Forms: 4 alem, 4–5 alym, 4–8 alom, 5–7 alume, alome, 6 alme, 6–7 allume, 6–8 allom(e, allum, 4– alum. [a. OFr. alum:—L. alūmen, the same substance: cf. alūta tawed skin.]
1. A whitish transparent mineral salt, crystallizing in octahedrons, very astringent, used in dyeing, tawing skins, and medicine, also for sizing paper, and making materials fireproof; chemically a double sulphate of aluminium and potassium (AlK(SO4)2 + 12H2O water of crystallization).
Burnt Alum, A. deprived of its water of crystallization so as to become a white powder; Rock or Roman Alum, that prepared from the Alum-stone in Italy; Saccharine Alum, an artificial composition of alum, rosewater, and egg albumen, boiled to a paste, which hardens when cold.
c. 1325. E. E. Allit. P., B. 1035. As alum & alka[t]ran, that angré arn boþe.
1366. Maundev., ix. 99. About that see growethe moche Alom.
c. 1386. Chaucer, Chan. Yem. Prol., 260. Tartre, alym, glas [v.r. alum, alumglas(se, alem].
1436. Pol. Poems, 11. 172. Coton, roche-alum, and gode golde of Jene.
1453. in Heath, Grocers’ Comp. (1869), 422. Alum, foyle or rooch, ye bale … iiijd.
1551. Turner, Herbal, II. (1568), 123. Layed to with honey and allome.
1585. James I., Ess. Poesie, 16. Cleare and smothe lyke glas or alme.
1587. Holinshed, Chron., III. 1199/1. A mightie great hulke, laden with wood & allume.
1601. Holland, Pliny (1634), II. 559. Alume brought from Melos, is the best.
1622. Heylyn, Cosmogr., I. (1682), 75. Well furnished with Allom, Sulphur, and Bitumen.
1660. R. Coke, Power & Subj., 208. The Pope had excommunicated all persons whatsoever, who had bought alume of the Florentines.
1671. Salmon, Syn. Med., III. xxii. 437. A lotion with Honey, Alome, and White wine.
1703. Moxon, Mech. Exerc., 238. A fat Earth full of Allom.
1718. Mrs. Eales, Receipt, 38. Put in a good piece of Roach-Allum.
1718. Quincy, Compl. Disp., 106. Alum is dug out of the earth as we find it in the Shops.
1768. Boswell, Corsica, i. (ed. 2), 52. There are also mines of allum.
1815. Bakewell, Introd. Geol., 201. The sulphuric acid uniting with the alumine, forms the well-known salt called alum.
1855. Tennyson, Maud, I. i. x. While chalk and alum and plaster are sold to the poor for bread.
1875. Ure, Dict. Arts, I. 105. [Alum] seems to have come to Europe in later times as alum of Rocca, the name of Edessa; but it is not impossible that this name was an Italian prefix, which has remained to this day under the name of Rock Alum, Allume di Rocca.
2. Mod. Chem. (with pl.) A series of isomorphous double salts, including the foregoing, consisting of aluminium sulphate in combination with the sulphate of a monatomic metal, as potassium, sodium, ammonium, silver, etc., with general formula Al″M(SO4)2 + 12H2O; all of which crystallize in octahedrons: distinguished as Common or Potash alum, Soda alum, Ammonia alum, Silver alum, etc.
1868. Watts, Dict. Chem., V. 580. Argento-aluminic sulphate or Silver alum. Potassio-aluminic sulphate or Potash-alum: this is the salt to which the name alum is most generally applied.
1873. Williamson, Chem., § 185. These alums cannot be separated by crystallization; and a crystal of one of them grows regularly in a solution of another alum.
1873. Fownes, Chem., 373. Sodium alum is much more soluble.
1875. Ure, Dict. Arts, I. 107. The composition of potash-, soda-, and ammonia-alums found ready formed in nature.
3. Mod. Chem. (with pl.) Extended to a family of compounds analogous to and including the preceding series, in which the Alumina itself is absent, and replaced by the isomorphous sesquioxide of iron, chrome, or manganese; whence Iron alum (Potassio-ferric sulphate), Manganese alum (Potassio-manganic sulphate), Chrome alum (Potassio-chromic sulphate), Chrome-ammonia alum (Ammonio-chromic sulphate), etc.
1868. Watts, Dict. Chem., V. 578. The dodecahydrated double sulphates of the alkali-metals and triatomic metals constitute the true alums. The sulphates of ammonium, potassium, and sodium are capable of forming alums with the aluminic, ferric, chromic, and manganic sulphates.
1874. Roscoe, Elem. Chem., 247. Chromium sulphate forms a series of alums with potassium and ammonium sulphates, which have a deep purple tint, and are isomorphous with common alum.
4. Min. Applied to various native minerals, which are chemically alums proper, as Native alum or Kalinite; also to others (pseudo-alums), which are compounds of aluminium sulphate with the sulphate of some other base, as Magnesia alum (Magnesio-aluminic sulphate) or Pickeringite; or with the protoxides of iron, manganese, etc., as Feather or Plume alum (Ferroso-aluminic sulphate) or Halotrichite, Manganese alum or Apjohnite, Manganoso-magnesian alum or Bosjemanite.
The name Feather alum has been applied also to magnesia alum and alunogen.
a. 1661. Holyday, Juvenal (1673), 122. Plume-alume burns the skin … rock-alume dissolves metals, shrivels the skin, loosens the teeth.
1868. Dana, Min., 655. Hallotrichine is a silky alum from the Solfatara near Naples.
1868. Watts, Dict. Chem., V. 583. Manganoso-aluminic sulphate, or manganese alum … occurs in snow-white silky fibres at Lagoa Bay.
5. Comb., in which alum stands in obj. relation to pr. pple. or vbl. sb., as alum-bearing, -maker, -making, -manufacture; in instrumental relation to pa. pple., as alum-steeped; in simple attrib. relation, as alum-crystal, -liquor, -water; or attrib. relation of material, as alum-styptic.
1869. Roscoe, Elem. Chem., 215. Ammonium Sulphate is largely employed for alum making.
1870. Yeats, Nat. Hist. Comm., 381. The chief localities of alum manufacture in this country.
1837. Syd. Smith, Lett., Wks. 1859, II. 277/1. Let him drive his alum-steeped loaves a little further.
1587. Harrison, England, I. II. xxiii. 348. A tast much like to allume liquor.
1875. Ure, Dict. Arts, I. 117. Alum Liquors,—In the alum works on the Yorkshire coast, eight different liquors are met with.
1578. Lyte, Dodoens, VI. xxx. 697. Soked, or delayed in allom water.
1656. Du Gard, Lat. Unlocked, § 443. Hee wetteth with allom-water every sheet of thinner paper.
1711. Pope, Rape Lock, II. 131. Alom-stypticks with contracting pow’r Shrink his thin essence like a rivelled flow’r.
Also alum cake, a massive and porous sulphate of alumina, mixed with silica, manufactured from fine clay; alum earth, applied to various earthy or loose substances yielding alum; † alum-farmer, one who farmed the royal alum-works; † alum-flower, alum calcined and powdered; † alum-glass, crystallized alum; alum-rock, -schist, -shale, -slate, thin-bedded rocks found in various formations, from which alum is manufactured; alum-stone, the mineral ALUNITE, from which the Rock or Roman alum is made; alum-works, the place and apparatus for making alum. Also ALUM-ROOT, q.v.
1612. Speed, Theat. Gt. Brit., xli. 81/1. An allum-earth of sundry colours.
1641. in 4th Rep. Hist. MSS. (1874), 71/1. Account of the sums for which the Allom farmers left Morgan engaged.
1730. Swift, Lady’s Dress. Room, Wks. 1755, IV. I. 114. Allum-flower to stop the steams.
1386. [See under 1.]
a. 1500. E. E. Misc. (1856), 78. j di, of alome glas molte into clere water.
1758. Phil. Trans., L. 688. What we call allum-rock, a kind of black slate that may be taken up in flakes.
1875. Ure, Dict. Arts, I. 111. At Whitby, the alum-rock.
1872. Nicholson, Palæont., 513. Beds of so-called ‘alum-schist,’ which are of Upper Cambrian age.
1875. Ure, Dict. Arts, I. 111. Such alum-shales as contain too little bitumen for the roasting process.
1805. Edin. Rev., VI. 237. He also classes the alum-slate … among the transition rocks.
1875. Ure, Dict. Arts, I. 111. The ustulation of alum-slate.
1833. Lyell, Princ. Geol., III. 223. A rent in the trachytic mountains of Budoshagy exhales hot sulphureous vapours, which convert the trachyte into alum-stone.
1875. Ure, Dict. Arts, I. 109. The alum-stone appears to be confined to volcanic districts.
1868. Dana, Min., 659. Alunite was first observed at Tolfa, near Rome, in the 15th c. by a Genoese, who had been engaged in the manufacture of alum, from an alum-stone or ‘Rock-alum’ found near Edessa in Syria.
1617. Bacon, in Fortescue Pap., 34. The offers made … to your Majestie of his allome workes.
1641. in 4th Rep. Hist. MSS. (1874), 42/2. William Turnor, and others, who farmed the alum works of his late Majesty.
1875. Ure, Dict. Arts, I. 119. Boiling the scum of the alum works.
