| 释义 |
plumbago|plʌmˈbeɪgəʊ|
Also 7 plumbage, 8 plombago.
[a. L. plumbāgo a species of lead ore, also a plant, leadwort, fleawort (Pliny): in both senses rendering Gr. µολύβδαινα of Dioscorides, deriv. of µόλυβδος lead. For the original meaning and complicated history of the word, see note below.]
†1. Applied to the yellow oxide of lead (litharge); also sometimes to the sulphide (galena); and (in quot. 1612) app. to minium or red oxide of lead, obtained from litharge by further oxidation. Obs.
1612Woodall Surg. Mate Wks. (1653) 77 Plumbago, or red lead, hath the force of binding. 1661Lovell Hist. Anim. & Min. 38 Plumbage [L.] Plumbago. P[lace] It sticks to the furnace in the purifying of silver or gold. M[atter] of Silver or Gold purified with lead. N[ame] Μολύβδαινα Molybdæna..it's like litharge in vertue. 1669Rowland tr. Schroder's Med.-Chem. Pharmacop. xix. 245–6 Molybdena or Plumbago. It is natural or artificial: the first is Lead Ore or that mixed with silver. The artificial is a kind of Litharge, that sticks to the bottom of the Furnace [etc.].
2. Min. Black lead or graphite; one of the allotropic forms of carbon: used for pencils, also, mixed with clay, for making crucibles; and for many other purposes.
‘Black lead’ is the popular, and ‘graphite’ the strictly scientific name; but the term ‘plumbago’ is largely used in the arts, esp. in mining.
1784Kirwan Elem. Min. 158 Plumbago, Reissbley..Blyertz of the Swedes... In a strong heat and open fire it is wholly volatile. 1786tr. Scheele's Chem. Ess. 243 The black lead or plumbago which is generally known in commerce, is very different from molybdæna. Ibid. 250 Hence I am convinced, that plumbago is a kind of mineral sulphur or charcoal; the constituent parts of which are aerial acid and a considerable quantity of phlogiston. 1788Cronstedt's Min. (ed. 2) II. 451 Black lead or plumbago is a fossil substance extremely black. 1795Pearson in Phil. Trans. LXXXV. 335 The black matter was therefore a compound of iron and carbon, or, as some chemists term it, plumbago; and which in the new system is denominated a carburet of iron. 1796Kirwan Elem. Min. (ed. 2) II. 58 Plumbago. Graphite of Werner..carbon combined with one tenth or one eighth of its weight of malleable iron. 1799― Geol. Ess. 191 Probably because the iron..had absorbed too great a quantity of carbon, and was thus converted into plombago. 1808Henry Epit. Chem. (ed. 5) 242 Another combination of iron and carbon, which is a true carburet of iron, is the substance called plumbago, or black-lead, used in fabricating pencils, and in covering iron to prevent rust. [So1815(ed. 7) II. 120.] 1843W. Humble Dict. Geol. (ed. 2) 32/1 Anthracite resembles and appears to pass into plumbago. 1846McCulloch Acc. Brit. Empire (1854) I. 619 That very rare mineral called black lead, plumbago, or wad, is found in Borrowdale, in Cumberland. The mines in this place have been wrought since the days of Queen Elizabeth, and furnish the very best material hitherto discovered for making pencils. 1869Roscoe Elem. Chem. (1871) 82 Graphite, or Plumbago, crystallizes in six-sided plates.
3. Bot. A genus of herbaceous plants, inhabiting Southern Europe, Asia, Africa, and America, having spikes of subsessile flowers, with a tubular five-parted calyx; leadwort: so called from the colour of the flowers. [Pliny's name (rendering Gr. Μολύβδαινα), adopted as generic name by Tournefort, 1700.] Also attrib.
[1601Holland Pliny II. 336 There groweth commonly an herbe named in Greeke Molybdæna, that is to say in Latine, Plumbago, euen vpon euery corne land.] 1747Wesley Prim. Physic (1762) 42 Infusion of Leaves of Plumbago in Olive Oil. 1776Lee Introd. Bot. App. (ed. 3) 337 Leadwort, Plumbago. 1877J. A. Chalmers Tiyo Soga vi. 53 He distributed twigs from the plumbago plant to be worn round the neck. 1903Contemp. Rev. Mar. 346 Pale blue plumbagos, yellow canariensis. [Note. In Dioscorides, µολύβδαινα, f. µόλυβδος lead, was applied to a mineral substance (v. 97, 100), and a plant. The former was yellow oxide of lead (PbO), esp. the litharge produced in the extraction of gold and silver from ores containing lead. By Pliny this is latinized as molybdæna, also once (xxxiv. 18. 50) by plumbāgo, which, as well as galēna, were applied by him to the yellow oxide, but prob. included as an inferior variety the sulphide (PbS), called by Dioscorides µολυβδοειδὴς λίθος, ‘lead-like stone’, the modern galena. For the plant Pliny always uses plumbago. In the French transl. (1572) of Matthioli's Commentary on Dioscorides, µολύβδαινα = plumbago is rendered plombagine, in It. piombaggine, and is stated to be identical with litharge; but other ores may have been included. Thence the explanations of the word in Cotgrave and other English writers down to Bailey: see plumbagine, and sense 1 above. In Holland's Pliny, plumbago is rendered litharge. In the 16th c., to Agricola and others in Germany practically interested in mining, plumbago mainly meant the sulphide of lead, but also included other substances similar to this in appearance, and in the property of staining the fingers and marking paper, esp. the native sulphides of antimony and molybdenum, stibnite (Sb2S3) and molybdenite (MoS2), and the mineral graphite. In 1567 Christoph. Enkel (Encelius) of Saalfeld, while identifying Pliny's molybdæna, galēna, and plumbāgo, distinguished the ‘productive’ species (i.e. the oxide and sulphide of lead) from the ‘barren’ (sterilis), which yielded no lead, and was mainly graphite; the latter was described by Ferrante Imperato in 1599 as employed in the grafio piombino, ‘leaden pencil’. In 1779 Scheele found that certain samples of the ‘barren’ plumbago, on being burnt, were dissipated into carbonic acid gas, and that in fact they consisted of carbon: see quot. 1786 in sense 2. In 1789 Werner and Karsten proposed the name graphite instead of the ambiguous ‘plumbago’. But its composition was still disputed. An analysis, made by French chemists in 1786, had given, after volatilization, a residue of iron, and plumbago was pronounced a carburet of iron (see quot. 1795). This view prevailed until Karsten in 1826 and Sefström in 1829 proved that the iron was only an impurity in the specimens analysed, and that graphite or plumbago was, as Scheele had said in 1779, really a mineral form of carbon. (See paper by Dr. John W. Evans, F.G.S., in Trans. Phil. Soc. 1907.)]
Add:[2.] b. Used attrib. of drawings, esp. miniatures, made with a plumbago or ‘lead’ pencil. Chiefly Hist.
1904G. C. Williamson Hist. Portrait Miniatures I. iv. 61 It is a very dainty piece of plumbago work. 1963D. Foskett Brit. Portrait Miniatures i. 38 Plumbago miniatures were in vogue from about 1660–1720. 1976Times 30 Mar. 19/4 A fine plumbago miniature of Charles II by Robert White, dated 1678. |