Although the origin of solders and soldering is lost to antiquity, it is possible to speculate on how the invention arose. Lead was first obtained as a by-product of silver production. Silver extraction from ores involved cupellation of lead, and the base metal was then recovered from the litharge. (Tylecote 1976). the softness and malleability of lead were clearly recognized, and there exist examples of lead being used as a setting agent to fix posts in the ground and lock morticed stones. It was observed that in this instance the lead filler could give a stronger joint than a simple friction grip.Lead was used by the Mesopotamians (3000 B.C.) to join pieces of copper together, although perhaps more by luck than design since pure lead does not wet copper at all readily. The Romans are known to have produced lead separately from silver, taking advantage of the fact that this metal can be easily extracted from its sulfide ore, galena, simply by roasting the mineral in air (Tylecote 1976)