Authors: Janet Gleeson
Activities at the laboratory were to be strictly confidential. There was to be no discussion of the work with outsiders, no
unauthorized persons were allowed in the castle's confines and the windows were bricked up so that no casual onlookers could
gather an inkling of what was going on. Twenty-four furnaces were built for Böttger's use, and on the king's special order
every clay pit in the land was ordered to deliver sixty-five-pound samples of earth to the castle laboratory to be tested.
Böttger and his assistants—who were treated as little better than prisoners though they had committed no crime—were locked
into the laboratory to work in tandem on the development of gold and porcelain.
Reluctant though he was to give up his obsessive quest for the arcanum for gold-making, Böttger reasoned that any breakthrough
discovery he made with regard to ceramics would buy him time from the king. Gold remained uppermost in his mind, but porcelain
provided an additional challenge, a way of proving once and for all that he was not a fraud. It was a test that, to his own
surprise, he found increasingly compelling.
As the weeks passed, Böttger followed a course of steady and careful analysis of the properties of the minerals and clays
at his disposal. Tschirnhaus was a regular visitor, monitoring progress and sharing with Böttger the findings of his own research.
Tschirnhaus had already succeeded in producing small beads of a ceramic material that he considered to be porcelain, although
in fact it was probably no more than what is now termed opaque or milk glass, and he had made an artificial hard stone resembling
agate.
One of the fundamental differences between the ceramics such as faience, stoneware and soft paste porcelain that were already
made in Europe and the true hard paste porcelain that Böttger sought was the temperature at which the latter was fired. Faience
or delft-ware, the most popular type of European earthenware pottery, needed only to be fired at a relatively low temperature
and the porous body required a glaze to make it watertight. But Böttger knew that the fineness and brilliance of true porcelain
would never be rivaled by such crude earthenwares. Stoneware, made in Germany since medieval times, needed firing at a temperature
of 1200–1400° C to vitrify the clay. But here too the resulting material, although nonporous, was not translucent and lacked
the refinement of porcelain.
From his travels in France Tschirnhaus had also probably learned how to produce soft paste porcelain, which uses glass ingredients
fused with clay at a temperature of 1100° C to achieve a nonporous body. He also knew that despite the charms of soft paste
it had many drawbacks. It was prone to collapse in the kiln, granular in texture, and lacked the crystalline hardness of Oriental
porcelain. The formula
for pâte tendre,
both Böttger and Tschirnhaus realized, was not the arcanum for which they searched.
Already familiar with glassmaking processes from his friendship in Berlin with the glassmaker Johann Kunckel, and well versed
in the effects of heat on minerals from his gold-making pursuits, Böttger seems to have realized from Tschirnhaus's experiments
that firing at temperatures far higher than those used elsewhere was a key element necessary to change the clay into a vitrified
glassy body. In this sense he approached the problem of porcelain-making both as a “modern” scientist and as a medieval alchemist.
In order to achieve the nonporous vitrified quality of true porcelain you did not need glass, he reasoned, but to melt rock
to transmute it into an entirely different form, in the same way, he believed, as lead could transmute into gold. But to discover
the necessary ingredients you needed the systematic experimental approach of modern science.
Characteristically confident in his own ability to solve a problem no one else could fathom, he chose with intuitive brilliance
to follow a totally different route from all the earlier would-be porcelain-makers. Ignoring porcelain's superficial similarities
to glass, he embarked on a series of carefully conducted experiments in which he mixed various combinations of the clays and
rocks available and fired them at temperatures far higher than had ever been attempted before.
A year after his arrival at Meissen, Böttger, still deeply involved in systematically testing the materials available to him,
succeeded in making small sample slabs of a fine red stoneware, a completely new ceramic material. Vitrified and hard as rock,
this richly colored brick-red material was far finer in texture than the stoneware produced in other German potteries, and
resembled closely a material made in the Yixing region of China, but it was not translucent and it was not porcelain.
Before he had time to develop this red substance more fully or even to fashion and fire it into anything other than a test
slab, political events irrevocably interrupted progress.
Tschirnhaus arrived unexpectedly from Dresden accompanied by Prince von Fürstenberg's bailiff. He brought worrying news: the
war with Sweden was proving even more disastrous than anyone had feared. Charles XII of Sweden had triumphed over Augustus
in Poland and was now marching through Saxony and advancing on Dresden. The king, though fraught with anguish, was not too
preoccupied to be able to spare a thought for the safety of his most valued possessions. His manuscripts, jewels and precious
works of art were all to be sent to Saxony's most impregnable fortress, Königstein.
After more than four years of captivity Böttger had produced little of any value, but Augustus still considered him an immensely
important possession on a par with his gold and his jewels, and he too therefore needed safeguarding. The Swedish king was
known to share Augustus's fascination with alchemy. He had spared the life of one of his generals by the name of Paykhull,
who had been convicted of treason and sentenced to death, because he had promised to make alchemically a million crowns of
gold. If Böttger were left at Meissen and fell into enemy hands, it was almost certain that Charles would seize him and force
him to work for the Swedish cause. To avoid such a disastrous eventuality it was imperative that Böttger be taken to Königstein.
In the meantime the laboratory would have to be closed and those assistants not accompanying the alchemist (only three were
permitted to attend him) must make their own arrangements to avoid capture. With little time to spare, Böttger's chosen companions
packed a handful of their master's belongings and the precious notebooks which he refused absolutely to leave behind and prepared
for the unexpected journey. The hard-won fruits of the last year's labor, the successful samples, the laboratory equipment
and all their other personal possessions were to be sealed up in two secret rooms in the Albrechtsburg. No one knew if they
would ever be seen again or when work might be resumed.
To Böttger this sudden change in circumstance seemed catastrophic. He already felt within sight of the arcanum for porcelain,
and the prospect of an indefinite delay coupled with the thought of a renewed period of imprisonment at Königstein must have
aroused feelings of profound unease. There was no possibility, however, that a direct order of Augustus the Strong could be
overruled, and soon after the arrival of Tschirnhaus and his party, Böttger and three assistants were bundled into a waiting
carriage and given a military escort to their bleak prison. The others went to Freiberg and waited.
Even in this remote and impregnable place Böttger's presence was treated with obsessive secrecy. As a precaution against his
falling into enemy's hands his little party was identified in the castle's records only as an anonymous “gentlemen” and three
servants—whose duties included ensuring that he spoke to none of the castle's other occupants.
For the indefatigable young Böttger, the next year seemed interminable. There were no laboratory facilities and no substitute
occupation with which to pass the endless days and nights; even books, paper and ink were denied him. As the months crept
by, conditions improved only marginally. Driven almost mad by the enforced inertia Böttger managed, with his usual ingenuity,
to find a way of having limited contact with some of the castle's other involuntary residents—the vigilance of his guards
was no match for the determination of Böttger when challenged. The other prisoners—mainly political detainees—feared for their
lives and were frantic to find a way to escape.
Unable to resist the temptation of positive action after months of boredom, Böttger joined the conspiracy and helped plan
a breakout—this was a field in which he was doubtless regarded as something of an expert. But at the final moment, perhaps
remembering his promise to the king and fearing the consequences of angering him further, he dropped out of the attempt.
From then on the emotionally fragile Böttger descended into increasingly severe depression, emerging from bouts of despair
only to write frantic letters to the king—having finally been granted the luxury of paper and ink—pleading for his release
and begging to be allowed to resume his work. As he waited helplessly for Augustus's response to bring this purgatory to an
end his penchant for wine probably gained further hold, providing temporary respite from the misery of incarceration.
A year after Böttger had been brought to Königstein the political turmoil in which Saxony had become embroiled was resolved,
temporarily at least. Augustus had been forced to abdicate as King of Poland and the Swedes withdrew from Saxony. As soon
as the situation in Dresden became more settled Augustus's mind turned once again to gold and porcelain. With Poland lost,
Augustus had little need now to absent himself from the city, but the war had been costly and money was needed more urgently
than ever. As far as he was concerned, Böttger was now going to prove his worth.
In the meantime the despairing Böttger's letters to the king begging him “in the name of heaven” to give him an audience included
a new promise: “It is my great hope, that with the help of Herr von Tschirnhaus, I can within two months present something
great.” Augustus's appetite was immediately whetted and he summoned the alchemist to be brought to Dresden for a secret meeting.
At five in the morning on June 8, 1707, Böttger met the king and elaborated on his plans. He was positive that, given the
right equipment, he would quickly make a breakthrough and find the arcanum for porcelain—and porcelain would be as effective
as gold in solving the king's financial problems.
Augustus was easily convinced. While Böttger returned temporarily to Königstein he gave orders for a new laboratory to be
prepared, this time not in Meissen but in Dresden, where he could keep a close eye on developments. Three months later the
preparations were well under way and Böttger, finally recalled from Königstein, visited his new prison for the first time.
The laboratory was constructed in the Jungfernbastei, the Maiden's Bastion, in the dank maze of malodorous vaulted fortifications
bordering the Elbe beneath the eastern city walls. Mere mention of the name Maiden's Bastion was enough to strike fear in
the hearts of Dresden citizens, for it was said that the place was so called because one of the gloomy cavernous tunnels contained
a bizarre machine in the form of a steel woman with rotating arms of razor-sharp swords. Those who fell from favor in the
court were forced to walk blindfolded toward the machine until they were sliced to shreds and a trapdoor in the floor opened
allowing the kill twitching body to sink without a trace into the river Elbe.
Despite the fearsome surroundings, the move to Dresden and the chance to resume his work came as a profound relief. Böttger
knew that once again his life was on the line, but work would bring respite from the monotonous tedium of the last year and
he was confident of rapid progress.
A new kiln, larger and capable of higher temperatures than those at the Albrechtsburg, had yet to be constructed. In the meantime
he resumed research using Tschirnhaus's burning glasses. The glare reflected by these massive lenses was so intense that many
of those involved in the experiments irreparably damaged their eyesight. Böttger's assistant Wildenstein wrote later, “Köhler
and I had to stand nearly every day by the large burning glass to test the minerals. There I ruined my eyes, so that I now
can perceive very little at a distance.”
Soon after Böttger's new laboratory was more or less functional the king paid him a visit. Gold was still an overriding priority,
he said, and this time he would not listen to any excuses: failure would cost Böttger his life.
Bearing in mind the king's interest in porcelain, Böttger decided that his chances of once again cheating death would be improved
if he ignored these threats and concentrated on ceramics rather than gold. Within a few weeks his experiments succeeded in
producing again the red stoneware and he began making inroads into white porcelain production, rigorously testing combinations
of clays and minerals fired at varying temperatures for various lengths of time. More materials were urgently needed, and
Böttger was exceptionally given permission for some of the assistants to leave the prison temporarily in order to collect
them.
The component on which Böttger soon focused was kaolin, or china clay, a fine grayish earth that had been acquired from a
mine in Colditz but which takes its name from the Chinese word
kao-ling,
denoting the high mountains where the Chinese deposits of clay were found. Kaolin is termed by geologists a decomposed feldspathic
product; it is the substance that results when granite has decayed after being subjected to the prolonged effects of weathering.
The clay's principal component is kaolinite, a hydrated aluminum silicate that consists of numerous microscopic flakes that
can move against one another and gives the clay its plasticity, making it ideal for modeling. The other factor that made kaolin
attractive was that when fired at high temperature it turned pure white—a key characteristic of Oriental porcelain.
But while kaolin softens at high temperature it does not melt. Thus it cannot alone create the translucent, pure white, nonporous
body that defines Oriental porcelain. Another fusible substance to fill in the pores of the clay and give the body its glassy
quality was clearly needed. Among the minerals Böttger tried mixing with the clay were various types of alabaster, a calcareous
material. Tests were encouraging; alabaster from Nordhausen, Böttger found, responded especially favorably.