80 natural history. (Minerals.) [north 
arseniates of lead, from Siberia, Cumberland, Saxony, &c., whose che- 
mical constitution is not yet perfectly understood ; in 
Case 57 B. Phosphate of lime combined with chloride of calcium , 
in 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, from the Greiner in Tyrol, and particularly 
the specimens from Jumilla in Murcia; the Norwegian apatite called mo- 
roxite; 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-carhonate 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 endialyte, 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 the 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 Finbo and Brodbo near Fahlun in Swe- 
den -Fluoride of sodium and aluminum, called cryolite, found in West 
Greenland : pure and mixed with brown iron-stone, galena, &c. 
Case 58 A is appropriated to some of the silicates containing fluo- 
rides : — to these belongs the topaz, here illustrated by a considerable 
series of crystals of Saxon, Brazilian, and Siberian varieties, among which 
there are several new modifications ; Saxon varieties imbedded in the 
topaz rock, an aggregate of topaz, shorl, quartz, and sometimes mica ; 
Brazilian topazes, yellow and pink, imbedded in rock crystal, &c. 
— Also the pyrophysalite from Fahlun in Sweden, and the pycnite , 
formerly considered as a variety of beryl, are referable to topaz ; — 
the chondrodite (maclurite, brucite)from New Jersey, and from Pargas 
in Finland ; and some varieties of mica and lepidolite, ( Case 32,) likewise 
contain fluoric acid. 
Case 59 contains the chlorides. — Chloride of sodium (muriate of soda\ 
or rock salt : the most interesting specimens here deposited of this im- 
portant mineral substance are, the crystallized varieties ; the massive and 
fibrous coloured varieties, the red, chiefly from Hallein in Tyrol, the 
blue and violet from Ischel in Upper Austria ; the stalactical rock salt from 
Mexico, &c. — Chloride of ammonium or sal-ammoniac , from Vesuvius, 
Saint Etienne en Forez, &c. — Chlorides of lead : to these belong, the 
cotunnite from Vesuvius; the basic muriate of lead from Mendip ; and 
the murio-carhonate of lead from Derbyshire, of which most rare sub- 
