Mysterious Ingredients of Ancient Bronze Items Deciphered

An analysis of the 2,300-year-old text, as well as the composition of the coins, helped researchers decipher the ancient recipes for making bronze.

Cao 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 they were made.

For the past 100 years, researchers have struggled to translate the two main ingredients, which are listed as jin and si. Experts believed that these words meant copper and tin, which are key components in the process of making bronze. However, when the researchers tried to recreate the recipes, the resulting metal did not match the composition of ancient Chinese artifacts.

Now, two researchers believe they have pinpointed the true meaning of the mysterious ingredients. Antiquity magazine published its findings on Tuesday.

The discovery allows for a better understanding of ancient bronze production and opens up new questions about when the process began, given that large-scale bronze production occurred long before the six recipes were published in Cao Gong Ji, said study co-author Ruiliang L, curator of the Early China Collection. in the British Museum in London.

In modern Chinese, jin means gold. But the ancient meaning of the word could mean copper, a copper alloy, or even just metal, so it was hard to pinpoint the specific ingredients.

“These recipes were used in the largest bronze industry in Eurasia at that time,” said Liu. analysis

Liu and the lead author of the study, Mark Pollard, analyzed the chemical composition of Chinese coins minted shortly before Kao Gong Ji was written. Pollard is Edward Hall Professor of Archeology at the University of Oxford and director of the Archeology and Art History Research Laboratory.

Previously, researchers thought the coins were made by diluting copper with tin and lead.

The analysis showed that the chemical composition of the coins was formed by mixing two pre-prepared metal alloys, one of which consisted of copper, tin and lead, and the other of copper and lead.

The two researchers concluded that jin and xi were probably premixed metal alloys.

“For the first time in over 100 years of research, we have provided a viable explanation for how to interpret the recipes for making bronze objects in early China,” Pollard concluded.