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CH4

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.

CH4

Methane \Meth"ane\, n. [See Methal.] (Chem.) A light, colorless, gaseous, inflammable hydrocarbon, CH4; marsh gas. It is the simplest of the aliphatic hydrocarbons. 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.

CH4

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:

    1. (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.

    2. (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.

    3. (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.)

    1. A raised letter, figure, accent, or other character, cast in metal or cut in wood, used in printing.

    2. 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 t`e 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. [1913 Webster] 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 [1913 Webster] Old English. Black Letter. Old Style. French Elzevir. Boldface. Antique. Clarendon. Gothic. Typewriter. Script. [1913 Webster] 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. [1913 Webster] Brilliant . . abcdefghijklmnopqrstuvwxyz Diamond . . abcdefghijklmnopqrstuvwxyz Pearl . . . abcdefghijklmnopqrstuvwxyz Agate . . . abcdefghijklmnopqrstuvwxyz Nonpareil . . . abcdefghijklmnopqrstuvwxyz Minion . . . abcdefghijklmnopqrstuvwxyz Brevier . . . abcdefghijklmnopqrstuvwxyz Bourgeois . . abcdefghijklmnopqrstuvwxyz Long primer . . . abcdefghijklmnopqrstuvwxyz Small pica . . abcdefghijklmnopqrstuvwxyz Pica . . . . . abcdefghijklmnopqrstuvwxyz English . . . abcdefghijklmnopqrstuvwxyz Columbian . . . abcdefghijklmnopqrstuvwxyz Great primer . . . abcdefghijklmnopqrstuvwxyz [1913 Webster] The foregoing account is conformed to the designations made use of by American type founders, but is substantially correct for England. Agate, however, is called ruby, in England, where, also, a size intermediate between nonpareil and minion is employed, called emerald.

      Point system of type bodies (Type Founding), a system adopted by the type founders of the United States by which the various sizes of type have been so modified and changed that each size bears an exact proportional relation to every other size. The system is a modification of a French system, and is based on the pica body. This pica body is divided into twelfths, which are termed ``points,'' and every type body consist of a given number of these points. Many of the type founders indicate the new sizes of type by the number of points, and the old names are gradually being done away with. By the point system type founders cast type of a uniform size and height, whereas formerly fonts of pica or other type made by different founders would often vary slightly so that they could not be used together. There are no type in actual use corresponding to the smaller theoretical sizes of the point system. In some cases, as in that of ruby, the term used designates a different size from that heretofore so called. [1913 Webster] 1 American 9 Bourgeois [bar] [bar] 11/2 German [bar] 2 Saxon 10 Long Primer [bar] [bar] 21/2 Norse [bar] 3 Brilliant 11 Small Pica [bar] [bar] 31/2 Ruby 12 Pica [bar] [bar] 4 Excelsior [bar] 41/2 Diamond 14 English [bar] [bar] 5 Pearl 16 Columbian [bar] [bar] 51/2 Agate [bar] 6 Nonpareil 18 Great Primer [bar] [bar] 7 Minion [bar] 8 Brevier 20 Paragon [bar] [bar] Diagram of the "points" by which sizes of Type are graduated in the "Point System".

      Type founder, one who casts or manufacture type.

      Type foundry, Type foundery, a place for the manufacture of type.

      Type metal, an alloy used in making type, stereotype plates, etc., and in backing up electrotype plates. It consists essentially of lead and antimony, often with a little tin, nickel, or copper.

      Type wheel, a wheel having raised letters or characters on its periphery, and used in typewriters, printing telegraphs, etc.

      Unity of type (Biol.), that fundamental agreement in structure which is seen in organic beings of the same class, and is quite independent of their habits of life.
      --Darwin.

CH4

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, methane ( CH4), also called marsh gas, and fire damp.

Wiktionary
ch4

n. (abbreviation of http://en.wikipedia.org/wiki/Channel%204 English)

Wikipedia
CH4 (disambiguation)

CH4 most commonly refers to the chemical compound methane.

It may also refer to:

  • a postcode subdistrict of Chester, United Kingdom
  • the METHANE emergency service mnemonic
  • the CH-4 variant of the Cessna CH-1 Skyhook helicopter
  • the CH-4 variant of the CASC Rainbow unmanned aerial vehicle