Analysis of Ores from North Carolina. 349 
consist of carbonate of lead, as far as it concerns the valuable 
portion of the formation. Bocides this we have also zinc, cop- 
per, silver, iron, manganese, silica, alumina, and magnesia ; the 
two former, and sometimes the lead, being in the state of sulphu- 
rets as well as carbonates, the silver being metallic, rarely sul- 
phuretted, and the iron and manganese as oxides, mens a 
with silica, alumina, and magnesia, the gangue. 
‘The object being to ascertain the relative amounts of the n me- 
tals and the constituents of the gangue, the analysis was con- 
ducted by simple solution in nitric acid, of all soluble materials, 
and then by igniting the insoluble with carbonate of soda and 
treating it-as a silicate. As we did not endeavor to ascertain the 
exact manner of combination in each specimen, the sum of the 
substances will necessarily vary from one hundred, which, how- 
a sa no influence. on the general 1 results. 
1, analyzed by-E. M Mayer, a. selected specimen from the 
aa ie vein, ¢ ning masses of solid silver dissem- 
inated through i ‘it, independently of small spangles barely — 
to the eye, and that Snteined in the earbonnts oP Seam’ 
Metallic silver, a. hy i 
Carbonate of lead,» . 
Sulphuret of zine, 
: 4 Peroxide of iron, 
“manganese. 
Sitiea, Pee 
gir hi os ee 
\ Magnesia, : 2 va . 
a0nie 2. i 
No. 2. ByS. M3 Zz. Blaney. Bluish grey, very taleose, contain- 
ing a few masses of silver ; the greater part of the metal being 
in the form of minute spangles, | particularly in the dark bluish 
portions of the ore, and becoming visible only when —— 
a hard and smoothisubstance on & white-surlieoy Ete 
Silve i ahh. 
Jead, ‘ ‘ trace 
Carbonate of oe 388 ne 
; ‘Oxide of a cig astute 7.50.) 5.20 
: 30.40- 20.89 
