302 Analyjis of the Arfeniates 



I have now mentioned the mod material circumftances 

 which huve occurred to me concerning our late refpefted 

 fneml. There are feveral of them which I have related 

 ra'ihcr becaufe they were fafts, (and every faft relative to a de- 

 parted friend feems interefting to his furvivors,) than becaufe 

 1 thought them of fufficient importance to be laid before the 

 public. I am, dear Sir, 



With great efteem. 



Yours very fincerely, 



Thomas Arnold. 



LIT. Analyjts of the Arfeniates of Copper and of Iron. By 

 Richard Chenevix, Efq. F.R.S. M.R.I.A. 



[Concluded fioai p. 229.] 



Section III. 



Analyjts of the Red Oflaedral Copper Ore, in luhich the 

 Metal ex'ijls in a State hitherto unknown in Nature. 



J.N the coiirfe of the experiments which have been ftated in 

 the preceding feftions, I have had occafion to examine a great 

 number of copper ores, and particularly of copper ores from 

 Cornwall ; but the only one which has afforded any intereft- 

 ing refults, is the well known fpecies called red copper ore, 

 cryftallized in regular and brilliant o&aedrons. It has been 

 fo long known, and fo often mentioned by mineralogifts, that 

 it may excite our wonder when wc refleft, that its chemical 

 nature has never been afcertained. For it would be an in- 

 juftice to that very accurate and fcrupulons analyft M. Vau- 

 quclin, to fuppofe that he meant to pronounce decidedly upon 

 that point by the fingle experiment which he had made *, 

 and which is mentioned by the abbe Hauy in a (hort extract 

 of his cryftallographical arrangement of mineral fubllances, 

 publifhed in the Journal des Mines. 



Rome de Lifle, the baron de Born, Lametherie, the abbe 

 Hauy, and indeed every other mineralogift, concur in calling 

 this fubftance red calx of copper; but fome of them afiert 

 that it contain? a portion of carbonic acid. Among the 

 many analyfcs which have been made of this ore by Fon- 

 tana, Monnet, De Born, Renovantz, and others, I could 

 not find one, that in the proportions, or even in the ingre- 

 dients, refembled what I had found to be its contents. The 



* He mcrtlv poured muriatic acid upon the ore; and, as it was entirely 

 dKTolved, without cfF.rvefccncc, concluded it to be an oxide, and not a car- 

 bonate, of copper. 



higheft 



