VALERIC or VALERIANIC ACID. A volatile fatty acid represented by the formula It is a limpid, colorless, oily fluid of a penetrating odor, similar to that of valerian root, and of an acrid taste. It makes a transpa rent spot on paper, but the spot disappears on ex posure to the air. It is only slightly soluble in water, but dissolves in alcohol and ether in all proportions. It exists in and is obtained by dis tilling valerian root with water acidulated with sulphuric acid. It may be similarly obtained from angelica root, and some other vegetable sources. It is also formed during the oxidation of fats and fatty acid; (especially °tele acid), either by nitric acid or mere exposure to the air, by the oxidation and putrefaction of albuminoids, etc., but the best method of preparing it is by distilling a mixture of amyl alcohol (or fusel oil) with biehromate of potash and sulphuric acid.
The following salts are used in medicine: (1) Valerianate of ammonia, which forms colorless, or white, fiat quadrangular crystals that are de liquescent in the air. (2) l'alcrinnafe of iron, a dark-red amorphous powder which is readily soluble in alcohol, but is insoluble in cold water.
(3) Vaierianate of zinc, which biros brilliant white pearly tabular crystals, with a feeble odor of valerianic acid and a metallic taste. is scarcely soluble in water, in alcohol, or in ether. Valeri anie acid and its salts are supposed to be useful remedies for reflex neuralgia and for various neurotic troubles; but what their action consists in is entirely unknown. Amyl valcrianate,C,11„. is a volatile iluid with a penetrating (slur of apples, slightly soluble in water, but dissolving freely in spirit and in ether. 'In the form of a dilute spirituous solution, it so strongly resembles apples in its smell that it is used in perfumery under the name of oil of app/es, or essence of apples.
The acid described above (boiling point I741°C.) is the modification of valerie acid usually met with. The existence of three other modifications of the same substance is possible according to the structural theory of organic compounds; and, as a matter of fact, all the possible modifications have been prepared by chemical method,. They have, however, no practical value and need not be described here.