a. [ad. F. xanthique, f. Gr. ξανθός yellow: see -IC.]
1. Chem. Epithet of certain compounds which produce substances of a yellow color, or of bodies connected with these. a. Xanthic oxide, the original name of XANTHINE; so xanthic calculus, a urinary calculus containing xanthine.
1817. Marcet, Ess. Chem. Hist. Calculous Disorders iv. 99. If the potash be added to the pure xanthic substance,… no change of colour takes place. The residue of the solution of xanthic oxyd in water produces the yellow substance, when treated with nitric acid. Ibid., 101. Xanthic oxyd. Ibid., 102. In burning, it emitted an animal smell, which did not at all resemble that of the lithic, cystic, or xanthic calculus.
1857. Miller, Elem. Chem., Org., 642. Xanthic or Uric Oxide (C10H4N4O4) was discovered by Dr. Marcet as the principal constituent of a very rare variety of urinary calculus.
1872. T. Bryant, Pract. Surg. (1879), II. 84. Calculi of uric acid and the urates, with their modifications the oxalates, xanthic and cystic oxide.
b. Xanthic acid, a complex acid containing sulphur and carbon, also called sulphocarbethylic or ethyldisulphocarbonic acid (C3H6OS2), many of whose salts (xanthates) are yellow. So xanthic ether, etc.
1831. T. Thomson, Syst. Chem. (ed. 7), II. 176. Xanthic acid is characterized by precipitating the salts of copper yellow. Ibid., During the distillation of xanthate of potash, a substance comes over which Zeise has distinguished by the name of xanthic oil.
1857. Miller, Elem. Chem., Org., 146. Xanthic or Sulphocarbethylic Acid.
1868. Watts, Dict. Chem., V. 498. Ethyldisulphocarbonic or Xanthic Acid … is a colourless oil, heavier than water,… its taste is acid, astringent, and bitter. Ibid., 500. Ethylic Disulphocarbonate or Xanthate, Xanthic Ether, C5H10OS2 … has a pale-yellow colour, a sweetish taste.
2. Bot. De Candolle’s name for a series or class of colors in flowers, of which the type is yellow: opp. to cyanic.
1843. Florist’s Jrnl. (1846), IV. 34. A most uncommon combination of colours—cyanic and xanthic tints in one and the same flower.
1885. Goodale, Physiol. Bot. (1892), 454.
