Böttger showed a small
lenses (1687) to create very
unglazed porcelain teapot
high temperatures. In 1687
to Augustus the Strong and
he was able to melt asbestos
demonstrated its resistance
for the first time, a substance
to thermal shock by pulling
regarded since antiquity as
it out of the white-hot oven
infusible. Tschirnhaus was
and throwing it into a pail of
also the first to observe the
cold water (14). More sigphenomenon of eutectic fornificantly, on November 20,
mation. In 1699 he reported
1707 Augustus had already
to the French Academy of
issued a decree assigning
Sciences (16) that, while
Böttger the task of creating
chalk and quartz cannot be
several factories that made use Figure 2. Laboratory notebook page dated January 15, fused at the temperatures availof Saxony’s mineral resources 1708 recording the results from a series of experiments able to his burning mirrors, a
(15). If one rejects Shaw’s ac- with different clay/flux ratios (image courtesy of Staatliche finely ground mixture of the
count, one must conclude that Porzellan-Manufaktur Meissen Historical Collections, two ingredients could be made
reproduced with permission).
the invention of porcelain took
to flow. Based on a written
place in Dresden, after Bötrecord by Leibniz, Tschirnhaus
tger’s return from Königstein, sometime during October/
became interested in porcelain as early as 1675. In 1694
November, 1707. Böttger’s main preoccupation during
he used a burning lens to melt a shard of Chinese porcethose two months was, however, the construction with
lain and showed that metal oxides can be made to adhere
the assistance of Balthasar Görbig (1672-1739) of more
to porcelain at high temperatures. Specifically, he found
efficient ovens for the high-temperature firing of large
that gold under such conditions gives porcelain a purple
porcelain objects. Actual work in ceramic chemistry was
color, an observation he communicated to Leibniz.
left to two of his assistants, Wildenstein and David Köhler
A two-stage burning lens built by Tschirnhaus is
(1683-1723). It is unlikely that Böttger and Tschirnhaus
shown in Fig. 3. It can be seen today at the Physikalischwould have left any work more challenging than the
Mathematischer Salon as part of the Staatliche Kunstsamrefinement of known experimental conditions to their
mlungen, Dresden. The instrument is 2.5 m in height,
assistants. To this end Wildenstein and Köhler used a
and the two lenses are 50 cm and 26 cm in diameter. On
most unusual apparatus, an extraordinary invention of
the basis of Tschirnhaus’ accounts of the substances he
Tschirnhaus. As we shall see, this apparatus resolves the
could bring to a molten state, the highest documented
conundrum of being able to carry out high temperature
temperature is about 1600 °C. The solar energy could be
experiments at Königstein without access to kilns.
28
Bull. Hist. Chem., VOLUME 35, Number 1 (2010)
mixtures of clays and fluxes for porcelain. A less well
known document in the Meissen manufactory archives
and dated to 1743 (19) also refers to experiments with
burning lenses both for the development of red stoneware
(a project that was being run in parallel) and for porcelain.
A passage from the document states that “Tschirnhaus’
burning lenses were used to test not only the red clays,
some of the white clays tested would soften and become
porcelain-like.”
But it is Karl Berling who gives us the most direct
evidence. In the Introduction to the History of the Meissen Manufactory published in 1911 on the occasion of
the 200th anniversary of the Manufactory, Berling states
almost in passing that Böttger used this equipment for
ceramics experiments while in Königstein. He writes
(20):
Figure 3. Two-stage burning lens apparatus built
by Ehrenfried W. v. Tschirnhaus, in Kieslingwalde
around 1690; reproduction (image courtesy of
Staatliche Kunstsammlungen Dresden, MathematischPhysikalischer Salon, Photographer: Michael Lange,
Dresden, reproduced with permission).
focused down to an area of about 10-15 cm2. There is
little doubt that burning lens equipment played a major
role in Böttger’s work. This is hardly surprising, since
Tschirnhaus, the leading Saxon scientist of his time, was
assigned by Augustus in 1704 to supervise Böttger’s experiments closely. The earliest evidence comes from Johann Melchior Steinbrück (1673-1723), who was initially
at Böttger’s private service, and later was charged with
the day-to-day administration (Inspektor) of the Meissen
Porcelain Manufactory. In 1717 he submitted a lengthy
report to Augustus summarizing the events leading to the
founding of the Manufactory in 1710 and its development
in the following seven years under his supervision. In his
report Steinbrück recounts that Tschirnhaus was a proponent of the use of burning lenses in ceramics experiments.
Böttger, in response, raised the curious objection that the
lenses caused melting of the substances that altered their
“essence” (a puzzling concern coming from somebody
attempting transmutation). Nevertheless, Steinbrück
writes, at the end Böttger did make use of such a device
for his invention (17). It is conceivable that the absence
of ovens at Königstein encouraged Böttger to change his
mind. Similarly, Wildenstein complains in his Petition
(18) about how his own eyesight was damaged from the
use of burning lenses when he and Köhler were testing
…and Böttger seems to have been more fortunate than
his master [i.e. Tschirnhaus] in working with the burning glass of the latter. On the Königstein he succeeded
in making Dutch ware, a sort of Delft fayence, and in
the last months of the year 1707 he brought forth in
Dresden red stoneware.
We have so far established that Shaw’s account is consistent with the known timeline of events leading to the
manufacture of commercially viable porcelain, and that
high-temperature experiments on the Königstein even
without the use of ovens were feasible and had in fact
taken place. We shall now turn to the pivotal question
of whether the transformation described by Shaw is
chemically possible.
Crucible Chemistry and Porcelain
The one passage in Shaw’s account that is most important
to the chemical history of porcelain states (10):
…the intense heat he employed to fuse some of his
materials, rendered the crucibles themselves of similar
appearance to the white Chinese porcelain…
The passage describes the observation of an unexpected
event, thus vividly capturing a moment of discovery. To
what extent is this description realistic?
In January, 1702, as Böttger prepared to start his
transmutation experiments for Augustus the Strong,
he gave councilor of mines Gottfried Pabst von Ohain
(1656-1729) a list of chemicals and equipment he would
need for his experiments (21). Included in this list were
Hessian crucibles, a most remarkable type of stoneware, first invented during the late Middle Ages in the
village of Grossalmerode near Kassel in Hessen. These
Bull. Hist. Chem., VOLUME 35, Number 1 (2010)
29
Figure 5. Electron micrograph of mullite needles
from a flux-rich region within a Hessian crucible
(image courtesy of M. Martinón-Torres reproduced
with permission).
Figure 4. Hessian crucibles from ca. 1607-1610 excavated
at Jamestown with evidence of copper smelting, which
may have been used in attempts to produce brass (image
courtesy zof the APVA Image Bank, reproduced with
permission).
thin-walled crucibles are 2-20 cm in height and have an
astonishing resistance to thermal shock. They were the
favorite tools of metallurgists, goldsmiths, assayers, and
of course alchemists the world over. Their characteristic
triangular shape allows for convenient pouring in all
directions. Hessian crucibles have been found across
continental Europe, from Portugal to Norway, and also
in Great Britain and the British colonies of the New
World. The examples of Hessian crucibles shown in Fig.
4 were indeed excavated in the Settlement of Jamestown,
Virginia, the first English speaking settlement in North
America. According to Hudgins (22) they were used by
early settlers for cementation experiments (a step in the
production of brass) around 1607-1610.
The factors behind the heat resistance of Hessian crucibles became clear only very recently through the work
of M. Martinón-Torres, Th. Rehren of the University College London, and I. Freestone of Cardiff University (23,
24, 25). They used scanning electron microscopy and Xray powder diffraction to detect both mullite (see Fig. 5)
and quartz in Hessian crucibles, together with iron oxide.
Just as with porcelain, the resistance of Hessian crucibles
to thermal shock can thus be attributed to the presence of
mullite. By examining the crystal morphology MartinónTorres et al. (24) conclude that most, but not all of the
mullite (26) comes directly from the decomposition of
kaolin during processing at an estimated temperature of
1200-1400°C, rather than through the action of a flux.
All the ingredients for porcelain with the exception of a
sufficient quantity of a flux are therefore present within
the crucible body. Böttger could have indeed transformed
all or part of a crucible into a porcelaineous body in the
manner Shaw describes. He would only need to add a
calcium salt like calcium carbonate or calcium sulfate
(27) under the higher temperatures afforded by a burning
lens apparatus as part of some transmutation experiment.
Calcium salts were commonly found in the alchemist’s
tool kit for purifying and assaying silver or gold by a
process known as cuppelation.
Concluding Remarks
In the light of the evidence presented here, Shaw’s account appears plausible and indeed likely. Böttger could
have gained several key insights from this observation
that later guided his work and that of Tschirnhaus and
their laboratory assistants upon Böttger’s return to
Dresden. Shaw’s account is also consistent with the
archival evidence presented in Ref. 14 and 20, that the
basic formulation of porcelain was known to the team
of Böttger and Tschirnhaus as early as the latter months
of 1707, in contradistinction to opposing claims first
voiced by Bussius in 1719 (28). The observation would
have pointed to the need for higher temperatures. Neither
the small laboratory ovens described by Johann Rudolf
Glauber (1604-1668) nor the larger more efficient ones
by Johann von Löwenstern Kunckel (1630-1703) could
reach the temperatures needed for porcelain production (29). The observation would have also established
Bull. Hist. Chem., VOLUME 35, Number 1 (2010)
30
the flux material. Pabst von Ohain, in notes written on
May 29, 1706 was already speculating that the secret of
Chinese porcelain possibly lay in the use of a calcareous
flux (30).
Most significantly, the observation would have led
Böttger and Tschirnhaus to consider clays with properties similar to those of clay used in the production of
Hessian crucibles. The use of clay from nearby Colditz
for making heat resistant containers and bricks for ovens
that could withstand high temperatures was already well
established. In fact, upon his return from Königstein,
Böttger contended that he knew how to make crucibles
that would surpass the Hessian ones in performance. A
crucible manufactory was one of the several enterprises
he proposed to Augustus. Böttger did bring in Meister
Johann Just Gundeloch, one of the last surviving Hessian crucible manufacturers from Grossalmerode, to
verify his contention. It was ultimately decided not to
build such a factory—based purely on economic considerations (31).
In conclusion, Simeon Shaw’s little noticed passage
is proven plausible and significant in understanding the
process leading to the reinvention of porcelain in 18th century Europe. An important challenge for future research
would be to identify the source for Shaw’s insight.
ACKNOWLEDGMENTS
The author would like to thank Dr. Peter Braun, Director
of Historical Collections, State Porcelain Manufactory
Meissen, for providing a digital copy of the laboratory
notebook page and the permission to publish it; Frau
Yvonne Brandt of the Staatliche Kunstsammlungen
Dresden for her assistance in obtaining a picture of the
burning lens apparatus; and Dr. Carter Hudgins and Ms.
Catherine E. Dean, Curator of Collections APVA Preservation Virginia, for an image of the Hessian crucibles
excavated at Jamestown. Comments by Ian Freestone and
Marcos Martinón-Torres and their permission to publish
electron micrographs of mullite crystals in the crucibles
are gratefully acknowledged.
REFERENCES AND NOTES
* This paper is based on a presentation at the 236th
National Meeting of the American Chemical Society,
Philadelphia, PA, August, 2008, HIST 006.
1.
To appreciate how multifaceted the role of porcelain in
our society is, the reader need only consider that as heat
resistant high voltage insulators, porcelain components
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
are found on virtually every utility pole. At the same
time, a Vienna teapot from ca 1720, made essentially of
the same material, was sold at a recent Sotheby’s auction
well in excess of its pre-auction estimate of $215,000.
For a discussion of protoporcelain ware from the Han
Dynasty see N. Wood, Chinese Glazes: Their Origins,
Chemistry, and Recreation, University of Pennsylvania
Press, Philadelphia, PA, 1999, 21-23.
This attempt to introduce the “essence” or “form” of
porcelain into the clay is entirely within the alchemistic
tradition. For a discussion of the ideas of the alchemists
see F. S. Taylor, The Alchemists: Founders of Modern
Chemistry, Collier Books, New York, 1962, 12-21.
During the 1650s John Dwight (1635-1703) worked for
Robert Boyle, which might explain why he embraced
a chemical rather than alchemistic approach. He was
granted a patent on April 17, 1672 for making “transparent Earthen Ware” which, nevertheless did not rise to the
level of true hard paste porcelain. Dwight’s move away
from the use of glass frit is pointed out by Honey; see: W.
B. Honey, Dresden China, Tudor Publishing Company,
New York, 1946, 7.
Augustus the Strong (1670-1733), Prince Elector of
Saxony (r. 1694-1733) and King of Poland (r. 1697-1704
and again 1709-1733).
C. A. Engelhardt, J. F. Böttger, Erfinder des Sächsischen
Porzellans, Verlag von Johann Ambrosius Barth, Leipzig,
1837, (reprinted by the Zentralantiquariat der Deutschen
Demokratischen Republik, Leipzig, 1981).
K. Hoffmann, Johann Friedrich Böttger: Vom Alchemistengold zum weiβen Porzellan, Verlag Neues Leben,
Berlin, 1985.
Eine detaillierte Darstellung der chemischen Experimentiertätigkeit Böttgers muβ jedoch einer Spezialstudie vorbehalten bleiben.“ (A detailed presentation of Böttger’s
experimental work must be left to [a future] specialized
research on the subject); Ref. 7, p 187
Mullite has the nominal composition 3Al2O3.2SiO2 and
is the only chemically stable intermediate phase in the
SiO2-Al2O3 system. Its high temperature strength and
resistance to thermal shock and chemical attack make
mullite one of the most versatile engineering ceramics.
S. Shaw, History of the Staffordshire Potteries, Praeger
Publishers, (reprint of the1829 ed.), New York, 1970,
196.
Staatliche Porzellan-Manufaktur Meissen, Historische
Sammlungen P 44 Blatt 1.
M. Mields, “Eine Versuchsaufzeichnung von Johann
Friedrich Böttger zur Porzellanerfindung aus dem Jahr
1708,” Ber. Dtsch. Keram. Ges., 1967, 44, 513-517. A
transcript and English translation of the document in
pdf-format are available from the present author upon
request.
An alternate view holds that the document is by the hand
of Dr. med. Johann Jakob Bartholomaei (1670-1742),
Böttger’s personal physician, who on January 6, 1708
was also assigned to help him with his ceramics work.
Bull. Hist. Chem., VOLUME 35, Number 1 (2010)
14.
15.
16.
17.
18.
19.
20.
21.
Regardless of who wrote the document, it pushes the date
of the actual invention to the previous year.
Wildenstein gives a colorful account of this demonstration 29 years after the fact in his lengthy 1736 petition for
payment of salary owed to him by the Meissen Manufactory. A transcript of the text with commentary has been
published by Walcha: O. Walcha, “Paul Wildensteins
Eingabe,” Mitteilungsblatt Keramik-Freunde d. Schweiz,
1958, 42, 17-22. The author would like to thank Dr. Pierre
Beller, treasurer of the Keramik-Freunde der Schweiz,
for a copy of the article. In a memorializing letter to Augustus immediately following the demonstration, Böttger
states that the teapot was made with the help of Herrn
von Zschirnhausen [sic] („mit Bey Hülffe des Herrn von
Zschirnhausen“ fertiggestellt wurde). The source for this
quote is a document in Staatsarchiv Dresden, Geheimes
Kabinett, Loc. 1340: J.F. Böttgers u. Consorten Angelegenheiten, Vol. II, fol. 148. I would like to thank Dr. Mathias Ullmann, Chairman of the Tschirnhaus-Gesellschaft
Dresden for communicating the archival location of the
document. Böttger’s statement shows that the relationship
between Böttger and Tschirnhaus was one of collegiality
and sharing of information.
The full text of the decree is given in Ref. 6, p 255. The
text does not explicitly enumerate the projects and uses
instead the phrase “tasks known only to us” (Uns allein
bekannte Verrichtungen). They are discussed explicitly
in the Steinbrück Report of 1717 (see Ref. 17 below).
On July 22, 1682, at the age of 31, Tschirnhaus became
the first German national to be elected to the French Royal
Academy.
I. Menzhausen, Johann Melchior Steinbrück Bericht über
die Porzellanmanufaktur Meissen von den Anfängen bis
zum Jahre 1717; Kommentar, Transkription und Glossar,
Edition Leipzig, Leipzig, 1982, 47-48.
Ref. 14, p 21.
Ref. 7, p 375. Dr. med. Christoph Heinrich Petzsch (16921756), the presumed author of the document, uses vivid
Latin prose to describe the outcome of these porcelain experiments: “…semidiaphanam tremuli narcissuli, ideam
lacteam” or “appearing milky white like a translucent
fluttering narcissus.”
K. Berling, Ed., Meissen China, Dover Publications,
Inc., New York, (unabridged reprint of the work originally published in English in 1910 under the title Festive
Publication to Commemorate the 200th Jubilee of the
Oldest European China Factory, Meissen, by the Royal
Porcelain Manufactory, Meissen), 1972, 2. It should also
be mentioned that while in Königstein, Böttger received
several visits from Tschirnhaus. Following the visit by
Tschirnhaus, Nehmitz, and Ohain at the end of June 1707,
Böttger memorialized “mit dem Herrn von Schürnhausen
[sic] alle Veranstaltungen verabredet zu einer sehr fleißigen Arbeith.“ (I have agreed with Tschirnhaus upon all
arrangements for a very diligent work[plan]).
The list is discussed in Ref. 7, pp 188-189 (page numbers
refer to the actual report, not the transcript).
31
22. C. C. Hudgins, “Chemistry in the New World,” Chem.
Heritage, 2007, 25, 20-26.
23. M. Martinón-Torres, T. Rehren, and I. C. Freestone, “Mullite and the Mystery of Hessian Wares,” Nature, 2006,
444, 437-438.
24. M. Martinón-Torres, I. C. Freestone, A. Hunt, and T.
Rehren, “Mass-Produced Mullite Crucibles in Medieval
Europe: Manufacture and Material Properties,” J. Am.
Ceram. Soc., 2008, 91, 2071–2074.
25. M. Martinón-Torres and T. Rehren, “Post-Medieval Crucible Production and Distribution: A Study of Materials
and Materialities.” Archaeometry, 2009, 51, 49-74.
26. Martinón-Torres et al. did observe highly elongated mullite crystals in areas of locally high feldspar concentration.
These are the crystals shown in Fig. 5.
27. The reader is reminded that calcium sulfate in the form
of gypsum was the typical flux used in early Böttger
porcelain.
28. On January 19, 1719, less than two months before Böttger’s death, Caspar Gottlob Bussius, treasurer of the
Meissen Manufactory, claimed in a report to the Manufactory Commission (roughly equivalent to today’s board
of directors) that the credit for the invention of porcelain
should properly go to Tschirnhaus and that following
Tschirnhaus’ death the secret of the porcelain composition
(the Arcanum) was illicitly given to Böttger by Steinbrück,
who was at the time the private tutor of Tschirnhaus’
children. Dismissed at the time, the story was revived
during the early 1900s by Curt Reinhardt and Hermann
Peters (see for example: C. Reinhardt, “Tschirnhaus oder
Böttger? Eine urkundliche Geschichte der Erfindung des
Meißner Porzellans,“ Neues Lausitzisches Magazin, 1912,
88, 1-162; and also P. Diergart, “Was wissen wir gegenwärtig von der Erfindungsgeschichte des europäischen
Porzellans? Mit Benutzung eines Manuskriptes des Herrn
Hermann Peters-Hannover,” Mitteilungen zur Geschichte
der Medizin und der Naturwissenschaften, 1906, 5, 534536. The date of the laboratory notebook page shown in
Fig. 2 and the account given in the Wildenstein Petition
(see Ref. 14) show that Böttger, Tschirnhaus, and their
assistants already knew the recipe for porcelain during
the second half of 1707, about a year before Tschirnhaus’
death. The timeline for Bussius’ conspiratorial hypothesis
is therefore wrong but has nevertheless been repeated as
recently as 1998 (see e.g., M. Schönfeld, “Was There a
Western Inventor of Porcelain?” Technol. Cult., 1998, 39,
716–729). A counterpoint is offered by Ulrich Pietsch,
the director of the Dresden Porcelain Collection: U.
Pietsch, “Tschirnhaus und das europäische Porzellan,”
in P. Plassmeyer and S. Siebel, Ed., Ehrenfried Walther
von Tschirnhaus (1651–1708): Experimente mit dem
Sonnenfeuer, Staatliche Kunstsammlungen, Dresden,
2001, 68-74. For a more up-to-date account see also U.
Pietsch and P. Ufer, Mythos Meißen, edition Sächsische
Zeitung, Dresden, 2008.
29. Alchemists and early chemists typically built the ovens
used in their experiments themselves. A new design to
Bull. Hist. Chem., VOLUME 35, Number 1 (2010)
32
improve oven efficiency was published by Glauber under
the name Furni novi philosophici (first edition, in German,
1646-49). Further improvements in oven construction
were made by Kunckel as reported to Prince Elector
Johann Georg II in 1675 (see Ref. 7, p 260). None of
these designs could produce the temperatures needed for
porcelain production. This explains Böttger’s preoccupation with oven design during October/November, 1707.
30. Ref. 7, p 219.
31. Ref. 17, pp 76-79.
ABOUT THE AUTHOR
Dr. Nicholas Zumbulyadis obtained his Diploma in
Chemistry in 1971 from the Technical University of
Darmstadt, Germany and his Ph.D. in physical chemistry
from Columbia University in 1974. In March, 1976 he
joined the Eastman Kodak Research Laboratories, where
he worked until his retirement in June, 2005. He is the
author of over 55 papers in solid state nuclear magnetic
resonance as well as several patents. Zumbulyadis is also
a collector of 18th-century European porcelain and the
author of the book Meissen’s Blue and White Porcelain,
Schiffer Publ. Ltd., Atglen, PA, 2006, as well as related
talks and articles published in art historical journals. His
current research focuses on the history of cobalt blue
pigments from the twin perspectives of the chemist and
art historian.
Division of the History of Chemistry
of the
American Chemical Society
Citation for Chemical Breakthroughs
Call for Nominations
The Division of History of Chemistry (HIST) of the American Chemical Society solicits nominations for one
of its award programs, Citation for Chemical Breakthroughs. This award recognizes breakthrough publications, books and patents worldwide in the field of chemistry that have been revolutionary in concept, broad in
scope, and long-term in impact. The award consists of a plaque that will be placed near the office or laboratory
where the breakthrough was achieved. Up to 10 awards will be presented annually. Nominations consist of
a full literature citation and a short (200 word maximum) supporting statement. All nominations must be
received by April 1, 2010. Selections will be determined by a panel of distinguished chemical historians and
scientists. Further information can be found on the HIST website under the heading “Divisional Awards”:
http://www.scs.uiuc.edu/~mainzv/HIST/ Submit nominations or questions to: hist_ccb@yahoo.com.
~~ .. P Photocopy Request from Ma, William
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Subject: RLCPPhotocopy Request from Ma, William
From: rlcp-copy-request@stanford.edu
Date: 5/7/2015 12:25 AM
To: cooperative@stanford.edu
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RLCP Photocopy Request
Program Card Number — 15114295
Department — History of Art
Patron — Ma, William
Institution — UC Berkeley
E-mail–williamh.ma@gmaiLcom
Telephone -Title — Ceramics and Civilization, vel 1: Ancient Technology to Modern Science
Publisher — American Ceramic Society
Volume, Number — 1
Date, Year — 1985
Pages — 135-162
Author — Li, Jiazhi
Q.”f.”,.L
Title of articl~- “The Evolution of Chinese Pottery ,and Porcelain”
Call number TP791 .A44 1984
Not needed a ~ -Holding Institution — Stanford
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THE EVOLUTION OF CHINESE POTTERY AND
PORCELAINTECHNOLOGY
Li Jiazhi”
Shanghai Institute of Ceramics
Academia Sinica
Shanghai, China
Over a period of 8000 years in China, there was a gradual evolution of
raw material selection and refining, in kiln design and firing temperatures, and in glaze formulations. Chemical analyses and microstructure
evaluation are reported, making it possible to follow the course of this
process. Each of these developments was required in order for porcelain to have been invented and perfected in China.
Chinese ceramic technology has a very long history. As far back as the
Neolithic age (10,000-4000 years ago), beautiful red, gray, black, and
painted pottery was made. Very high standards
were achieved in the selection of raw materials and in forming, decorating,
and firing techniques.
Later, there were breakthroughs
in the selection and refining of raterials;
improvements in kilns, thus raising firing temperatures;
and breakthroughs in the discovery and application
of glazes. Protoporcelain
was
made beginning about 3000 years ago in the Shang and Zhou dynasties.
After a transition stage, the protoporcelain
technology
matured.
By the
Eastern Han dynasty, the transition
from pottery to porcelain was complete, making China the first nation to produce porcelain.
Based on an analysis of the development
of Chinese ceramic technology, three major stages and three major advances in the evolution of porcelain from pottery are proposed.
The major stages are (I) pottery, (2)
protoporcelain (a transition stage), and (3) porcelain. The major advances
are (I) the selection and refinement of raw materials, (2) the improvement
of kilns and increase in firing temperatures,
and (3) the discovery and development of glazes. The development
of these three advances basically
describes the evolution of Chinese ceramic technology.
Selection and Refin~ment of Raw Materials
Table I shows the chemical compositions
of about 80 pottery, protoporcelain, and porcelain bodies, beginning with the Neolithic
period.
Figure I shows the evolution of these compositions
with time (not all of
the data in Table I are included in the figure). Silica and alumina are the
main constituents of the bodies; Fe,O” TiO” CaO, MgO, K,O, Na,O,
and MnO are included in the formula R,Oy. The R,O,. oxides act as a
flux and have a concentration
lower than 10%. This classification
IS more
reasonable than that which conventionally
combines
Fe,O, and Ti02
with AI,O, and SiO,. It also shows larger differences
between different
points in time on the composition
distribution
diagram. I
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Li. Susan Rosevear.
and W. David
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With a few exceptions, all Neolithic and Shang pottery compositions
are located in the upper part of Fig. I; the compositions of Shang-Zhou
proto porcelain down to Ming-Ching porcelain are located in the lower
part. From the upper right, extending to the lower left of the figure, an increasingly larger area is formed. This change is due to increased AI,OJ
content and the decreased flux content (Fe,03, CaO, and MgO) and is
related to the selection and refining of raw materials.
Judging from the composition and appearance of the Neolithic pottery, apparently the raw materials for making pottery were not randomly
selected by the ancient Chinese. Although they could not go far to find
raw materials, they did select with purpose and good sense. They selected mainly red, black, and brown soil,’ and they knew how to wash
away sand particles, lime, and grass roots. If not, the red, gray.iand black
pottery would not look so smooth, the fracture surface would not be so
uniform, and the shape would not be so regular. The ancient Chinese
2.6
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Proto-porcelain
0- Porcelain
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bodies with time.
From NeoLithic through Shang-Zhou , even to the Qhin and Han dynasties, all ceramic bodies have Fe,O, concentrations around 6% (except for
the “hard pottery,” Sh 5; the striped pottery, Sh 6; and the early Hamudu painted pottery, YMT). The Fe,O, content decreases to below 3% In
protoporcelain. In the Tang, Song, Yuan, Ming, and Ching dynasty porcelain, the Fe,O, content is about I%. Thus, the decreased Fe,O, content
was critical for improving the quality of porcelain.
The Improvement of Kilns and Increase of Firing Temperature
Improvement in pottery quality and the transition to porcelain are
closely related to the increase in firing temperature, which was made possible by the improvement of kilns.
.
The firing temperatures of the Neolithic and the Shang pottery were
below 1000°C, normally around 950°C. By the Shang-Zhou dynasties.
the firing temperature had been increased to about 1200°C. The Shang143
,
Zhou Jiangshan prQtoporcelain had a firing temperature of about 1200’C;
some even reached I250’C. 3 The Shang Zhengzhou hard pottery and
the Eastern Zhou Houma Shanxi protoporcelain had firing temperatures
of 1180′ and 1230’C, respectively. In the Han, Jin, Sui, Tang, and later dynasties, the temperatures reached = 1300’C. For example, the Eastern Han,
Shangyu Yue ware green porcelain had a firing temperatures of 1310’C’
The Tang, Chaung, ware and Henan, Kongxian, white porcelain had a
firing temperature of 1300′ to 1350′ C.5 The increase of firing temperature
with time is shown in Fig. 3.
1400
1300
I
1200
1100
~ 1000
f-
900
BOO
700
600
HXI YMTI
Fig. 3. Change
DWQI
LZhl Shl
YMTl2
LSh6
in firing temperatures
QI
of Chinese
Zh9 Zh2 Zh3 Zh7
ceramics
H2
H5
J4 HG5 HN5 CI3 Cl4
with time.
Archeological studies show that most Neolithic kilns were the horizontal cave type. Figure 4 shows a horizontal cave kiln of the Yang-shao
penod at Shihen Shaanxi, and Fig. 5 shows a horizontal cave-type kiln
of .the Lungshan penod at Shanxian, Henan. Although the Lungshanpel lad kiln IS more advanced than the Yanshao-period kiln, the name
Fig. 4. Yangshao
horizontal
cave-type
kiln at Benpo,
144
Shihen,
Shansi.
I,
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soil
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Flame
passage
FOO’?
entry
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Crees section
,,-O~~.::50::c:::m::.-_-.:.’m
Fig. 5. Longshan horizontal cave-type kiln at
Mioudikou, Shaanxiau, Henan,
can pass through the tunnel and firing chamber freely, which is disadvantageous for raising the temperature. Therefore, the firing temperature
in these kilns was generaIly below 1000″C. In the Shang dynasty, protoporcelain with a firing temperature over 1200″C appeared in both southern and northern China. It was very difficult for the Neolithic kiln to
reach such a high temperature. Archeologists have not found kilns that
have large structural differences for that period.
Figure 6 shows an example of a kiln of the middle Shang period at
Zhengzhou, Henan. It was not until the Warring States period that kilns
with chimneys, such as the kilns found in Jianglinxian, Hubei (Fig. 7)
and Shaoshanxian, Chekiang (Fig. 8), were constructed. Chimneys are
characteristicaIly located at the rear of the kiln. In addition, dragon kilns
were found in the southern part of China (e.g., at Shaoxing, Chekiang,
and Zhenchen, Guangdong). Not all of those excavated kiln tops were
preserved, and it would be impossible to preserve the chimneys if they
145
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r
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wall
~
soil
Raw
,
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Fig. 9. East Han dragon kiln at Shagyu, Chekiang.
147
technology. The improvements in kiln design guaranteed an increase in
firing temperatures from below 1000″ to higher than 1300″Cand provided
the necessary conditions for development of Chinese ceramic technology.
Discovery and Improvement
of Glazes
It is believed that Chinese glazes first appeared in the Shang-Zhou
period about 3000 years ago. Although still very primitive, they all possessed transparent,
glossy, and impermeable
characteristics. Thus,
glazes were invented before the Shang dynasty, and there should be
some rule for the evolution of Chinese glazes.
The first Chinese porcelain was made at Chekiang.” A large quantity
of proto porcelain had been made there during the Shang dynasty] and
was the basis for the formation of glazes in Chekiang. Recently, preShang glazed black pottery” was found in graves located in the southern
area of Jiangshanxian, Chekiang. Neolithic painted pottery with a white
painted layer on the surface (archeologists call it white-coated) has been
found in Hemudu, Yuyaoxian.” These new finds provide us with knowledge of the embryo period in glaze developments.
The chemical compositions of about 100 samples of Neolithic painted pottery, white-coated, and recent porcelain glazes (Tables II and Ill),
show the evolution of Chinese glazes. In addition to SiO, and Al,O] in
the glazes, there are RO(CaO + MgO), R,O(K,O + Na,O), and Fe,O]
introduced as the flux. In China, RO could come from limestone, plant
ashes, or Ca-containing clay. The Fe,03 and TiO, were probably introduced from the clay, as were the alkalies; Fe,O] and TiO, act as both
fluxes « I0%) and as coloring agents. As time passed, the concentrations of
flux in the glaze, especially RO, showed noticeable and regular variations
(Figs. 10 and II). Based on these regular variations, we can divide the evolution of Chinese glazes into four stages corresponding to four historical
periods.
Pre-Shang
Period: The Embryo
Stage of Glazes
This period ranges from 1600 8.C. to the Neolithic age. Archeological
excavations have not uncovered any protoporcelain or glazed pottery of
this period with a transparent, glossy, and impermeable glaze.
Ancient potters tried many methods to overcome the problems of
surface roughness, water absorption, and contamination of pottery. After
many years of practice, they finally created glazes.
Painted pottery was made by first applying a white coating on the
red or black pottery, then painting with red and black colors (Fig. 12).
The. white coatings of painted pottery from Hemudu, Chekiang; Dadunzi.Tiangsu; and Dahecun, Henan all contain = 10% flux. However, since the
finng temperature was only = 1000″C, it was not possible to melt the coating
and convert It into a glaze. The microstructure in Fig. 13 shows only a
small amount of glassy phase and large amounts of mica and quartz
particles 10 the white coating. The composition is similar to that of the
body, but the particle sizes are finer. Therefore, the white coating is
composed of clay with particle sizes smaller than that of the body. The
black pamt has a higher content of glassy phase with some iron precipitates because of Its high Fe,O] content and the oxidizing firing atmosphere.
148
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Fig. 11. Change of flux and coloring agent. constituents in the c?alings
and glazes of Chinese pottery and porcelain. (1) Pre-Shang pertoo, (2)
Shang-Zhou period, (3) Han to Five Dynasties period. (4) Song dynasty
to recent years.
157
Fig. 12. Neolithic, Dedunzf. Jiangsu painted pottery.
Fig. 13. Microstructure of the pottery body, white coating, and black paint of
the Neolithic, Dadunzi, Jiangsu painted pottery (perpendicular polarized
tight, x 250).
The clay glaze of the Pre-Shang J iangshan, Chekiang black pottery
dark, rough, and permeable. Although there are higher amounts of
glassy phase, there are also many bubbles, quartz remnants, many iron
precipitates, and many small particulate substances (Fig. 14). The composition has a low alkali content, about 5%. The total concentration of the
flux is higher than that of the painted pottery white coating, but generally the flux concentration is no more than 15%. The firing temperature had
reached = IIOO’C, but this was not high enough to obtain a glossy, transparent, impermeable glaze.
IS
158
F.lg. 14. Microstructure of the black clay glaze Zh J1 (4) of the Pre-Shanq
~Iangshan, Chekiang clay glazed black pottery (perpendicular polarized
hght, x 100).
Thus, because of insufficient quantities of flux and low firing temperatures, the pre-Shang white coating and the black clay glaze do not possess the properties of a glaze-although
they do have the form of glaze.
This is the embryo stage of glazes.
Shang-Zhou Period: The Formative
Stage of Glazes
From 1600 B.C. in the Shang dynasty to 220 B.C. in the Zhou dynasty,
protoporcelain appeared, and the pottery-porcelain transition occurred.
The discovery and development of glazes is one of the three major advances in ceramic technology.’ The glaze that appeared in this period is
generally thin, has small cracks, and is light brown or gray-green. It is
transparent but has a few small bubbles and poor body-glaze bonding,
is easy to peel off, and possesses a certain primitive style (Fig. 15). The
concentration of flux increased to =20%; the RO content increased from

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