Scientists have finally unraveled the secrete behind the bronze recipes used by ancient blacksmiths. Through an analysis of a 2300-year-old text and coins, researchers found two elusive ingredients that were used to attain the high-quality bronze of the ancient world.
The researchers analyzed the Kao Gong Ji, one of the oldest technical encyclopedias in the world. The technical text is believed to have been written about 300 B.C., elaborating the chemical formulas for mixing bonze. The text lists several bronze items such as knives, swords, bells and axes and provides formulas on how to make them.
One of the biggest stumbling blocks in understanding these formulas and ingredients has been the inability to translate ancient text properly. For over a century, scientists have been trying to unravel ingredients listed as “jin” and “xi.” For a long time, it was believed that these words meant copper and tin, which played a key part in bronze making. In modern Chinese, the word jin means gold, while in ancient meaning it could have been copper, copper alloy or even just metals. Thus, complicating the ingredients for the formula.
“These recipes were used in the largest bronze industry in Eurasia during this period. Attempts to reconstruct these processes have been made for more than a hundred years, but have failed,” said study coauthor Ruiliang Liu, curator of the Early China Collection at the British Museum.
To fully understand the formula used in making ancient bronze, Liu with the lead study author Mark Pollard analyzed coins minted at the time when the text was written. They found that the chemical composition of the coin was a result of mixing two prepared metal alloys. One of the alloys is made of copper and tin while the other is made of copper and lead.
“For the first time in more than 100 years of scholarship, we have produced a viable explanation of how to interpret the recipes for making bronze objects in early China given in the (Kao Gong Ji),” said Pollard in a statement.
Lead image via Unsplash