▪ I. alum, n.
(ˈæləm)
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 fire-proof; 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 alum 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 Mandeville ix. 99 About that see growethe moche Alom. c 1386 Chaucer Can. Yeom. Prol. 260 Tartre, alym, glas [v.r. alum, alumglas(se, alem]. 1436 Pol. Poems II. 172 Coton, roche-alum, and gode golde of Jene. 1453 in Heath Grocers' Comp. (1869) 422 Alum, foyle or rooch, y⊇ 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 M. 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{p}{pp}M(SO4)2 + 12 H2O; all of which crystallize in octahedrons: distinguished as common alum 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 alum 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 B. 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. n., as alum-bearing, alum-maker, alum-making, alum-manufacture; in instrumental relation to pa. pple., as alum-steeped; in simple attrib. relation, as alum-crystal, alum-house, alum-liquor, alum-water; or attrib. relation of material, as alum-styptic.
| 1578 Lyte Dodoens vi. xxx. 697 Soked, or delayed in allom water. 1587 Harrison Engl. i. ii. xxiii. 348 A tast much like to allume liquor. 1656 W. Dugard Lat. Unlocked §443 Hee wetteth with allom-water every sheet of thinner paper. 1674 Ray Coll. Words 139 The Liquor..is conveyed to the Allom-house. 1711 Pope Rape Lock ii. 131 Alom-stypticks with contracting pow'r Shrink his thin essence like a rivelled flow'r. 1830 G. Colman Random Rec. I. vi. 187 Most readers will pardon me for not taking them into the Alum-House, to explain the several methods of crystallization &c. 1837 Syd. Smith Let. Wks. 1859 II. 277/1 Let him drive his alum-steeped loaves a little further. 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. 1875 Ure Dict. Arts I. 117 Alum Liquors,—In the alum works on the Yorkshire coast, eight different liquors are met with. |
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-mine, raw material from which alum is obtained; 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.
| 1611 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. 1612 W. Strachey Travaile into Virginia (1849) i. i. 33 We doe already heare the Indians talke both of allam mines and copper. 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 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. |
▪ II. alum, n.2 Now U.S. colloq.
Brit. /ˈaləm/, U.S. /ˈæləm/
Forms: 16 19– alumn, 19– alum, 19– alumn'
[Originally > n.; in later use independently shortened <alumnus n. and alumna n., apparently first as a graphic abbreviation.]
An alumnus; an alumna. Also in extended use.
Now chiefly as a non-gender-specific alternative to alumnus n. or alumna n.
| 1683J. Eliot Let. in Boyle's Wks. i. ccix, Your hungry alumns do still cry unto your honour for the milk of the word. 1910 B. B. Gilchrist Life M. Lyon vii. 325 The founding in 1839 of the Memorandum Society, forerunner of the later alumn' association, with the double aim of recording information about its members and preserving the records of Mount Holyoke. 1930 Amer. Speech 5 251 Alum, alumni. 1974 State (Columbia, S. Carolina) 15 Feb. 1-B/1 In more explicit—or graphic—language, streaking is darting out (unexpectedly) in the nude and from behind a tree or bush and, preferably, in front of a carload of staid old alums or grads. 1989 Spin Oct. 105/1 The recent release from Yes alums Anderson, Bruford, Wakeman, Howe isn't as bad as everyone assumes. 2000 N.Y. Press 5 Apr. ii. 2/2 As a fellow Lawrenceville alum (Hamilton Hall and Dawes Hall), I am biased in your favor. |
▪ III. alum, v.
(ˈæləm)
[f. prec. n.]
To treat or impregnate with alum.
| ? a 1500 in Middle Eng. Dict. 1598 Florio Worlde of Wordes 14/3 Allumare..to allume silkes..before they can be died into any light colour. 1735 J. Barrow Dict. Polygraphicum II. s.v. silk, How to alum the boiled silk. 1791 Hamilton Berthollet's Dyeing I. i. i. i. 19 Having alumed as completely as possible a pound of wool. 1877 W. Grey in Mackail W. Morris (1899) I. 356 Silks were alumed for to-morrow's dyeing. 1889 Internat. Ann. Anthony's Photogr. Bull. II. 108 The plate should be alumed before and after the operation. |