Nitric acid is an inorganic acid that is composed of approximately 22.2% nitrogen, 76.2% oxygen and 1.6% hydrogen. It is denoted by the chemical formula HNO₃. It was one of the first acids to be prepared and studied. Jabir ibn Hayyan Geber (c. 721-815), an Arabic alchemist, prepared weak nitric during the 700s. Later, alchemists learned that nitric acid, known as aqua fortis (strong water), dissolves most metals but does not affect gold or platinum. They also discovered that with the addition of ammonium chloride, aqua fortis could be transformed into aqua regia (royal water), a combination of nitric acid and hydrochloric acid that dissolves both gold and silver.

When nitric acid and other mineral acids became widely available during the Middle Ages, an experimental revolution occurred. For the first time, alchemists were able to test the purity of precious metals, and to decompose substances without high temperatures and...