Gold parting in 1860's Australia. It is able to refine gold up to 99.5% purity. The process involves blowing a stream of chlorine gas over and through a crucible filled with molten impure gold. Impurities in the gold form chlorides before the gold does and these insoluble salts are removed from the melt by skimming the surface. Invented by Emil Wohlwill in 1874, this produces the highest purity gold (99.999%). It is an electrolytic process using pure gold for the cathode (or titanium as a starter cathode) and chloroauric acid (gold chloride-hydrochloric acid) as the electrolyte; this is made by dissolving gold
Simple commodity production Simple commodity production Simple commodity production (also known as "petty commodity production"; the German original phrase is "") is a term coined by Frederick Engels to describe productive activities under the conditions of what Marx had called the "simple exchange" of commodities, where independent producers trade their own products. The use of the word "simple" does not refer to the nature of the producers or of their production, but to the relatively simple and straightforward exchange processes involved. Simple exchange of commodities is as old as the history of trade, insofar as it has progressed beyond barter, and occurred for