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484 AESEETATES, PHOSPHATES. o, rough, frequently concave. Cleavage, x, imperfect and interrupted ; a, hardly perceptible. Fracture imperfect con- choidal. Semi-transparent...translucent on the edges. Lustre resinous, in the brown varieties inclining to adamantine. Green, brown, yellow, grey of various shades. Streak white, sometimes inclining to yellow. Brittle, h = 3-6...40. fl = 6-9...7-1. Melts readily before the blowpipe on charcoal, and the bead crystallizes in cooling. With boracic acid and iron wire yields phosphide of iron and metallic lead. With soda on charcoal the lead is reduced. Soluble in nitric acid. The solution yields a precipitate with nitrate of silver. PbCl + 3Pb 3 P, phosphoric acid 15-77, oxide of lead 73'99, chlorine 2-62, lead 7'62. Part of the phosphoric acid is some times replaced by arsenic acid. Small quantities of lead and chlorine are also replaced by calcium and fluorine. Analyses of pyromorphite a from Mies, b from Bleistadt, o from England, d, e from Poullaouen, all by Kersten, f from Bleiberg by Bergemann:— Phosph. ox. lead . Phosph. lime . . Chlor. lead . . Pluor. calc. . . Analyses of pyromorphite g, h from Bleistadt by Lerch, i, k from Zschopau, I from Leadhills, all by Wohler, m from Kraus- berg by Sandberger:— g h i him 87'38 88'42 80‘37 89'94 88'18 89'43 a b c d e / 89-27 89-17 89-11 89-91 89-93 92'65 0-85 0-77 0-68 — — — 9-66 9-92 10-07 10-09 10-07 7*45 0-22 0'14 0-13 — — — Phosph. ox. lead Ars. ox. lead Phosph. lime Phosph. Fe . Chlor. lead . Pluor. calc. — — 9‘0l — — — 0-80 1'58 — — — — 0'77 0-60 — — — — 10-23 9'67 10'09 10-05 9’91 10'24 0-07 0-20 — — — Pyromorphite from Clausthal and from Hofsgrund in the Breisgau contains a small quantity of silver. Pyromorphite from Beresowsk contains chrome. In attached crystals ; massive ; reniform ; pseudomorphous after galeua and cerussite. Occurs in veins containing galena, to the decomposition of which it is supposed to owe its origin- Is found at Przibram, Mies and Bleistadt in Bohemia,