LOCALITIES.--Found west of Harrisburg, Pa., in rocks (slates and sandstones) less disturbed than in the _Anthracite_ region. Western Pennsylvania; South-east Ohio; West Virginia; Eastern Kentucky and Tennessee to Tuscaloosa; North-west Kentucky; Illinois; Iowa; Missouri; Kansas; Arkansas; Northern Texas; Central Michigan; Owyhee County, Idaho; Deer Lodge and Gallatin Counties and sixty miles north-east of Bannock, Mont. 11.--BLENDE. Occurs in crystals and masses; waxy lustre, but not always very apparent; usual color, rosin-yellow to dark brown; brittle; the powder, which is whitish to reddish-brown, dissolves in muriatic acid giving off the odor of rotten eggs; by roasting gives off sulphur-fumes; infusible alone, but on charcoal at a high heat gives off white fumes; gravity 4. VALUE.--An ore of zinc (containing sixty-six per cent.) and a source of white vitriol. Often worked for its _Silver_ and _Gold_. LOCALITIES.--Found with lead and other ores. Lubec and Bingham, Me.; Eaton, Warren and Shelburne, N. H.; Sterling, Southampton and Hatfield, Mass.; Brookfield, Berlin, Roxbury and Monroe, Conn.; near Wurtzboro’, Cooper’s Falls, Mineral Point, Fowler, Ancram, Clinton and Spraker’s Basin, N. Y.; Wheatley and Perkiomen lead-mines, Schuylkill, Shannonville and Friedensville, Pa.; Austin’s lead-mine, Va.; Haysboro’, Brown’s Creek and Polk Counties, Tenn.; Prince Vein, Mich.; Dubuque, Ia.; Warsaw, Rosiclare and Galena, Ill.; Shullsburg, Wis.; Stillwater, Minn. 12.--BOG IRON ORE. Occurs in masses or beds, looking much like hard brown earth; loose or porous and earthy, rather than compact and nodular; powder yellowish-brown; when strongly heated becomes black and magnetic; gravity nearly 4. An earthy yellow variety is called _Yellow Ochre_. VALUE.--An important ore, yielding thirty-five per cent. LOCALITIES.--Found in low, marshy grounds; widely distributed. Lebanon, N. H.; Berkshire and Plymouth Counties, Mass.; Columbia, St. Lawrence, Franklin and Jefferson Counties, N. Y.; New Limerick, Katahdin, Newfield, Shapleigh, Argyle, Clinton, Williamsburg and Lebanon, Me.; Darien and Martin Counties, Ind.; Monmouth County, N. J.; Somerset and Worcester Counties, Md.; Michigan, Ohio, Illinois, Wisconsin, etc. 13.--BRITTLE SILVER ORE. Occurs in crystals and masses; metallic lustre; tarnishes yellow, gray and finally black; easily cut or broken; when heated gives off fumes of sulphur and antimony, affording a button of silver; dissolved in nitric acid, it silvers copper placed in it; gravity 6. VALUE.--A rich ore of silver, containing over sixty per cent. LOCALITIES.--Found in veins with other silver ores, in Nevada and Idaho. 14.--BROWN COAL. Occurs like _Bituminous Coal_, but usually brownish-black with less lustre, and often showing a woody or slaty structure; powder always brown; contains fossil plants; gravity between 1.2 and 1.5. VALUE.--Inferior to No. 10. Makes no coke. Can be used in the manufacture of alum.