The only original contribution of this paper lies in theorizing the mechanism by which Keum-boo works. A metallurgist observing a keum-boo demonstration informed me that above a certain temperature thin gold foil begins to pass oxygen atoms through itself and is actually used as a filter material for gases in some industrial applications. Theoretically then the gold when thin enough passes oxygen through and with pressure (burnishing) produces oxygen-free conditions in contact with the silver (or other metal) below it -- allowing pressure welding to occur.