before a vowel leuc-, a. Gr. λευκο-, combining form of λευκός white, as in Leucaniline Chem., a white crystalline coal-tar base (C20H21N3) obtained from rosaniline by reduction and from other substances. Leucanthous a. Bot. [Gr. ἄνθ-ος flower + -OUS], white-flowered (Mayne, Expos. Lex., 1855). Leucaugite Min. [AUGITE], a white or greyish variety of augite (Dana, 1868). Leucoblast Biol. [-BLAST], one of the spheroidal cells from which leucocytes develop. Leucocholy nonce-wd. [after MELANCHOLY] (see quot.). Leucocyclite Min. [Gr. κύκλ-ος + -ITE], a synonym of apophyllite. ǁ Leucoderma Path. [Gr. δέρμα skin], deficiency of coloring matter or unnatural whiteness in the skin; hence Leucodermic a. (Cent. Dict.). ǁ Leucomelanous a. [Gr. μελαν-, μέλας + -OUS], having a fair complexion with dark hair. Leucopenia Path. [Gr. πενία poverty] (see quot.); hence Leucopenic a., characterized by leucopenia. Leucophyll Bot. [Gr. φύλλ-ον leaf], a colorless substance found in the corpuscles of an etiolated plant, capable of being transformed into chlorophyll. ǁ Leucoplacia Path. [Gr. πλακ-, πλάξ a flat surface], white patches appearing on the tongue or on the mucous membrane within the mouth. Leucoplast Biol. [Gr. πλαστ-ός moulded] = next. Leucoplastid Biol. [PLASTID], one of the colorless corpuscles found in the protoplasm of vegetable cells around which starch accumulates. Leucoscope [-SCOPE], an instrument contrived by Helmholtz for comparing the relative whiteness of lights or colors, or for testing the power of the eye to distinguish colors. Leucospermous a. Bot. [Gr. σπέρμα seed + -OUS], having white seeds. Leucosphere Astron. [SPHERE], the inner corona. Leucoxene Min. [Gr. ξένος guest], a white decomposition product of titanic iron; probably titanite (Cent. Dict.).
1863. Fownes’ Chem., 673. The action of sulphide of ammonium upon rosaniline gives rise to a base *leucaniline which contains two additional equivalents of hydrogen.
1901. Brit. Med. Jrnl., 29 June, 1606. A partial exhaustion of the *leucoblastic function of the bone marrow.
1742. T. Gray, Lett., 27 May, Wks. 1884, II. 113. Mine … is a white Melancholy, or rather *Leucocholy, for the most part; which, though it seldom laughs or dances, nor ever amounts to what one calls Joy or Pleasure, yet is a good easy sort of a state.
1829. Nat. Philos., Polaris. Light, ix. 34 (U. K. S.). In other specimens of apophyllite, which Mr. Herschel calls *leucocyclite, from the rings being white and black.
1884. Max Müller, in 19th Cent., June, 1017. A semi-human progenitor, suffering, it may be, from leprosy or *leucoderma.
1898. Allbutt’s Syst. Med., V. 418. Any number of leucocytes below the arbitrary limit of 6000 [per cubic millimetre of blood] will constitute a hypoleucocytosis, or *leucopenia as the condition is also named. Ibid., 420. He was able to distinguish … a *leucopenic phase, or hypoleucytosis, during which the number of hæmic leucocytes falls [etc.].
1865. Watts, Dict. Chem., III. 584. *Leucophyll.
1885–8. Fagge & Pye-Smith, Princ. Med. (ed. 2), I. 124. A similar affection of the tongue often follows *leucoplacia, or white syphilitic patches, at the end of several years.
1885. Goodale, Physiol. Bot. (1892), 43. *Leucoplastids … are found in parts which are normally devoid of chlorophyll, such as tubers, rhizomes, etc.
1883. Nature, XXVII. 277. Professor Helmholtz’s new instrument, called the *leukoscope.
1871. trans. Schellen’s Spectr. Anal., lvi. 272. For this envelope the name *‘leucosphere’ has been proposed.
