eaS Mr. Chenevix’s Analysis of 
results, is the well known species called red copper ore, crys- 
tallized in regular and brilliant octaedrons. It has been so long 
known, and so often mentioned by mineralogists, that it may 
excite our wonder when we reflect, that its chymical nature has 
never been ascertained. For it would be an injustice to that 
very accurate and scrupulous analyst, M. Vauquelin, to sup- 
pose, that he meant to pronounce decidedly upon that point, by 
the single experiment which he had made, * and which is men- 
tioned by the Abb6 Hauy, in a short extract of his crystallo- 
graphical arrangement of mineral substances, published in the 
Journal des Mines. 
Rome' de Lisle, the Baron de Born, Lametherie, the Abbe 
Hauy, and indeed every other mineralogist, concur in calling 
this substance red calx of copper ; but some of them assert, 
that it contains a portion of carbonic acid. Among the many 
analyses which have been made of this ore, by Fontana, 
Monnet, de Born, Renovantz, and others, I could not find 
one, that in the proportions, or even in the ingredients, resem- 
bled what I had found to be its contents. The highest amount 
of copper, (that given by Fontana,) does not exceed 66 per 
cent, and is far short of the real quantity. The remainder, as 
he states, consists of water, and of pure and fixed airs. The 
difference in the results I had obtained, together with some new 
facts, which I had occasion to observe during my experiments, 
induces me to treat the subject at some length ; referring for its 
external characters, to those mineralogists above mentioned, 
who have amply described the ore, and confining myself entirely 
to its chymical analysis, and some analogous experiments. 
• He merely poured muriatic acid upon the ore ; and, as it was entirely dissolved, 
without effervescence, concluded it to be an oxide, and not a carbonate, of copper. 
