By distilling nitric acid from camphor, it is more completely changed, and by this process is converted into an acid, which has received the name of campho ric acid. The process consists in distill ing from four ounces of camphor in a re tort, Wt. of nitric acid, so far diluted as to be of the specific gravity of 1.33, the heat being gradually applied by the me dium of a sand-bath : nitric oxide and carbonic acid gases are disengaged ; part of the camphor rises in %apour, while the other part receives oxygen from the acid.
Camphoric acid, thus produced, is dif ferent from all the known acids. It has a slightly acid bitter taste, and reddens in. fusion of litmus. Its crystals effloresce on exposure to the air ; tliey are sparing ly soluble in cold water, I'm ounce of wa ter at 50° of Fahrenheit not dissolving more than 6 grains; at 212°, about 48 grains are dissolved. When the acid is placed on ignited fuel, it emits a dense aromatic vapour, and is entirely dissipat ed. By applying heat to it in close ves sels, it first melts and sublimes, but by a higher heat its properties are changed ; it no longer reddens litmus, acquires an aromatic smell, its taste is less penetrat ing, and it is no longer soluble in water, or in sulphuric or inuriatic acid. Nitric
acid heated on it turns it yellow, and dis solves it.
Camphoric acid is soluble in the mine ral acids : it is likewise soluble in alcohol. and in the volatile and fixed oils. It pro duces no change in sulphur. The salts, formed by this acid, with the alkaline, earthy, and metallic bases, are named Camphorates. Their properties have been examined by La Grange. Their taste is somewhat bitter: they are de composed by heat, the acid being sublim ed: and they all exhibit a blue flame when the blow-pipe. The alkaline and earthy camphorates are form ed by adding the camphoric acid to the alkali or earth, either pure, or in the state of carbonate ; the carbonic acid, in the latter case, being disengaged.