A liquid containing about 68 per cent., by weight, of hydrogen nitrate, HNO3.

Properties : Nitric acid is colorless, fuming, very caustic and corrosive and has a peculiar, somewhat suffocating odor. It is miscible with water in all proportions, dissolves mercury and most other metals with evolution of red fumes and stains woolen fabrics and animal tissues a bright yellow.

Incompatibilities: Like other inorganic acids, it is incompatible with alkalies, the alkali carbonates, many of the salts of organic acids, and, because of its oxidizing properties, with all readily oxidizable substances. Its addition to organic liquids (alcohol, etc.), is apt to give rise to explosive reactions.

Action and Uses : Nitric acid is a powerful caustic, used for removing warts and small nevi and for cauterizing chancroids and other sores and bites of rabid animals, but its action is very painful and not readily controlled. When nitric acid is used as a caustic, the surrounding healthy tissue should be coated with petrolatum and the acid applied on the end of a rod of glass or wood.