1836–41 W. T. Brande (ed. 5) 1198 Verdic Acid.—This acid was extracted by Runge from several of the Umbelliferæ and Plantagineæ, &c., but chiefly from the root of the Scabiosa succisa.
1843 XXVI. 256/1 Runge states that he found by analysis that verdic acid contains one equivalent of oxygen more than the verdous acid.