NATURAL HISTORY. 
[NORTH 
66 
the finest sky-blue specimens here deposited, together with the stalactic, 
fibrous and crystallized varieties, (the large group of crystals is artificially 
prepared,) are from Herrengrund in Hungary. There are also two or 
three sub-sulphates of copper placed in this Case, which, however, stand 
in need of more accurate chemical examination. — Sulphate of oxide of 
uranium or johannite, from Joachimsthal, Bohemia. — Sulphate of lead , 
lead-vitriol , or anglesite , of which we have a suite of specimens with 
brilliant and well defined crystals from Badenweiler in Suabia, from 
the Parys mine in Anglesea, &c. ; the sulphato-carbonate ( lanarkite), 
and sulphato-tricarbonate ( suzannite ), the cupreous sulphato-carbonaie 
( caledonite ) of lead, &c., from Leadhills, &c. The rest of this Case is 
occupied by sulphates of alumina :—common alum, crystallized, fibrous, 
&c., from various places; and the hydrous sub-sulphate of alumina , 
called aluminite, or websterite , from Sussex and from Halle in the terri- 
toryof Magdeburg, which was by some mistaken for pure alumina, and by 
others for hydrate of alumina with mechanically admixed sulphate of 
lime : it must not be confounded with another substance, also called 
aluminite or alum-stone , (alunite of some mineralogists,) from Tolfa, &c., 
which is a basic sulphate of alumina and potassa. 
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- fiuor; earthy and compact fluor, &c., chiefly from Derbyshire 
and Saxony.— 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, Gelena, &c. 
Case 58 a. is appropriated to the silicates, containing fluorides: — 
to these belongs the topaz , here illustrated by a considerable series 
of crystals of Saxon, Brazilian, and Siberian varieties, amoi*g 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, &e. 
—Also the pyrophysalite from Fahlun in Sweden, and the pycnite, 
formerly considered as a variety of beryl, are referable to topaz;—- 
chondrGdite (maclurite. brucite) from New Jersey, and from Pargas in 
Finland. 
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-carbonate of lead from Derbyshire, of which most rare sub¬ 
stance very perfect specimens will be found in this glass Case.— Chlo¬ 
ride of copper or atacamite, in crystallized splendid groups, chiefly from 
Remolinos, Solidad and Veta negra della Pampa larga, in Chili;—what 
was originally termed Peruvian green sand, or atacamite (being obtained 
