GALLERY.] natural history. (Minerals.) 81 
fibrous structure and yellow colour, found in the fissures of argillaceous 
iron-stone, near Zbirow in Bohemia and the cliildrenite from Tavi- 
stock, m Devonshire : both which mineral substances contain alumina 
and oxide of iron combined with phosphoric acid, but require to be sub- 
jected to closer chemical examination.— Phosphate of magnesia: the 
very scarce wagnerite , from the valley of Holgraben, near Werfen, in 
Salzburg — The mengite and edwardsite are placed in the Table Case, they 
being by some considered as phosphates of lanthan and cerium oxides 
m two of the supplemental Table Cases (57 A and B) in this room 
are deposited such phosphates as are combined with chlorides; as like- 
wise the rare combinations of the latter with carbonates and silicates. 
Case 57 A. Pyromorphite, a combination of phosphate of lead and 
chloride of lead, generally divided into brown lead ore and green lead 
ore: among the varieties of the former, the more remarkable are the 
large six-sided prisms from Huelgoet in Brittany; of the latter we 
have the massive botryoidal {traubenertz), the spicular, and crystallized 
varieties, of various shades of green passing into greenish-white, into 
yellow and orange. To these are ^ddedphosph-ar seniates and also some 
arseniatesoflead, from Siberia, Cumberland, Saxony, &c., whose che- 
mical constitution is not yet perfectly understood ; in 
. Case 57 Phosphate of lime combined with chloride of calcium , 
m some varieties of which this latter constituent is replaced by fluoride of 
calcium : among the specimens may be particularized several very scarce 
and interesting crystallizations of Werner’s apatite, such as the large vio- 
let-coloured crystals from St. Petersburg ; the groups from Ehrenfrie- 
dersdorf, Maggia on St. Gothard, Traversella in Piedmont, &c. ; the 
variety called asparagus-stone, fro m the Greiner in Tyrol, and particularly 
the specimens from Jumillain Murcia; the Norwegian apatite called mo- 
remte; also the phosphorite or fibrous and compact phosphate of lime, 
and the pulverulent variety, known by the name of earth of Marmorosh, 
which was formerly considered as a variety of fluoride of calcium (fluate 
of lime). — The only carbonate found combined with a chloride is the 
horn-lead, or chloro-carbonate of lead: the unique suite of crystals 
deposited in this Table Case is from Cromford Level, near Matlock. 
To the silicates with chlorides are referred the sodalite, of which, how- 
ever, some varieties stand in need of more accurate chemical examina- 
tion;— the eudialyte, which occurs in West Greenland, accompanied by 
the preceding mineral substances; — the pyrosmalite, from the iron mines 
of Nordmark, in Wermeland, massive and in perfect crystals. 
Case 58 contains \he fluorides, of which by far the most important 
species is the fluoride of calcium, generally called fluate of lime and 
fluor-spar : among its numerous varieties may be particularized, the 
rose-coloured crystals from Chamouni ; the phosphorescent massive 
fluor-spar, called chlorophane, from Siberia ; the varieties called forti- 
fication- fluor ; earthy and compact fluor, &c., chiefly from Derbyshire 
and Saxony — The very scarce fluoride of aluminum, from Cornwall, 
called fluellite. — Fluoride of calcium, yttrium, and cerium; — yttrocerite • 
and some related minerals from Finboand Brodbonear Fahiunin Swe- 
den — Fluoride of sodium and aluminum, called cryolite, found in West 
Greenland: pure and mixed with brown iron-stone, galena, &c. : the 
chiolite, from the Ural. 
Case 58 A, is appropriated to some of the silicates containing fluo- 
e 3 
