Formation of Ores by the Action of the Atmosphere. 395 



Paris basin), he at once pronounced it to be a molar tooth of 

 the lower jaw of the Anoplothcrium commune. 



As the evidence of this tooth's having been found in the 

 quarries of fresh- water Hmestone at Binstead (I beheve the 

 lower fresh-water) rests on such accurate authority as that of 

 Mr. Allan, we may consider this important and almost only 

 deficient link in the chain of evidence that unites the English 

 fresh-water formations with those of France to be now sup- 

 plied, and hope that this discovery will stimulate others whose 

 local position affords them opportunity, to persevere in the 

 attempt to collect further traces of the remains of this remark- 

 able class of extinct quadrupeds in the fresh-water strata of the 

 Isle of Wight. — Annals ff Philosophy. 



FORMATION OF ORES BY THE ACTION OF THE ATMOSPHERE 

 AND OF VOLCANIC HEAT. 



In a late Number of the Phil. Mag. we mentioned the for- 

 mation of brown hsematite by the action of water on cast-iron 

 pipes. We have now to enumerate, from the same source, some 

 other facts of a like description. 



Nciggerath, in the third volume of his work entitled Das 

 Gebirge in Rheijiland, Westphalen, notices the formation of 

 crystals of red copper-ore on a fragment of a Roman copper 

 vessel which was dug up near to the city of Bonn. The inner 

 and outer surface of the vessel was covered next to the copper 

 v.ith a delicate layer of red copper in small but beautiful do- 

 decahedral and cubo-octahedral crystals; and immediately over 

 this was an extremely thin layer of film of a green colour, and 

 which might be considered as malachite. Noggerath also ob- 

 served, in a collection of antiquities at Triers, some wrought 

 pieces of copper, several inches long and pretty thick, which 

 were found amongst Roman ruins, and appeared to have served 

 as architectural ornaments. They were so corroded on the 

 surface, that little of their original form could be observed. 

 In some places traces of gilding were visible. Under the green 

 crust or aerugo was a layer of well-marked crystals of red cop- 

 per. 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 result 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 

 hi the Soane in the year 1 766. 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 son)e hundred years un- 

 derground. Morveau says, the crystals were of two kinds; one 



.S I) 2 ruby- 



