A M A 



prti-ary refcue from th:r boflile attacks of their pnemies, 

 and thus were in foine degree rccompcnfcd for their chari- 

 table zeal on behalf of the pil~riris and fojourncrs in Palc- 

 iVuit. From tlie year i too, ■> I. n duke Rotjcr too.; pof- 

 fflFion of this ilate, and aboliih.ci even the ' ' .. ' its 

 rc'niblican conftitution, it has been cxpofod ks 



of every power at variance with its now i-nail,-, ; i ' pil- 

 lage of it by the Pifans forms an interciii";; O'loclu! i'l its 

 hilloiy; for they carried away the Pandects, a copy of 

 the CouE which was formed by Juftinian the firft : a mer- 

 chant had brought it as a curiolity from Greece, but it had 

 obtaiaed no authority at Amalii, wliere the Theodofian 

 code was in force. Amalii, after the di:llruflion of its li- 

 berty, found that its commerce declined. Trade was en- 

 tirely loll to this coall in the reign of Joan the firll. The 

 nllenation of its lord'.hip to fcud;!l proprietors was without 

 doubt a circnmftance that luiRened its d Ifolution. The 

 lii-olher of pope Martin V. (Colonna) had the lirll grant of 

 Amahi ; the Sanfcvcrini the next ; tlien the Orfiiii acquir- 

 ed poflcffion ; and laiUy, Picolomini enjoyed it with the 

 title of duke. 



Amalfi is now merely a (hadow of what it was in mag- 

 nitude, connections, and real importance, when it was in its 

 fl'juvilhirig ilate : when, from a narrow, though fertile, ex- 

 tent of land, by means of an aeceiTible and open fea, it 

 iupplied the wellern world with the manufatlures and pro- 

 ductions of the call ; when 50,000 citizens were numbered 

 within its walls : wiien it was more abundantly than any 

 other city provided with gold, filver, and the objects of 

 precious luxury; and when its fcttlements in Conftantiuople, 

 Antiorh, Jerufalem, and Alexandria, acquired the privileges 

 of independent colonies. Its buildings are not remarkable for 

 elegance and iize, and contain at moll 4000 inhabitants, who 

 fecm to be in a poor condition. It prefents few objefts 

 tliat can recall any idea of its ancient profperity. The ca- 

 thedral is not an agreeable building ; under the choir is the 

 chapel and tomb of the apolUe St. Andrew, in whole ho- 

 nour the edifice was dedicated, when cardinal Capuaiio, in 

 1208, brought his body from Conllantinople. Swinburne's 

 Travels, vol. iii. p. 220 — 236. Gibbon'sHift.vol. x. p. 280. 



AMALGARI, ylmal^ame, Fr. — ylmr.lgama or i^ikkbrey. 

 Germ. — /Imalgnma, Ital. 



The word amalgam, from a^a and •/a^m, conniibium, is a 

 ■metaphorical term invented by the ancient chemilts, and re- 

 tained by the moderns to iignify any metallic alloy, of 

 which mercury forms an effential conilituent part. Hence, 

 as mercury remains fluid at the ufual atmofpherieal tempe- 

 rature, the theorj' and general phenomena of amalgamation 

 may be laid to be thofe of the folution of metals in 

 mercury. 



All that is peculiar to the fevcral amalgams, fuch as the 

 method of preparing them, their charaCltriRic phyfical and 

 <;hemic->.l properties, and the ufes to which they are appli- 

 cable will be detailed hereafter in the article msrcury ; but 

 befides thefe there I'tmain to be dcferibed a nimiber of ge- 

 neral facts and appearances common to all amnlgams, wliich 

 may be treated of with more propriety here than clfe- 

 where. 



The knowledge of the folvent power whicli mercury 

 exercifes over various metals, c(])eeially gold, was not only 

 known by the ancients, but, as we learn from Pliny, was ac- 

 tually employed by them in the feparation of gokl from 

 the bafer metals and in the gilding of fiiver. Velnfco and 

 Alonzo Barba, in the i6th century, applied the procefs of 

 amalgamation in the great way to the extraction of filver 

 from the ores of i'eru and Mexico ; but of the early the- 



A M A 



mlfts, Borrichius, Ofiander, Beechcr, and Slahl, are th« 

 only ones wlio iiave treattd of various amaleanui with the 

 view of comparing their refemblanccs, of notnig llieir pecu- 

 liarities, and thence deducing a few general axioni-s for the 

 benefit of feiencc. Rouelle and Fufchcl, foUovxinR tlie 

 ilcps of their predeceffor*, difeovcrcJ the cryllalll?.ability 

 ot metals from tlieir folutions in mercury, and Sji;e ha« 

 fmce cr.rielied this department of chemical jihilufophy with 

 a vail number of cunou3, concc\, and important obfcr»a- 

 tions. 



f I . Melhodi of preparing Amal^ami, 



The precautions required in the preparation of an amal- 

 gam depend confiderably on tiie degne of aflinity fubfilling 

 between tlic mercury and tlic metal made ufc of. Wliire 

 the ailinity is very powerful, as in the cafe with gold and 

 fiiver, the fluidity of the mercury without any f.ir'.lier con- 

 dition will effect a combination even at t!ic ufual atmofpha. 

 rieal temperature. Thus leaf-gold, by fimpic triluratioo 

 with mercuiy will form an amalgam in a few miiiutea ; ar.d 

 pieces of gold, lilver, or tin, even of confiderable tliiekntf.*, 

 by being immerfed in pure mcrcuiT will, in a f-'w days with- 

 out trituration, be wholly diffolved. Other metal* of 

 ftronger cohefion or weaker affinity require the aniftancc of 

 heat to make them amalgamate, fueh are zinc and antimony! 

 for this purpofe the zinc is melted in a craciblc, and being 

 then \\ithdrawn from the fire is allowed to cool till it it 

 upon the point of becoming folid, at tliis initant the mer- 

 cury, previoudy heated to boiling, is (lirred in, and the mix- 

 ture is kept fluid by a gentle heat till the combination ap- 

 pears to be perfect : it is of confequcnec to the fafcty of 

 the operator, and the fuecefs of the experiment, that the 

 mercury fliould be jirevioufly heated, otherwife the differ- 

 ence of temperature between the two metals at the time 

 of mixture will be very apt to produce an explofion. The 

 atlual fufion of the zinc or antimony is, however, by no 

 means abfolutely neccffaiy : the metal in fmall pieces being 

 put into a crucible, the ]>roper quantity of mercury is then 

 to be added ; the interlaces will thus be filled up, and the 

 niafs being then expofed to a heal a little lefs than ttunt re- 

 quired for tlie volatilization of mercury, the amalgamation 

 will in a flwrt time be completely effedttd. Thofe metals, 

 however, that require a full red lieat for their fufion, will 

 volatilize with explofion any mercur)- that is attempted to 

 be mixed with them while in this ilate, fuch, for example, 

 is copper. This is, therefore, bell amalgamated in the 

 moid way ; for which puipofe take a boiling hot faturated 

 folution of fulphat of copper, pour it into a glafs or Wedge- 

 wood ware mortar, and add mercury and iron filings ; the 

 iron will decompofc the fulphat of copper, and precipit.t»e 

 this latter metal in a finely divided (late, which by the heat 

 and moderate trituration will unite with the mercur)-, and 

 the combination may afterwards be perfe£ted by fufion at a 

 crentle heat in a crucible. Amalgams may be made either 

 folid or fluid, according to the proportion of mercury that 

 enters into their compofition ; the quantity of this laft, 

 however, that is required to give the amalgam a fluid (late, 

 is different for each metal, for the more powerful the aflinity 

 the lefs is tiie quantity of mercury required. 



ij 2. Phcnonuiin ohfcrvnbh during Amalgamaiion. 

 All the appearances that happen during the combination 

 of metals with mercury indicate a real folution of one in the 

 otiier, owing to the chemical attraftion between the bodici 

 fo uniting. In proportion to the rcadinefs with which any 

 metal lends 10 amii.lgamalion is the force with which it ad- 

 5 L 2 here* 



