The probability of the correctness of this formula is supported by the possibility of the following derivatives: monomethylellagic acid, C'14H'6O'7(O.CH'3); dimethylellagic acid, C'14H'4O'6(O.CH'3)'2; tetramethylellagic acid, C'14H'2O'4(O.CH'3)'4; phenylhydrazinellagic acid, C'14H'6O'8.N'2H'3C'6H'5. By the electrolytic reduction of ellagic acid, hexoxydiphenyl, (OH)'3C'6H'2-C'6H'2(OH)'3, is obtained; the ordinary methods of reduction yield leucoellagic acid, C'14H'10O'8, which crystallises in small sharp needles, melting with decomposition at 294°-295° C. Leucoellagic acid is soluble in ethyl and methyl alcohols, and in glacial acetic acid, insoluble in chloroform, benzene, toluene, carbon tetrachloride, and petrol ether; it gives a bluish-green colour with ferric chloride which quickly turns black. Leucoellagic acid is soluble in alkalies, the solution assuming a deep-red coloration; it reduces silver nitrate in the cold, but is not adsorbed by mordanted cotton cloth, in which respect it differs from ellagic acid.[Footnote: Liebig's _Ann_., 1912, 394, 249. ELLAGITANNIC ACID, C'26H'28'O'10-3H'2O, is closely related to ellagic acid; the former consists of faintly yellow needles, M.P. 329°-336°C. It is soluble in water, precipitates gelatine, and is adsorbed by hide powder. It occurs with gallic acid, tannin, and ellagic acid in dividivi, myrabolams, algarobilla, and chestnut wood extracts. Other bodies of this class include:-- METELLAGIC ACID, Cl_4H_6O_5, derived from methoxybenzoic acid, and recrystallised from acetic acid, forms small crystalline needles, M.P. 273°-276° C., and yields fluorene on distillation with zinc dust. ----CO.O---- ^ ---------- ^ | | | | V ---O.CO--- V OH FLAVELLAGIC ACID, C_14H_6O_9, is obtained by the oxidation of gallic acid with concentrated sulphuric acid and potassium persulphate. It crystallises from pyridine in prismatic needles melting above 360° C. Distillation with zinc dust yields fluorene (see above)-- ----CO.O---- ^ ---------- ^ OH | | | | HO V ---O.CO--- V OH OH OH By heating ellagic acid for three-quarters of an hour at 185° C. with concentrated sulphuric acid, ceruleo-ellagic acid (dioxyellagic acid), C_14H_6O_10, is formed as yellowish needles, M.P. 360° C., which are but little soluble in the usual solvents. The acid is slightly soluble in strong caustic soda solution, the colour of the solution, on diluting, changing to green and blue. LUTEIC ACID (Luteo Saure, pentoxybiphenylmethylolide carboxylic acid),C_14H_8O_9, occurs, in addition to ellagic acid, in myrabolams-- [Footnote: _Ber_., 1909, 42, 353.] ----CO.O---- ^ ---------- ^ OH | | | | HO V OH HOOC V OH OH OH