The secretive world of the alchemist has been revealed by the first scientific analysis of a 16th-century laboratory.
Dozens of pieces of equipment used in the quest for the philosopher's stone are being tested at University College London's Institute of Archaeology to determine how they were made and how they were used.
Preliminary results from X-ray fluorescence analysis and scanning electron microscopy, published in Antiquity , show an unsuspected level of sophistication in the work undertaken by the forefathers of modern chemists.
Marcos Martinón-Torres, who is leading the project with Thilo Rehren, professor of archaeological materials and technologies, said: "We have taken the 16th-century laboratory to the 21st-century lab to get a privileged view into the experiments carried out in the Renaissance.
"The history of alchemy and chemistry will now have to be rewritten, and archaeologists and historians will have to work hand in hand to this end."
Some 800 pieces of equipment were found by Dr Martinón-Torres' colleague Sigrid von Osten in 1980 beneath a church in Oberstockstall, Austria. They had been deliberately buried at the end of the 16th century after an earthquake. Among them were triangular crucibles, alembics and other pieces of glass and ceramic apparatus.
Alchemy was previously known from writings that were often cloaked in confusing symbolism and allegory and sometimes written in code. Physical remains were meagre. As a result, the alchemist has been depicted as more of a fantasy-chasing mystic who wanted to turn base metals into gold than a serious researcher.
Dr Martinón-Torres said analysis of the Oberstockstall find suggested otherwise. He said the equipment was of a high technical standard, while its use exhibited a knowledge of scientific principles such as constant combining proportions, conservation of mass and the behaviour of different elements and compounds under high temperatures.
"Therefore, [the alchemist] was not a charlatan or a fabulous conjurer, but rather a true specialist of analytical chemistry," Dr Martinón-Torres said.
The scientists are using the results to help make sense of alchemical texts.
VALENTINUS' PHILOSOPHER'S STONE
According to the 15th-century alchemist Basilius Valentinus, the first key to making the philosopher's stone was as follows: "Let the diadem of the king be of pure gold, and let the queen that is united to him in wedlock be chaste and immaculate. If you would operate by means of our bodies, take a fierce grey wolf, which is found in the valleys and mountains of the world, where he roams about savage with hunger. Cast to him the body of the king, and when he has devoured it, burn him entirely to ashes in a great fire. By this process the king will be liberated."
Dr Martinón-Torres translates this thus: "To produce pure gold, you need to first remove traces of silver. This can be done by mixing an aggressive mineral called stibnite (Sb2S3) with the impure gold and heating the mixture in a crucible. The pure gold can then be drawn away from the impurities."