Page:Cyclopaedia, Chambers - Supplement, Volume 1.djvu/125

 ALU

ALU

Round Alum, Alumen rotundum, called alfo noyyv'kn, as being found ordinarily in roundifh manes, though fometimes an- gular.

Some diftinguifh the Alumen rotundum into divers kinds, viz. . Bullofu?n, of a whitifh colour, without fand, and very friable; . Pumicofum, porous, or full of holes like a fpunge ; Ar%u.yxKv\m, or talare, in form of a dye ; n?>»Gi7nf, or latercularium, flat, refembling a trencher ; n?>axilK, or crujlarium, formed of divers crufts or coats. Vid. Plin. Hift. Nat. T. 2. 1. 35. p. 716. Gal. deComp. Med. fecund, loc. 1. 6. Diofcor-. 1. 5. c. §2. Mercat: Metalloth. Arm. 3. c. 1. p. 53. Kirch. 44und. Subterr. 1. 6. fee. 3. c. 1. p. 312. Scifflle, or foffile Alum, is either compofed of thin flakes, very friable to the fingers, or of Stria?, or whitifh hairs, hence called t^i^iIk, or capillary Alum, ufually plume Alum. But it may be obferved; few, if any* of the antient native Alums, are known among the moderns ; though fpecimens of this or that kind are fhewn in the collections of the curious. Pomet, Hift. des Drogues, P. 3. 1. 2. p. 80. The modern Alums are chiefly artificial, and may be reduced to two kinds ; rock, or roche, and common Alum. The coun- tries wherein they are chiefly produced are England, Italy, lome parts of Germany, and Flanders. Roche, or rock Alum, is a whitifh tranfparent fait, of an auftcre aftringent tafte, rarely found in veins per fe, but extracted by burning and lotion from aluminous ftones, or by boiling from mineral waters, exhibiting cryftals, ufually of the figure of . o&ohedrons, or double pyramids, with fquare bafes, joined together at their bafes. Vertlr. Phyf P. Spec. c. 6. p. 464. Lift, de Therm. Guliclm. de Salib. ap. Allah. Not. ad Mer- cat. lib. cit. c. 2. p. 56.

■ Rock Alum is fo called, becaufe prepared of the fragments of certain rocks, or ftones calcined. Scalig, Exere. ad Card. 104. §. 6.

Alume di rocca, among us frequently common Alum, as being that chiefly now in ufe.
 * This is otherwife called Alumen rupeum, and Alumen rocha;

Rock Alum is, by fome, pretended to be the fame with the liquid Alum of the antients. In proof hereof, Brafavolus al- .. ledges, that the rock Alum procured in the pope's territories, is originally liquid. But later and better enquirers fhew this to be wholly a miftake. Mercat^ ubi fupra, c. 2. p. 54, Kirch, loc. cit.

Dale, and fome others, will have rock Alum, properly fo called, confined to the red Alum^ prepared from a reddifh ftone, ufually called Roman Alum, But, in the popular ufe, rock Alum is extended to all the Alums made from ftones, by way of contradiftinction from common Alums, which are pre- pared from earths.

Sacbarine Alum. See Allum, Cycl.

This is alfo called Alumen Zuccarium. Kirch. Muhd. Subter. loc. cit. Vater, Phyf. Exper. fee. 5. c. 4. p. 417.

■Burnt Alum, Alumen uftum, is prepared by melting the fait in a fire-fhovel, or crucible, and letting it bubble till it comes to a white hard fubftance. This is ufed as an efcharotic ; it gently eats proud flefh, but leaves fuch a hardnefs on the part, as makes it little efteemed in that intention. Many mix a little of it with the fugar they dulcify their cordial waters with ; which fines them down, and throws the milkinefs to the bottom, from which they may be poured

. by inclination, or rack'd off with a crane, ^uinc, Difpenf. p. 274.

Diofcorides enumerates abundance of virtues and ufes of the Alumen uftum a. Of this is prepared Tenzelius's aqua ar- canee contra ifcbiatn cif contra ariduram b. — [ a Diofcor. 1. 5. c. 123. b Burggr. Lex. Med. T. 1. p. 490. feq. See further concerning the ufe of burnt Alum, as a feptic, &c. in Junck. Confp. Chirurg. p. 333. Ejufd. Confp. Medic. p. 470.]

Plume Alum, Alumen plumofum, is found chiefly in the ifland of Rhodes and Crete, where there are whole mountains of it. The plume Alum is fcarce known in thefe countries ; what we have under the name in England, &c. being only a coarfe fort of amianthus, from which the true plume Alum differs in many refpects. The latter has a real faline aluminous tafte, 1 and, like other forts of Alum, a ftrong aftringent quality ; whereas the former does not belong to the clafs of felts, but of ftones, and is neither aftringent nor fapid, except that it is a little pungent to the tafte ; nor does it diflblve in water, as the plume Alum ought to do : add, that it bears the fire, grow- ing red hot in it, without fuffering damage, which the Alum will not. Junck. Confp. Terap. tab. 16. p, 453. Id. Confp. Chem. p. 269. feq. Hift. Acad. Scienc. an. 1706. p. 412. See Asbestos.

Alumen plumofum is alfo a name given, by fome chemifts, to a peculiar kind of fublimate of mercury, invented by Bafil ■Valentine, whofe name it alfo bears.

The preparation of the Alumen plumofum Bafilii Valentini is thus : take of mercury one part, diffolve it in fix times the quantity of- aqua 7 fortis, or aqua-regia ; concentrate the Solu- tion, in a retort, to a drynefs, and while hot, add to it one half, or one part, of rectified oil of vitriol ; drive it a new over a gentle fire, till it rife flaky, and fill the neck of the retort. '

Suppl. Vol. L

This is the plume Alum, which may be eafily converted into aqua mercurialis. Vid. Teichmey. Inft. Chem. P. 2. c. 10. P- 147-

Alumen fcagliola, or fcalola, a fquamofe or flaky ftone, the fame with what is otherwife called lapis fpecularis. Mercat. ubi fupra, c. 2. p. 56. Sec Specularis. Some take this for the fame with what the antients called fchifton. Kirch, loc. cit.

Alumen catini, is a name which fome have given to the afhes, or rather fait of the herb kali, ufed chiefly in the making of glafs. Mercat. & Kirch, ubi fupra. See Kali. In this fenfc, Alumen catini amounts to the fame with what is more frequently called alkali. See ALKALI.

ALUMEN_/im'x is made of the lees of wine, formed into round manes, dried by the fun; and then burnt or torrified fo long by the fire, as to turn white. Its chief ufe is among the women, to dye their hair of a yellow colour, much affected in Italy. Mercat. loc. cit.

Purified Alum is that prepared by diflolving it in hot rain water, and evaporating it again, till it fhoot into cryftals. By repeating this operation diverfe times, the fourhefs of the Alum is much abated.

Crude Alum is the fait, fuch as produced at the Ah/?n-works$ without further preparation. This ftands contradiftinguifhed from prepared Alum.

It is, by fome, ufed as a noflrum againft the itch and fwellings of the feet ; but rather palliates than works a thorough cure. Junck. Confp. Therap. tab. 16. p. 453.

Prepared Alum is of divers kinds. — Under this clafs come- pu- rified Alum, facharine Alum, burnt Alum, Alum magifleries", tinctures of Alum b, water, fpirit, dulcedo of Alum c .' — [ a V,; Tenzel. Exeq, Chem. ap. A. Salam, Opp. p. 665. b Burggr. Lex. Med; Ti 1. p. 486. feq. c Poter, Pharmac. 1. 2. c. 9.]

Roman Alum properly denotes' a rock Alum, of a fed colour, prepared in the country near Rome.

In the genuine Roman Alum, the red colour is not fuperficial.; but diffufed through the whole fubftance of it ; by' which it may be diftinguifhed from the fpurious, or counterfeit kind, which is only the common Englifh Alum dyed red. Pomet, Hift. des Drog. P. 3. 1. 2. c. 46. p. 87. Alum is of uCc in medicine, — 'Many have been cured of agues with a nutmeg and its weight of Alum, powdered, and divided into three dufes, every morning fafting. Quincy has found its chief fuccefs this way, to have been in ftrong tough confti- tutions. The rationale of this coincides, in fome mcafurej with that of the operation of the bark. $htinc. Difp. P. 2. §• 151- P- 98.

And Alum poffet is received into the London Difpcnfatory. The bafis of Helvetius's ftyptic powder is Alum 3 the pro- priety of adding the dragon's blood is queftioned in the na- rative prefixed to the laft edition of thatPharmacopcea. The Alufn brought from the ifland of Melos was antiently ufed by the women, to prevent conception : to this purpofe^ before copulation, they applied it on the os vulvx, that by its aftringent virtue, the mouth of the utcrua might be clofed, fo as to hinder the ingrefs of the femen \ Alum is alfo find to be a capital ingredient in nil thpfc medicaments ufed by women of later times, to conftringe the pudendum, and make the lofs of virginity lefs perceivable b. A late writer pretends, that the German matrons, of beft character, practice the fame after child-bearing, to render themfclves more agreeable to their hufbands c. — [» Diofcor. 1. 5. c. 123. b V. Bartbok A&. Med. T, 4. obf. 41. p, 133, c Burggr. Lex. Med. T. 1. p. 488.]

Some antients fpeak of another ufe made of Alum, viz, to render wood incombuftiblc, by fmearing it with a folution of this fait. Archclaus king of Cappadocia is faid to have made ufe of this expedient, to render his wooden tower, which de- fended the Piraeus fecure from fire. What the Alum mufl have been, that was endued with fuch virtue, it is hard to fay; for 'tis certain ours is not. See A. Gelt. 1. 15; c. 1. Bayle, Diet. Crit. T. 1. p. 295. feq. in voc. Archclaus, Not. (P.) Bibl. Raif. T. 5i p. 131. Mel. Sylv. c. 31. §. 7. p. 199.

Alum is ufually faid to contain but very little or no fpirit ; a pound of it fcarce affords a few drops d. The reafon is, Alum is of a very fixed nature, becaufe its calcarious earth is inti- mately united with the acid fait ; and cloggs it in fo great quantity, that they are hardly feparable by the impulfive mo- tion of the fire. A vehement heat, inftead of making a fe- paration, deftroys the faline part, by evaporating its water ; and thus the fine proper earthy part conies to be detained in the groffer and lefs proper. Hence 'tis in vain to expect a fpirit from common Alum f i. e. a feparation of its faline part, 1 without the aififtance of crystallization, by means of the finer waters, or elfe the interpofition of foine grofkr tcrreftrial body, capable of dividing and discontinuing the concrete powerfully e .— [ d Junck. ubi fupra, p. 90. c Stahl, lib. cit. p. 87.]

The phlegm of Alum remaining after distillation is held a good aftringent, on which account, fome furgeons dip all their dreffings and bandages in it, or in Alum-watbr, and, after drying, apply them to the parts for flopping the hemor- rhages of wounds. Burggr. Lex. Med. T. I. p. 490.

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