Succinic Acid, an acid found ready formed in amber and in certain lignites, and occasionally in the animal organism. It may be obtained in colored crystals by heating amber in retorts. It is formed artificially in several ways, as by the action of hydriodic acid on malic acid or tartaric acid, or by the oxidation of certain fatty acids. It is most conveniently prepared by the fermentation of malic acid, the crude malate of calcium obtained by adding chalk or slaked lime to the juice of mountain ash berries being used for the purpose. The malate is mingled with water and yeast or decaying cheese, and kept for a few days at 86° or 100° F., when succinate of calcium forms. This salt is then decomposed by sulphuric acid, insoluble sulphate of lime being thrown down, while succinic acid is left in solution, and may be obtained by evaporation and cooling in colorless oblique rhombic prisms, soluble in five parts of cold and three parts of boiling water. The combinations of succinic acid with bases are called succinates, of which the most important are the calcium succinate above mentioned and succinate of ammonia. Succinic acid, though formerly officinal, is now seldom used in medicine.
Succinate of ammonia is said to have been used with success in delirium tremens.