Acid test (gold) mark is tested by applying aqua fortis (nitric acid), which dissolves the mark of any item that is not gold. If the mark remains, it is tested by applying aqua regia (nitric acid and hydrochloric acid). If the mark is removed, then this test dissolves the gold, proving the item to be genuine gold. More accurate testing of the item for its fineness or purity can be done through the use of differing strengths of aqua regia and comparative testing of gold items of known fineness. The figurative meaning of the expression, where it is applied to tests of character,
Metal Gear Acid 2 "MGS3", a Banana Skin, Possessed Arm, and Emma's Parrot. The game's soundtrack was composed by Akihiro Honda, Hiroshi Tanabe, Nobuko Toda and Shuichi Kobori. It was released along with the "Metal Gear Acid" soundtrack on December 21, 2005, in the two-disc compilation "Metal Gear Acid 1 and 2 Original Soundtrack". "Metal Gear Acid 2" received generally positive reviews from critics and the public. Metal Gear Acid 2 , stylized as METAL GEAR AC!D², is a turn-based collectible card stealth game developed by Kojima Productions and published by Konami for the PlayStation Portable in 2005. A Java ME version for mobile