146 DESCRIPTIONS OF MINERALS. 
Composition. PbS=Sulphur 13:4, lead 86°6=100. Often 
contains some silver sulphide, and is then called argentifer- 
ows galena ; and at times zine sulphide is present. The ore 
of veins intersecting crystalline metamorphic rocks is most 
likely to be argentiferous. ‘The proportion of silver varies 
greatly. In Europe, when it contains only 7 or 8 ounces 
to the ton it is worked for the silver. The galenite of the 
Hartz affords -03 to 05 per cent. of silver; the English -02 
to -03 per cent. ; that of Leadluills, Scotland) vaio. wan 
that of Pike’s Peak, Colorado, °05 to -06; that of Arkan- 
sas, 03 to °05; that of Middletown, Ct. 15 to- 205 thintt on 
toxbury, Ct., 1 "85 ; that of Monroe, On OnOm while that of 
Missouri afforded Dr. Litton only 0012 to “0027 per -cemna™ 
A little antimony or cadmium is sometimes present. 
B.B. on charcoal, it decrepitates unless heated with cau- 
tion, and fuses, giving off eau coats the coal yellow, 
and ‘finally yields a globule of lead. 
Diff. Galenite resembles some silyer and copper ores in 
color, but its cubical cleavage, or granular structure when 
Tmgccive! will usually distinguish it. Its reactions before the 
blowpipe show it to be a lead ore, and a sulphide. 
Obs. Galena occurs in granite, limestone, argillaceous 
and sandstone rocks, and is often associated with ores of 
zinc, silyer and copper. Quartz, barite, or calcite is gener- 
ally the gangue of the ore; also at times fluor spar. The 
rich lead mines of Derbyshire and the northern districts of 
England, occur in the Subcarboniferous limestone ; and the 
same rock contains the valuable deposits of Bleiberg, in 
Austria, and the neighboring deposits of Carinthia. ‘The 
ore of Cornwail is in true veins inter secting slates and is 
argentiferous. At Freiberg in Saxony, it occupies veins in 
gneiss; in the Upper Hartz, and at Przibram in Bohemia, 
it traverses clay slate, of Lower Silurian age; at Sahla, 
Sweden, it occurs in crystalline limestone. There are other 
valuable beds of galena, in France at Poullaouen and Huel- 
goet, Brittany, and at Villefort, department of Lozcre; in 
Spain in the granite and ar gillyte hills of Linares, in Cata- 
lonia, Grenada, and elsewhere ; in Savoy; in N etherlands at 
Vedrin, not far from Namur ; in Bohemia, southwest of 
Prague ; in Joachimstahl, where the ore is worked princi- 
pally for its silver; in Siberia in the Daouria Mountains in 
limestone, ar oentiferous and worked for the silver. 
The deposits of this ore in the United States are remark- 
