| 释义 |
magnesia|mægˈniːʃ(ɪ)ə|
Also 4 magnasia, 5 magnetia.
[a. med.L. magnēsia, a. Gr. ἡ Μαγνησία λίθος, ‘the Magnesian stone’, a designation of two different minerals: (1) the loadstone; (2) a stone shining like silver, perhaps talc (Liddell & Scott).
It is not clear which of these two senses gave rise to the alchemical use; the brilliant lustre ascribed by the alchemists to ‘magnesia’ favours the latter view, and the substance seems not to have been identified with the loadstone, in spite of the resemblance of its name to the familiar word Magnes.]
†1. Alchemy. A mineral alleged by some alchemists to be one of the ingredients of the philosopher's stone. Obs.
c1386Chaucer Can. Yeom. Prol. & T. 902 Take the stoon that Titanos men name. Which is that quod he. Magnasia is the same, Seyde Plato. Ibid. 905 What is Magnasia, good sire, I yow preye. It is a water that is maad, I seye, Of elementes foure, quod Plato. 1472Ripley Comp. Alch. Pref. in Ashm. (1652) 133 Our Stone ys callyd the lesse World one and three, Magnesia also of Sulphure and Mercury Proportionate by Nature most perfytly. 1477Norton Ord. Alch. iii. ibid. 42 Another Stone..you must have withall..A Stone glittering with perspecuitie..The price of an Ounce Conveniently Is twenty shillings;..Her name is Magnetia, few people her knowe. 1610B. Jonson Alch. ii. iii, Your marchesite, your tutie, your magnesia.
fig.1651Biggs New Disp. Pref. b 2 b, We catch at onely painted Butter-flyes, and speculate not the Magnesia or substantiality of Physicks, but rather its Umbrage; not the Body, but the Bark, and superficial out side.
†b. Used by Paracelsus for: amalgam. Obs.
1641French Distill. vi. (1651) 185 Hang plates of gold over the fume of Argent vive, and they will become white, friable, and fluxil as wax. This is called the Magnesia of gold, as saith Paracelsus.
†2. = manganese 1. Also black magnesia. Obs.[This use prob. arose from the notion that manganese was a form of the ‘magnesia’ of alchemy. There may, however, have been some early confusion of manganese with loadstone: Pliny N. H. xxxvi. lxvi says that loadstone (magnes lapis) was used in making glass. In the Latin of early chemistry the word was applied to various other substances: e.g. magnesia opalina was a red sulphide of antimony (? = kermes 3).] 1677Plot Oxfordsh. 79 Magnesia (in the Glass-houses, called Manganese). 1712tr. Pomet's Hist. Drugs I. 103/2 The last ingredient [sc. of Cristalline Glass] is Manganese, or Magnesia, so called from its Likeness in Colour, Weight and Substance to the Load-Stone. 1753Chambers Cycl. Supp. s.v. Magnissa, Many have supposed the Magnissa to be the same with magnesia, that is, manganese, but this is an error. 1797Encycl. Brit. (ed. 3) X. 427/1 Black Magnesia. See Manganese.
3. (In early use often † white magnesia = mod.L. magnesia alba, in contradistinction to black magnesia: see 2.)
a. Originally, and still in popular language, applied to hydrated magnesium carbonate, a white earthy powder, used in medicine as an antacid and cathartic. calcined magnesia: magnesium oxide (pure ‘magnesia’: see b) prepared by heating the carbonate.
b. In modern Chem., an alkaline earth, now recognized as the oxide of magnesium (MgO).[This application of the word seems not to be connected with the use in sense 1, but to have been suggested by the mod.L. magnes carneus ‘flesh-magnet’, applied c 1550 by Cardan (De Subtilitate vii, Opera III. 475) to a white earth resembling osteocolla, because it was found to adhere strongly to the lips, and was therefore supposed to have the same attraction for flesh that the loadstone has for iron. The mod.L. term magnesia alba seems to have been first employed by Hoffmann in 1722 (Opera 1740 IV. 479/2).] 1755J. Black Exper. Magnesia Alba etc. (1893) 7, I have had no opportunity of seeing Hoffman's first magnesia. Ibid. 8 Those who would prepare a magnesia from Epsom salt may use the following process. 1794Sullivan View Nat. I. 240 It exists in a state of combination, in lime-stone, common magnesia, alkalis, &c. 1799Med. Jrnl. II. 206 Magnesia has long been a celebrated remedy for these [stomachic] complaints. 1812Sir H. Davy Chem. Philos. 48 Hoffman, in the beginning of the 18th century, pointed out magnesia as a peculiar substance. 1823Byron Juan x. lxxiii, These sodas and magnesias Which form that bitter draught, the human species. 1878Huxley Physiogr. 80 The metal combines with the oxygen of the air to form oxide of magnesium or magnesia.
c. attrib.
1846G. E. Day tr. Simon's Anim. Chem. II. 133 The magnesia salts would..answer this purpose better. 1876Preece & Sivewright Telegraphy 34 A solution of the magnesia sulphate (MgSO4. Epsom salts). |