Valerianic Acid, Or Valeric Acid, an acid which bears the same relation to amylic alcohol that acetic acid does to ethylic or common alcohol. It was first obtained by Chevreul in 1817 from the fat of a dolphin, delphinum phocoena, and was called delphinic or phocenic acid. In 1830 Grote obtained from the essential oil of valerian an acid which he called valerianic acid, and which was shown by Trommsdorff and Ettling to be identical with Ohevreul's delphinic acid. It was afterward produced by oxidation of amylic alcohol by Dumas and Stas, who pointed out its relation to this body and showed its composition to be O5H10O2. It is found in many vegetables, as valerian, angelica, and several other roots, in the fruit and bark of viburnum opulus, in the bark of the elder, and in many composite plants. It is also produced by the oxidation of fats and the putrefaction of albuminous substances. It is prepared from amylic alcohol by adding to it twice its weight of strong sulphuric acid, and passing this slowly into a solution of bichromate of potash, and, after heating for some time in a flask, distilling and saturating the distillate with sodium carbonate. Sodium valerianate is produced, which is treated with sulphuric acid and distilled.
It is a colorless, mobile oil, having a sour, burning taste, and an odor resembling oil of valerian combined with rancid cheese. Its specific gravity at 61° is 0.937, according to Dumas and Stas; and its index of refraction, according to Delffs, is 1.3952. It affects the plane of polarization of light according as it has been prepared from active or inactive amylic alcohol. The active modification produces a rotation of +43° in a tube 50 centimetres long. It boils at 347° F., and remains liquid and transparent at 5°. It dissolves in 30 parts of water at 53.6°, and in all proportions with alcohol and ether. Its vapor passed through a red-hot tube is converted into carbonic anhydride, carbonic oxide, ethylene, tritylene, and tetrylene, with sometimes light carburetted hydrogen. It is monobasic, forming neutral salts having the general formula C6H9M02, and a few acid and basic salts. - The valerianates are unctuous to the touch, inodorous when dry, but with a pungent strong smell of valerianic acid when moist, which is heightened by warmth. Valerianate of ammonia is prepared by passing ammoniacal gas through valerianic acid. It crystallizes in white, pearly, four-sided, tabular crystals, having an offensive odor.
It is often formed in the putrefaction of organic bodies, and is a frequent constituent of rancid cheese. It was introduced as a therapeutic agent by M. Déclat of Paris for the treatment of neuralgia; it may be given in doses of one or two grains of the salt dissolved in water. Valerianate of bismuth has been used successfully in neuralgia and painful affections of the stomach, in doses of from one to two grains. Valerianate of iron is often used in hysterical affections complicated with chlorosis, in doses of one grain, repeated several times a day. Valerianate of quinia is prepared by dissolving the alkaloid in valerianic acid and evaporating the solution below 120° F. It is a colorless salt, crystallizing in rhombohedral plates having a bitter taste and a powerful, repulsive odor, soluble in 110 parts of cold and 40 parts of boiling water. By continuing the boiling, the salt is decomposed with evolution of valerianic acid. It is given in cases of debility and nervous affections, in doses of one or two grains several times a day. Valerianate of atropia, the active principle of atropa belladonna, has been employed with benefit in epilepsy and other nervous diseases, in very minute doses. Valerianate of zinc is prepared by the action of valerianate of soda on sulphate of zinc.
It possesses decided antispasmodic properties, and has been used with advantage by Dr. Namias of Venice, Italy, in nervous affections attended with palpitation of the heart, and by Dr. Francois Devay of Lyons, France, in epilepsy and in nervous affections accompanying chlorosis. The valerianic ethers, or valerianates of the alcohol radicals, are prepared by distilling valerianate of sodium with sulphuric acid and the corresponding alcohols. Amylic valerianate dissolved in six or eight parts of alcohol forms a flavoring liquid known as apple essence.