In "autogenous soldering" two pieces of metal are united by the melting of the opposing surfaces, without the use of a separate fusible alloy or solder as a cementing material.
Soldering, brazing and the blowpipe in the Cordilleran provinces are suspected, but the evidence of their existence must be further examined.
The blowpipe has been in common use from the earliest times for soldering metals and working glass, but its introduction into systematic chemical analysis is to be ascribed to A.
In gold work the earliest jewelry, that of King Zer of the 1st Dynasty, shows a perfect mastery of working hollow balls with minute threading holes, and of soldering with no trace of excess nor difference of color.
Its use in soldering depends on the fact that solder only adheres to the surface of an untarnished metal, and consequently a little borax is placed on the surface of the metal and heated by the soldering iron in order to remove any superficial film of oxide.