Where the first man discovered type metallic and natural copper ' (Native copper) Gold (Gold) "and" a "because it can hit the plate without using heat. Before coming to วิวัฒน to smelt metals. (Smelting) and use the heat to melt metal casting. (Casting)
The first metal that man discovered and adopted a "natural copper (Native copper)" and "Gold (Gold)" I can hit a pad without using heat. Prior to the evolution of smelting metals (Smelting) and using heat to melt the metal casting (Casting).
The first type metal humans discovered and used is the "copper nature (Native copper.)" and "gold (Gold.)" because they can hit the sheets without the use of heat. Prior to march toward smelting metal (Smelting).(Casting) .