he , an administrative text dating to late in China’s Eastern Zhou Dynasty (771–256 B.C.), includes six recipes for creating bronze objects such as bells, mirrors, and . Some scholars have assumed that Jin was copper and Xi was tin, but if this were the case, the recipes would have produced metal with far higher tin concentrations than has been detected in Eastern Zhou bronze items. Moreover, these bronze artifacts generally contain at least 10 percent lead. While lead can be a contaminant in copper, this would not account for the levels of lead that have been measured.
