资料来源 : pyDict

天然气

资料来源 : Webster's Revised Unabridged Dictionary (1913)

   10. (Mus.)
       (a) Produced by natural organs, as those of the human
           throat, in distinction from instrumental music.
       (b) Of or pertaining to a key which has neither a flat
           nor a sharp for its signature, as the key of C major.
       (c) Applied to an air or modulation of harmony which
           moves by easy and smooth transitions, digressing but
           little from the original key. --Moore (Encyc. of
           Music).

   {Natural day}, the space of twenty-four hours. --Chaucer.

   {Natural fats}, {Natural gas}, etc. See under {Fat}, {Gas}.
      etc.

   {Natural Harmony} (Mus.), the harmony of the triad or common
      chord.

   {Natural history}, in its broadest sense, a history or
      description of nature as a whole, incuding the sciences of
      {botany}, {zo["o]logy}, {geology}, {mineralogy},
      {paleontology}, {chemistry}, and {physics}. In recent
      usage the term is often restricted to the sciences of
      botany and zo["o]logy collectively, and sometimes to the
      science of zoology alone.

   {Natural law}, that instinctive sense of justice and of right
      and wrong, which is native in mankind, as distinguished
      from specifically revealed divine law, and formulated
      human law.

   {Natural modulation} (Mus.), transition from one key to its
      relative keys.

   {Natural order}. (Nat. Hist.) See under {order}.

   {Natural person}. (Law) See under {person}, n.

   {Natural philosophy}, originally, the study of nature in
      general; in modern usage, that branch of physical science,
      commonly called {physics}, which treats of the phenomena
      and laws of matter and considers those effects only which
      are unaccompanied by any change of a chemical nature; --
      contrasted with mental and moral philosophy.

   {Natural scale} (Mus.), a scale which is written without
      flats or sharps. Model would be a preferable term, as less
      likely to mislead, the so-called artificial scales (scales
      represented by the use of flats and sharps) being equally
      natural with the so-called natural scale

   {Natural science}, natural history, in its broadest sense; --
      used especially in contradistinction to mental or moral
      science.

   {Natural selection} (Biol.), a supposed operation of natural
      laws analogous, in its operation and results, to designed
      selection in breeding plants and animals, and resulting in
      the survival of the fittest. The theory of natural
      selection supposes that this has been brought about mainly
      by gradual changes of environment which have led to
      corresponding changes of structure, and that those forms
      which have become so modified as to be best adapted to the
      changed environment have tended to survive and leave
      similarly adapted descendants, while those less perfectly
      adapted have tended to die out though lack of fitness for
      the environment, thus resulting in the survival of the
      fittest. See {Darwinism}.

   {Natural system} (Bot. & Zo["o]l.), a classification based
      upon real affinities, as shown in the structure of all
      parts of the organisms, and by their embryology.

            It should be borne in mind that the natural system
            of botany is natural only in the constitution of its
            genera, tribes, orders, etc., and in its grand
            divisions.                            --Gray.
      

   {Natural theology}, or {Natural religion}, that part of
      theological science which treats of those evidences of the
      existence and attributes of the Supreme Being which are
      exhibited in nature; -- distinguished from revealed
      religion. See Quotation under {Natural}, a., 3.

   {Natural vowel}, the vowel sound heard in urn, furl, sir,
      her, etc.; -- so called as being uttered in the easiest
      open position of the mouth organs. See {Neutral vowel},
      under {Neutral} and Guide to Pronunciation, [sect] 17.

   Syn: See {Native}.



   {Gas fitter}, one who lays pipes and puts up fixtures for
      gas.

   {Gas fitting}.
      (a) The occupation of a gas fitter.
      (b) pl. The appliances needed for the introduction of gas
          into a building, as meters, pipes, burners, etc.

   {Gas fixture}, a device for conveying illuminating or
      combustible gas from the pipe to the gas-burner,
      consisting of an appendage of cast, wrought, or drawn
      metal, with tubes upon which the burners, keys, etc., are
      adjusted.

   {Gas generator}, an apparatus in which gas is evolved; as:
      (a) a retort in which volatile hydrocarbons are evolved by
          heat;
      (b) a machine in which air is saturated with the vapor of
          liquid hydrocarbon; a carburetor;
      (c) a machine for the production of carbonic acid gas, for
          a["e]rating water, bread, etc. --Knight.

   {Gas jet}, a flame of illuminating gas.

   {Gas machine}, an apparatus for carbureting air for use as
      illuminating gas.

   {Gas meter}, an instrument for recording the quantity of gas
      consumed in a given time, at a particular place.

   {Gas retort}, a retort which contains the coal and other
      materials, and in which the gas is generated, in the
      manufacture of gas.

   {Gas stove}, a stove for cooking or other purposes, heated by
      gas.

   {Gas tar}, coal tar.

   {Gas trap}, a drain trap; a sewer trap. See 4th {Trap}, 5.

   {Gas washer} (Gas Works), an apparatus within which gas from
      the condenser is brought in contact with a falling stream
      of water, to precipitate the tar remaining in it.
      --Knight.

   {Gas water}, water through which gas has been passed for
      purification; -- called also {gas liquor} and {ammoniacal
      water}, and used for the manufacture of sal ammoniac,
      carbonate of ammonia, and Prussian blue. --Tomlinson.

   {Gas well}, a deep boring, from which natural gas is
      discharged. --Raymond.

   {Gas works}, a manufactory of gas, with all the machinery and
      appurtenances; a place where gas is generated for lighting
      cities.

   {Laughing gas}. See under {Laughing}.

   {Marsh gas} (Chem.), a light, combustible, gaseous
      hydrocarbon, {CH4}, produced artificially by the dry
      distillation of many organic substances, and occurring as
      a natural product of decomposition in stagnant pools,
      whence its name. It is an abundant ingredient of ordinary
      illuminating gas, and is the first member of the paraffin
      series. Called also {methane}, and in coal mines, {fire
      damp}.

   {Natural gas}, gas obtained from wells, etc., in
      Pennsylvania, Ohio, and elsewhere, and largely used for
      fuel and illuminating purposes. It is chiefly derived from
      the Coal Measures.

   {Olefiant gas} (Chem.). See {Ethylene}.

   {Water gas} (Chem.), a kind of gas made by forcing steam over
      glowing coals, whereby there results a mixture of hydrogen
      and carbon monoxide. This gives a gas of intense heating
      power, but destitute of light-giving properties, and which
      is charged by passing through some volatile hydrocarbon,
      as gasoline.

资料来源 : WordNet®

natural gas
     n : a fossil fuel in the gaseous state; used for cooking and
         heating homes [syn: {gas}]