An analysis of 2,300-year-old text and coins has helped researchers decipher ancient bronze recipes, including two linguistically elusive ingredients.
Kao Gong Ji, the oldest known technical encyclopedia, was written around 300 BC and is part of a larger text called The Rites of Zhou.
The ancient text includes six chemical formulas for mixing bronze and lists items such as swords, bells, axes, knives and mirrors, as well as how to make them.
For the past 100 years, scientists have struggled to translate two of the main ingredients, listed as “jin” and “xi”. Experts believed these words translated to copper and tin, which are key components in the bronze-making process.
When the researchers tried to recreate the recipes, however, the resulting metal did not match the composition of ancient Chinese artifacts.
Now, two researchers believe they have accurately identified the true meaning behind the mysterious ingredients. The journal Antiquity published the findings on Tuesday (9).
The revelation allows for a better understanding of ancient bronze production — and opens up new questions about when this process began, as large-scale bronze production happened long before the six recipes were shared at Kao Gong Ji, said the co-author of the study Ruiliang Liu, curator of the Early China Collection at the British Museum in London.
In modern Chinese, jin means gold. But the ancient meaning of the word could be copper, copper alloy, or even just metal, which is why it has been difficult to determine the specific ingredients.
“These recipes were used in Eurasia’s largest bronze industry during this period,” Liu said in a statement. “Attempts to reconstruct these processes have been made for over a hundred years, but have failed.”
Chemical analysis
Liu and the study’s lead author, Mark Pollard, analyzed the chemical composition of Chinese knives minted close to when Kao Gong Ji was written. Pollard is Professor of Archeological Sciences at the University of Oxford and Director of the Research Laboratory in Archeology and Art History.
Previously, researchers thought knives were made by diluting copper with tin and lead.
The analysis showed that the chemical composition of the coins was the result of mixing two pre-prepared metal alloys, one of copper, tin and lead, and the other of copper and lead.
The two researchers concluded that jin and xi were likely premixed metal alloys.
“For the first time in more than 100 years of studies, we have produced a viable explanation of how to interpret the recipes for making bronze objects in early China given in (Kao Gong Ji),” Pollard said in a statement.
The findings showed that ancient Chinese manufacture of bronze relied on combining alloys rather than pure metals and that metallurgy was more complex than previously thought.
“This indicates an additional step — the production of pre-prepared alloys — in the process of making copper alloy objects in early China,” Liu said.
“This represents an additional, but previously unknown, layer in the metal production and supply network in China.”
Archaeologically, this additional step would have remained invisible were it not for chemical analysis, the researchers said.
“Understanding alloy practice is crucial to understanding exquisite bronze ritual vessels, as well as the underlying mass production in Shang and Zhou societies,” said Liu.
Using this type of analysis could help researchers decipher other texts on ancient metallurgy from different cultures and regions in the future, the researchers said.
Source: CNN Brasil
