[ad. L. type *spectrāl-is, f. spectrum SPECTRE and SPECTRUM. So mod.F. spectral.]
† 1. Capable of seeing spectres. Obs.
1718. Bp. Hutchinson, Witchcraft, v. 81. Joseph Ballard … sent to Salem, for some of these Accusers, who pretended to have the spectral Sight, to tell him who afflicted his Wife.
2. Having the character of a spectre or phantom; ghostly, unsubstantial, unreal.
1815. Shelley, Alastor, 259. The mountaineer, Encountering on some dizzy precipice That spectral form.
1818. Scott, Br. Lamm., xiii. Some of the spectral appearances which he had heard told of in a winter’s evening.
1853. Kane, Grinnell Exp., xxxiv. (1854), 307. The setting sun … gave us again the spectral land about Cape Adair, eighty miles off.
1877. Black, Green Past., xlii. We saw through a window a wild vision of a pair of spectral horses apparently in mid-air.
fig. 1829. I. Taylor, Enthus., viii. 191. A spectral resemblance of piety, unsubstantial and cold as the mists of night.
1837. Dickens, Pickw., xxiv. A spectral attempt at drollery.
Comb. 1840. Mrs. S. C. Hall, Irish Peasantry (1850), 133. A lean, spectral-looking gray horse … limped towards them.
1868. Boyd, Less. Middle Age, 315. A mile or two down,… tall and spectral-white, stands the Cloch lighthouse.
b. Resembling, looking like, suggestive of, a spectre or spectres. Also spec. in Zool.
1828. Lytton, Pelham, I. xviii. 138. The spectral secretary of the embassy.
1843. Bethune, Scott. Peasant’s Fire-side, 110. That species of erect tombstone, which some one has somewhere designated ‘spectral.’
1851. Ruskin, Stones Ven. (1874), I. App. 366. The old spectral Lombard friezes.
1884. Coues, N. Amer. Birds, 509. Strix cinerea,… Spectral Owl.
1896. H. O. Forbes, Hand-bk. Primates, I. 20. The Spectral Tarsier.
3. Characteristic of, appropriate to, a spectre.
1820. Byron, Mar. Fal., V. ii. They form’d a spectral voice, Which shook me in a supernatural dream.
1852. Mrs. Jameson, Leg. Madonna, Introd. (1857), 25. Compared with the spectral rigidity, the hard monotony, of the conventional Byzantines.
1898. Watts-Dunton, Aylwin, I. vi. (1899), 30. Crumbling cliffs, whose jagged points and indentations had the kind of spectral look peculiar to that coast.
4. Produced merely by the action of light on the eye or on a sensitive medium.
1839. G. Bird, Nat. Phil., 398. If the wafer were yellow, and placed on a black surface, the spectral image will be deep violet when viewed on a white ground; in the same manner a white wafer is attended by its black spectral figure.
5. a. Of or pertaining to, appearing or observed in, the spectrum.
1832. Nat. Philos. (L.U.K.), II. Index 40. Spectral colours, when re-united, produce white.
1849. Mrs. Somerville, Connex. Phys. Sci. (ed. 8), xxiv. 235. A spectral image obtained by Mr. Hunt on a similar [Daguerreotype] plate.
1866. Atkinson, trans. Ganot’s Physics (ed. 2), § 480. 424. The relative distances of the different spectral lines.
1879. Rood, Mod. Chromatics, x. 127. By mixing three or more spectral colours no new hues were produced.
1883. R. A. Proctor, in 19th Cent., Nov., 881. Its absorptive capacity for particular spectral tints.
b. Carried out or performed by means of the spectrum. Freq. in spectral analysis.
1862. Amer. Jrnl. Sci., Nov., 404. There are few branches of science which promise more magnificent results than the spectral analysis.
1879. Proctor, Pleas. Ways Sci., i. 26. The inquiry seems specially suited to the methods of spectral photography pursued by Dr. Draper.
1881. Times, 10 March, 11/6. Spectral observations on stars.
Hence Spectralism, a spectral or ghostly scene. Spectrality, a phantasm; ghostliness. Spectrally adv., in a ghostly manner. Spectralness, the quality or character of being spectral.
1851. Carlyle, in New Rev. (1891), Oct., 299. All dreamlike, one *spectralism succeeding another. Ibid. (1850), Latter-d. Pamph., i. 50. Traditions now really about extinct;… still haunting with their *spectralities … almost all of us!
1880. Scribner’s Mag., July, 326. There is about it a certain vagueness and spectrality.
1837. Carlyle, Fr. Rev., II. II. vi. This … did for many months, walk *spectrally,—in all French heads.
1865. Dickens, Mut. Fr., III. ii. The steamer’s lights moved spectrally a very little.
1892. W. W. Peyton, Memorab. Jesus, x. 285. A *spectralness, which … gives you an idea of weirdness.
