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ALUM.

individual who knew how to render glass malleable, Tiberius ordered to be put to death. Plin. xxxvi. 3G. Petron. Arhit.51. Isidor. xiv. 15. Dio. lvii. 21.

ALUM.

Term defined. — Called by the Latins alumen; by theGreeks it was termed atuir-rnpice, from its styptic or astrin-gent qualities. It is an astringent neutral salt, usuallyfound in calx of one of three minerals, iron, copper, or zinc;or it is found in an earth of a peculiar white colour, andfrom its commixture with this vitriolic salt, called alum-earth. The preceding description of alum refers only tothat obtained by cliymical process. The ancients, it is pre-sumed, knew not of the manufacture of alum, because someislands in the Grecian and Tuscan seas produced naturalalum, called also rock alum, in great abundance; in theislands of Melos, Lipara and Strongyle, now called Milo,Lipari, and Slromboli. We understand it was also anarticle of Egyptian produce, for in the period of Amasis,King of Egypt, the temple of the Delphian Apollo havingbeen destroyed by fire, the people of Delphi procured sub-scriptions from various princes for the purpose of reinstatingit; among others who subscribed liberally to repair this loss,the above-named Egyptian prince sent them one thousandtalents of alum.

It is of a nature so nearly allied to vitriol, that the calxcontaining it is generally found in the vicinity of vitriolworks. Also alum with vitriol contains the vitriolic acid.The earliest mention discovered in the ancients of alum, orvitriol, (by which name, it is surmized by a recent writer,we should understand the substance w r e now call alum,) isfound in the works of that eminent naturalist Pliny , wherehe says, blue vitriol w r as made in Spain by the process ofboiling. Scopoli and Sage, we understand, deny the ex-istence of alum in our day in a natural state. Notwith-standing Linncens and Morand, in their journey throughScandinavia , discovered some crystals of this kind, de-scribed in pages 291 and 469 of that work. It is, however,alleged by the before-mentioned waiter, that real alum *crystals are formed very rarely on minerals which aboundin a great degree with aluminous particles, and not till theyhave been exposed a suilicient time to the open air and tothe rain; and even then, he observes, they are so small, and