On the Formation of Ores. 353 
were visible. Under the green crust or aerugo, was a layer of 
well marked crystals of red copper. The Roman vessel, found 
near Bonn, appears to have been exposed to considerable heat ; 
therefore, the red copper, in that case, may have been the re- 
sult of fusion, but no traces of fire could be detected in the copper 
relics of Triers, nor in that of some other specimens we shall now 
mention. Sage observed crystals of red copper on an old copper 
statue, found in the Soane in the year 1766. Demeste mentions 
crystals of red copper he saw in the hollows of the fragment of the 
leg of a bronze horse, which had lain for some hundred years un- 
der ground. Morveau says, the crystals were of two kinds, one 
ruby red, being red copper ; the others emerald green, and these 
were malachite ; and Demeste adds, that some of the hollows 
also contained crystals of blue malachite or blue copper. Vau- 
quelin informs, that, on examining the fragment of a statue, which 
had been long buried, he found the exterior of red copper, and 
the interior of copper in its metallic state. It is evident, that these 
changes in the copper, in the specimens just enumerated, had 
been produced by the action of the atmosphere and of percolating 
water. It is equally well known, that similar changes have 
been produced on copper, when fused under particular circum- 
stances. Examples of this kind were met with in masses of 
copper inclosed in the lava, which, in the year 1794, flowed 
over a considerable space of the district of Torre del Greco. 
Common copper coins were converted into red copper, and, in 
some specimens, the surface was crystallized, while the interior 
had a radiated structure. In some of the specimens of brass 
candlesticks from Torre del Greco, preserved in the Museum 
of the University of Edinburgh, the zinc has separated from 
the copper. On some of them there are small brownish crystals 
of translucent blende, numerous octahedrons of red copper, and 
very beautiful copper- red cubes of pure copper. In other spe- 
cimens; from Vesuvius, mentioned by authors, the zinc and cop- 
per have separated, and each appears crystallized in their due 
forms. Masses of iron, partly crystallized in octahedrons, and 
also in the state of iron-glance and sparry iron, have been found 
in the lava of Vesuvius. Silver in beautiful octahedrons, lead 
in the state of litharge, and galena, or lead -glance* in the 
cubo-oetahedral form, have also been collected from the lava @fi 
Torre del Greco.— Vid, ScJiweigger's Journal. 
