Pure blue

Pure \Pure\, a. [Compar. {Purer}; superl. {Purest}.] [OE. pur,
   F. pur, fr. L. purus; akin to putus pure, clear, putare to
   clean, trim, prune, set in order, settle, reckon, consider,
   think, Skr. p? to clean, and perh. E. fire. Cf. {Putative}.]
   1. Separate from all heterogeneous or extraneous matter; free
      from mixture or combination; clean; mere; simple; unmixed;
      as, pure water; pure clay; pure air; pure compassion.
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            The pure fetters on his shins great.  --Chaucer.
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            A guinea is pure gold if it has in it no alloy. --I.
                                                  Watts.
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   2. Free from moral defilement or quilt; hence, innocent;
      guileless; chaste; -- applied to persons. "Keep thyself
      pure." --1 Tim. v. 22.
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            Now the end of the commandment is charity out of a
            pure heart, and of a good conscience. --1 Tim. i. 5.
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   3. Free from that which harms, vitiates, weakens, or
      pollutes; genuine; real; perfect; -- applied to things and
      actions. "Pure religion and impartial laws." --Tickell.
      "The pure, fine talk of Rome." --Ascham.
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            Such was the origin of a friendship as warm and pure
            as any that ancient or modern history records.
                                                  --Macaulay.
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   4. (Script.) Ritually clean; fitted for holy services.
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            Thou shalt set them in two rows, six on a row, upon
            the pure table before the Lord.       --Lev. xxiv.
                                                  6.
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   5. (Phonetics) Of a single, simple sound or tone; -- said of
      some vowels and the unaspirated consonants.
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   {Pure-impure}, completely or totally impure. "The inhabitants
      were pure-impure pagans." --Fuller.

   {Pure blue}. (Chem.) See {Methylene blue}, under {Methylene}.
      

   {Pure chemistry}. See under {Chemistry}.

   {Pure mathematics}, that portion of mathematics which treats
      of the principles of the science, or contradistinction to
      applied mathematics, which treats of the application of
      the principles to the investigation of other branches of
      knowledge, or to the practical wants of life. See
      {Mathematics}. --Davies & Peck (Math. Dict. )

   {Pure villenage} (Feudal Law), a tenure of lands by uncertain
      services at the will of the lord. --Blackstone.
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   Syn: Unmixed; clear; simple; real; true; genuine;
        unadulterated; uncorrupted; unsullied; untarnished;
        unstained; stainless; clean; fair; unspotted; spotless;
        incorrupt; chaste; unpolluted; undefiled; immaculate;
        innocent; guiltless; guileless; holy.
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Methylene \Meth"yl*ene\, n. [F. m['e]thyl[`e]ne, from Gr. ? wine
   + ? wood; -- a word coined to correspond to the name wood
   spirit.] (Chem.)
   A divalent hydrocarbon radical, {-CH2-}, not known in the
   free state, but regarded as an essential residue and
   component of certain derivatives of methane; as, methylene
   bromide, {CH2Br2}; -- formerly called also {methene}.
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   {Methylene blue} (Chem.), an artificial dyestuff consisting
      of a complex sulphur derivative of diphenyl amine; --
      called also {pure blue}.
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