metamericadj.1
/ˌmɛtəˈmɛrɪk/, U.S. /ˌmɛdəˈmɛrɪk/ 1. Chemistry. Of two or more compounds: having the same percentage composition and molecular weight, but differing in molecular arrangement and chemical properties; isomeric, with different functional groups. Also: sharing the same empirical formula and molecular weight with another compound. Now rare.
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the world > matter > chemistry > isomerism > [adjective] > of or relating to structural isomerism > of or relating to functional group isomerism > specifically of metamerism
metameric1833
1833 Rep. 1st & 2nd Meetings Brit. Assoc. Advancem. Sci. 1831–2 435 To designate compounds approaching in atomic constitution very nearly to those properly called Isomeric, Berzelius has proposed the introduction of two new terms, polymeric and metameric.
1847 Turner's Elem. Chem. (ed. 8) i. 176 Where two compounds are isomeric, the atoms must be differently grouped, if the equivalents are equal... Taking this circumstance into consideration, compounds thus related are strictly called metameric.
1865 Jrnl. Chem. Soc. 18 142 The decomposition which the acid suffers when heated with potassium hydrate, proves that it is metameric, and not identical with ethylic crotonate.
1877 H. Watts Dict. Chem. (new ed.) V. 161 This body, metameric with chlorosalicylol.., is produced [etc.]
1907 G. S. Newth Text-bk. Inorg. Chem. (ed. 12) 194 They [sc. acetone and allyl alcohol] have the same molecular weight and the same percentage composition, but belong to widely different types of compounds; they are therefore called metameric compounds.
1994 Org. Mass Spectrometry 29 347/1 Our investigations have now been extended to mass spectral fragmentation of N-(E)-stilbenyloxyalkylcarbonyl-substituted amino acids and their metameric derivatives.
2. Optics. Of, relating to, or designating colours or other stimuli that are metamers (metamer n.1 2); exhibiting or relating to metamerism (metamerism n.1 2).
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1931–3 J. S. Taylor tr. W. Ostwald Colour Sci. II. v. 35 Metameric Colours may exist, i.e. Colours which appear precisely the same, but are different in their physical composition.
1945 Jrnl. Optical Soc. Amer. 35 199/1 It is possible also to produce a color match between lights of different spectral compositions; such lights are called metamers, and are said to form metameric pairs.
1969 Vision Res. 9 677 If the different light mixtures are metameric, i.e. if they appear equal to the observer.
1985 Color Res. & Applic. 10 106 The method also can be used to predict the degree of mismatch found by color-normal observers for pairs of reflecting samples that are a metameric match with respect to the average observer and a standard illuminant.
1999 Prosthetics & Orthotics Internat. 23 174/1 This metameric colour difference can be minimised if the prosthesis is matched under a combination of lights.
This entry has been updated (OED Third Edition, December 2001; most recently modified version published online March 2022).
metamericadj.2
/ˌmɛtəˈmɛrɪk/, U.S. /ˌmɛdəˈmɛrɪk/ Zoology and Botany.
Exhibiting metamerism (metamerism n.2); of, relating to, or characterized by metamerism; of the nature of a metamere or metamer.
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the world > animals > animal body > general parts > [adjective] > segmented > relating to metameres
metameric1875
metamerous1887
metameral1890
1875 tr. E. O. Schmidt Doctr. Descent & Darwinism (ed. 2) 54 The metameric formation, as it is termed by Haeckel,—is totally foreign to the Molluscs.
1901 Trans. Linn. Soc.: Zool. 8 259 In all cases it appears to have more autonomy; that is to say, to be in less intimate connection with the metameric spinal nerves than in most other vertebrate forms.
1939 T. L. Green Pract. Animal Biol. ii. 216 Behind the first ventral primary gill slit a series of about fourteen is developed each lying in a single metameric segment.
1962 T. G. Hiebert Abbrev. Basic Med. Physiol. (ed. 4) i. iv. 25 Dermatomes..generally follow the metameric distribution of the posterior root fibers.
1995 C. Nielsen Animal Evol. xii. 99 The metameric spiralians (annelids and panarthropods) have often been united in a group called articulates.
This entry has been updated (OED Third Edition, December 2001; most recently modified version published online March 2022).
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adj.11833adj.21875