Dasyus had Ayas (RV 2.20.8). In RV 4.2.17, "the gods [are] smelting like copper/metal ore the human generations". The references to Ayas in the Rig Veda probably refer to bronze or copper rather than to iron. Scholars like Bhargava maintain that Rigved was written in the Vedic state of Brahmavarta and Khetri Copper mines formed an important location in Brahmavarta. Vedic people had used Copper extensively in agriculture, Water purification, tools, utensils etc., D. K. Chakrabarti (1992) argued: "It should be clear that any controversy regarding the meaning of ayas in the Rgveda or the problem of the Rgvedic familiarity or unfamiliarity with iron is pointless. There is no positive evidence either way. It can mean both copper-bronze and iron and, strictly on the basis of the contexts, there is no reason to choose between the two." Arthashastra The Arthashastra lays down the role of the Director of Metals, the Director of Forest Produce and the Director of Mining. It is the duty of the Director of Metals to establish factories for different metals. The Director of Mines is responsible for the inspection of mines. The Arthashastra also refers to counterfeit coins. Other texts There are many references to Ayas in the early Indian texts. The Atharvaveda and the Shatapatha Brahmana refer to krsna ayas ("black metal"), which could be iron (but possibly also iron ore and iron items not made of smelted iron). There is also some controversy if the term syamayas ("black metal) refers to iron or not. In later texts the term refers to iron. In earlier texts, it could possibly also refer to darker-than-copper bronze, an alloy of copper and tin. Copper can also become black by heating it. Oxidation with the use of sulphides can produce the same effect. The Yajurveda seems to know iron. In the Taittiriya Samhita are references to ayas and at least one reference to smiths. The Satapatha Brahmana 6.1.3.5 refers to the smelting of metallic ore. In the Manu Smriti (6.71), the following analogy is found: "For as the impurities of metallic ores, melted in the blast (of a furnace), are consumed, even so the taints of the organs are destroyed through the suppression of the breath." Metal was also used in agriculture, and the Buddhist text Suttanipata has the following analogy: "for as a ploughshare that has got hot during the day when thrown into the water splashes, hisses