and smokes in volumes..." In the Charaka Samhita an analogy occurs that probably refers to the lost wax technique. The Silpasastras (the Manasara, the Manasollasa (Abhilashitartha Chintamani) and the Uttarabhaga of Silparatna) describe the lost wax technique in detail. The Silappadikaram says that copper-smiths were in Puhar and in Madura. According to the History of the Han Dynasty by Ban Gu, Kashmir and "Tien-chu" were rich in metals. An influential Indian metallurgist and alchemist was Nagarjuna (born 931). He wrote the treatise Rasaratnakara that deals with preparations of rasa (mercury) compounds. It gives a survey of the status of metallurgy and alchemy in the land. Extraction of metals such as silver, gold, tin and copper from their ores and their purification were also mentioned in the treatise. The Rasa Ratnasamuccaya describes the extraction and use of copper. Archaeology Chakrabarti (1976) has identified six early iron-using centres in India: Baluchistan, the Northwest, the Indo-Gangetic divide and the upper Gangetic valley, eastern India, Malwa and Berar in central India and the megalithic south India. The central Indian region seems to be the earliest iron-using centre. According to Tewari, iron using and iron "was prevalent in the Central Ganga Plain and the Eastern Vindhyas from the early 2nd millennium BC." The earliest evidence for smelted iron in India dates to 1300 to 1000 BCE. These early findings also occur in places like the Deccan and the earliest evidence for smelted iron occurs in Central India, not in north-western India. Moreover, the dates for iron in India are not later than in those of Central Asia, and according to some scholars (e.g. Koshelenko 1986) the dates for smelted iron may actually be earlier in India than in Central Asia and Iran. The Iron Age did however not necessary imply a major social transformation, and Gregory Possehl wrote that "the Iron Age is more of a continuation of the past then a break with it". Archaeological data suggests that India was "an independent and early centre of iron technology." According to Shaffer, the "nature and context of the iron objects involved [of the BRW culture] are very different from early iron objects found in Southwest Asia." In Central Asia, the development of iron technology was not necessarily connected with Indo-Iranian migrations either. J.M. Kenoyer (1995) also remarks that there is a "long break in tin acquisition" necessary for the production of "tin bronzes" in the