Gold parting will not dissolve gold, nearly pure gold (very close to 99.5% pure) will be left behind after the reaction is complete. After removing the solid gold other elements like silver and copper may be extracted from the liquid. To get the gold to a very high level of purity (999 fine gold) it is sometimes processed further with aqua regia to effectively remove all the impurities. Aqua regia was also used for parting. It was made by adding sal ammoniac to nitric acid which produced a mixture of hydrochloric acid and nitric acid. This acid dissolved the gold to a
Metal Gear Acid forces team to investigate, but the team is obliterated by armed resistance. With no other options and time running out, the US government calls Solid Snake to infiltrate the laboratory, discover the nature of Pythagoras, and to rescue Senator Hach. According to an interview originally published by "Electronic Gaming Monthly" with the game's producer, Masahiro Hinami, the 'Acid' part of the title actually has three different meanings. The first meaning refers to "Acid's" departure from the previous "Metal Gear" games in terms of style, which is an analogue to acid's ability to dissolve metal. The second is a reference to