[W/K] :: Sympathetic ink

  Ink \Ink\, n. [OE. enke, inke, OF. enque, F. encre, L. encaustum
     the purple red ink with which the Roman emperors signed their
     edicts, Gr. ?, fr. ? burnt in, encaustic, fr. ? to burn in.
     See Encaustic, Caustic.]
     1. A fluid, or a viscous material or preparation of various
        kinds (commonly black or colored), used in writing or
        printing.
        [1913 Webster]
  
              Make there a prick with ink.          --Chaucer.
        [1913 Webster]
  
              Deformed monsters, foul and black as ink. --Spenser.
        [1913 Webster]
  
     2. A pigment. See India ink, under India.
        [1913 Webster]
  
     Note: Ordinarily, black ink is made from nutgalls and a
           solution of some salt of iron, and consists essentially
           of a tannate or gallate of iron; sometimes indigo
           sulphate, or other coloring matter, is added. Other
           black inks contain potassium chromate, and extract of
           logwood, salts of vanadium, etc. Blue ink is usually a
           solution of Prussian blue. Red ink was formerly made
           from carmine (cochineal), Brazil wood, etc., but
           potassium eosin is now used. Also red, blue, violet,
           and yellow inks are largely made from aniline dyes.
           Indelible ink is usually a weak solution of silver
           nitrate, but carbon in the form of lampblack or India
           ink, salts of molybdenum, vanadium, etc., are also
           used. Sympathetic inks may be made of milk, salts of
           cobalt, etc. See Sympathetic ink (below).
           [1913 Webster]
  
     Copying ink, a peculiar ink used for writings of which
        copies by impression are to be taken.
  
     Ink bag (Zool.), an ink sac.
  
     Ink berry. (Bot.)
        (a) A shrub of the Holly family ({Ilex glabra), found in
            sandy grounds along the coast from New England to
            Florida, and producing a small black berry.
        (b) The West Indian indigo berry. See Indigo.
  
     Ink plant (Bot.), a New Zealand shrub ({Coriaria
        thymifolia), the berries of which yield a juice which
        forms an ink.
  
     Ink powder, a powder from which ink is made by solution.
  
     Ink sac (Zool.), an organ, found in most cephalopods,
        containing an inky fluid which can be ejected from a duct
        opening at the base of the siphon. The fluid serves to
        cloud the water, and enable these animals to escape from
        their enemies. See Illust. of Dibranchiata.
  
     Printer's ink, or Printing ink. See under Printing.
  
     Sympathetic ink, a writing fluid of such a nature that what
        is written remains invisible till the action of a reagent
        on the characters makes it visible.
        [1913 Webster]

  Sympathetic \Sym`pa*thet"ic\, a. [See Sympathy, and cf.
     Pathetic.]
     1. Inclined to sympathy; sympathizing.
        [1913 Webster]
  
              Far wiser he, whose sympathetic mind
              Exults in all the good of all mankind. --Goldsmith.
        [1913 Webster]
  
     2. Produced by, or expressive of, sympathy.
        [1913 Webster]
  
              Ope the sacred source of sympathetic tears. --Gray.
        [1913 Webster]
  
     3. (Physiol.)
        (a) Produced by sympathy; -- applied particularly to
            symptoms or affections. See Sympathy.
        (b) Of or relating to the sympathetic nervous system or
            some of its branches; produced by stimulation on the
            sympathetic nervious system or some part of it; as,
            the sympathetic saliva, a modified form of saliva,
            produced from some of the salivary glands by
            stimulation of a sympathetic nerve fiber.
            [1913 Webster]
  
     Sympathetic ink. (Chem.) See under Ink.
  
     Sympathetic nerve (Anat.), any nerve of the sympathetic
        system; especially, the axial chain of ganglions and
        nerves belonging to the sympathetic system.
  
     Sympathetic powder (Alchemy), a kind of powder long
        supposed to be able to cure a wound if applied to the
        weapon that inflicted it, or even to a portion of the
        bloody clothes. --Dunglison.
  
     Sympathetic sounds (Physics), sounds produced from solid
        bodies by means of vibrations which have been communicated
        to them from some other sounding body, by means of the air
        or an intervening solid.
  
     Sympathetic system (Anat.), a system of nerves and nerve
        ganglions connected with the alimentary canal, the
        vascular system, and the glandular organs of most
        vertebrates, and controlling more or less their actions.
        The axial part of the system and its principal ganglions
        and nerves are situated in the body cavity and form a
        chain of ganglions on each side of the vertebral column
        connected with numerous other ganglions and nerve
        plexuses.
        [1913 Webster]