triple Sulphuret, of Lead , Antimony, and Copper, &c. 53 
of copper, and wishing to have the truth of this opinion ascer- 
tained by chemical analysis, I desired Mr. Chenevix, about 
two years ago, to be so good as to analyse seven different spe- 
cimens of the above-mentioned ore, in which I suspected the 
presence of antimony. I requested him, at the same time, to 
search with every possible care, for any metal the ore might 
contain besides copper and iron. Of these seven specimens, one 
came from Kapnick in Transylvania, one from Merkirch in 
Alsace, one from Andreasberg in the Hartz, one from Gross- 
mandorf in Saxony, one from Frey berg in Saxony, one from 
Hesse, and one from the Alps of Dauphiny. Not one of them 
contained a particle of lead, or of silver ; but every one of them 
contained antimony, although in such various proportions, as 
to exhibit the following differences; viz. J yL , 
and From these results, (whatever error may be supposed 
to have been committed in the operation,) no one, I think, can 
possibly consider antimony as really forming a constituent part 
of this sulphuret. Two of the above-mentioned specimens pos- 
sessed a determinate crystalline form, namely, a tetraedron. 
One of them, which came from Kapnick, contained A 8 . of 
antimony ; the other, which came from Hesse, contained 
In order to complete this investigation, after having given Mr. 
Chenevix some other specimens of this gray sulphuret of cop- 
per, which had no appearance of crystallization, and which he 
found to contain nothing but sulphur, copper, and iron, without 
any trace whatever of antimony, I desired him to be so good as 
to add to his analyses, that of some very brilliant crystals of this 
same sulphuret, which came from Cornwall, and which were in 
the form of a tetraedron, with the edges doubly bevelled, and 
the solid angles truncated. They also were found to contain 
