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

Methane \Meth"ane\, n. [See {Methal}.] (Chem.)
   A light, colorless, gaseous, inflammable hydrocarbon, {CH4};
   marsh gas. See {Marsh gas}, under {Gas}.

   {Methane series} (Chem.), a series of saturated hydrocarbons,
      of which methane is the first member and type, and
      (because of their general chemical inertness and
      indifference) called also the {paraffin (little affinity)
      series}. The lightest members are gases, as methane,
      ethane; intermediate members are liquids, as hexane,
      heptane, etc. (found in benzine, kerosene, etc.); while
      the highest members are white, waxy, or fatty solids, as
      paraffin proper.

Type \Type\, n. [F. type; cf. It. tipo, from L. typus a figure,
   image, a form, type, character, Gr. ? the mark of a blow,
   impression, form of character, model, from the root of ? to
   beat, strike; cf. Skr. tup to hurt.]
   1. The mark or impression of something; stamp; impressed
      sign; emblem.

            The faith they have in tennis, and tall stockings,
            Short blistered breeches, and those types of travel.
                                                  --Shak.

   2. Form or character impressed; style; semblance.

            Thy father bears the type of king of Naples. --Shak.

   3. A figure or representation of something to come; a token;
      a sign; a symbol; -- correlative to antitype.

            A type is no longer a type when the thing typified
            comes to be actually exhibited.       --South.

   4. That which possesses or exemplifies characteristic
      qualities; the representative. Specifically:
      (a) (Biol.) A general form or structure common to a number
          of individuals; hence, the ideal representation of a
          species, genus, or other group, combining the
          essential characteristics; an animal or plant
          possessing or exemplifying the essential
          characteristics of a species, genus, or other group.
          Also, a group or division of animals having a certain
          typical or characteristic structure of body maintained
          within the group.

                Since the time of Cuvier and Baer . . . the
                whole animal kingdom has been universally held
                to be divisible into a small number of main
                divisions or types.               --Haeckel.
      (b) (Fine Arts) The original object, or class of objects,
          scene, face, or conception, which becomes the subject
          of a copy; esp., the design on the face of a medal or
          a coin.
      (c) (Chem.) A simple compound, used as a mode or pattern
          to which other compounds are conveniently regarded as
          being related, and from which they may be actually or
          theoretically derived.

   Note: The fundamental types used to express the simplest and
         most essential chemical relations are hydrochloric
         acid, {HCl}; water, {H2O}; ammonia, {NH3}; and methane,
         {CH4}.

   5. (Typog.)
      (a) A raised letter, figure, accent, or other character,
          cast in metal or cut in wood, used in printing.
      (b) Such letters or characters, in general, or the whole
          quantity of them used in printing, spoken of
          collectively; any number or mass of such letters or
          characters, however disposed.

   Note: Type are mostly made by casting type metal in a mold,
         though some of the larger sizes are made from maple,
         mahogany, or boxwood. In the cut, a is the body; b, the
         face, or part from which the impression is taken; c,
         the shoulder, or top of the body; d, the nick
         (sometimes two or more are made), designed to assist
         the compositor in distinguishing the bottom of the face
         from the top; e, the groove made in the process of
         finishing, -- each type as cast having attached to the
         bottom of the body a jet, or small piece of metal
         (formed by the surplus metal poured into the mold),
         which, when broken off, leaves a roughness that
         requires to be removed. The fine lines at the top and
         bottom of a letter are technically called ceriphs, and
         when part of the face projects over the body, as in the
         letter f, the projection is called a kern. The type
         which compose an ordinary book font consist of Roman
         CAPITALS, small capitals, and lower-case letters, and
         Italic CAPITALS and lower-case letters, with
         accompanying figures, points, and reference marks, --
         in all about two hundred characters. Including the
         various modern styles of fancy type, some three or four
         hundred varieties of face are made. Besides the
         ordinary Roman and Italic, some of the most important
         of the varieties are -- Old English. Black Letter. Old
         Style. French Elzevir. Boldface. Antique. Clarendon.
         Gothic. Typewriter. Script. The smallest body in common
         use is diamond; then follow in order of size, pearl,
         agate, nonpareil, minion, brevier, bourgeois (or
         two-line diamond), long primer (or two-line pearl),
         small pica (or two-line agate), pica (or two-line
         nonpareil), English (or two-line minion), Columbian (or
         two-line brevier), great primer (two-line bourgeois),
         paragon (or two-line long primer), double small pica
         (or two-line small pica), double pica (or two-line
         pica), double English (or two-line English), double
         great primer (or two-line great primer), double paragon
         (or two-line paragon), canon (or two-line double pica).
         Above this, the sizes are called five-line pica,
         six-line pica, seven-line pica, and so on, being made
         mostly of wood. The following alphabets show the
         different sizes up to great primer. Brilliant . .
         abcdefghijklmnopqrstuvwxyz

Carbureted \Car"bu*ret`ed\, a.
   1. (Chem.) Combined with carbon in the manner of a carburet
      or carbide.

   2. Saturated or impregnated with some volatile carbon
      compound; as, water gas is carbureted to increase its
      illuminating power. [Written also {carburetted}.]

   {Carbureted hydrogen gas}, any one of several gaseous
      compounds of carbon and hydrogen, some of with make up
      illuminating gas.

   {Light carbureted hydrogen}, marsh gas, {CH4}; fire damp



   {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.

Homology \Ho*mol"o*gy\, n. [Gr. ? agreement. See {Homologous}.]
   1. The quality of being homologous; correspondence; relation;
      as, the homologyof similar polygons.

   2. (Biol.) Correspondence or relation in type of structure in
      contradistinction to similarity of function; as, the
      relation in structure between the leg and arm of a man; or
      that between the arm of a man, the fore leg of a horse,
      the wing of a bird, and the fin of a fish, all these
      organs being modifications of one type of structure.

   Note: Homology indicates genetic relationship, and according
         to Haeckel special homology should be defined in terms
         of identity of embryonic origin. See {Homotypy}, and
         {Homogeny}.

   3. (Chem.) The correspondence or resemblance of substances
      belonging to the same type or series; a similarity of
      composition varying by a small, regular difference, and
      usually attended by a regular variation in physical
      properties; as, there is an homology between methane,
      {CH4}, ethane, {C2H6}, propane, {C3H8}, etc., all members
      of the paraffin series. In an extended sense, the term is
      applied to the relation between chemical elements of the
      same group; as, chlorine, bromine, and iodine are said to
      be in homology with each other. Cf. {Heterology}.

   {General homology} (Biol.), the higher relation which a
      series of parts, or a single part, bears to the
      fundamental or general type on which the group is
      constituted. --Owen.

   {Serial homology} (Biol.), representative or repetitive
      relation in the segments of the same organism, -- as in
      the lobster, where the parts follow each other in a
      straight line or series. --Owen. See {Homotypy}.

   {Special homology} (Biol.), the correspondence of a part or
      organ with those of a different animal, as determined by
      relative position and connection. --Owen.