FLOOR,] 
MINERALS. 
45 
latter consist of the metallic alloys of iron and nickel with small 
amounts of other metals, known as " meteoric iron." They also contain 
mechanical admixtures of compounds of these metals with phosphorus, 
and also with sulphur. Among the specimens of the former class, is 
the mass found at Breitenbach in Bohemia, in 1861. It contains Silica 
crystallised as Asmanite in the orthorhombic system, associated with 
a ferriferous Enstatite (Bronzitej, that is in some cases well crys- 
tallised. The crystalline structure of the meteoric iron masses is 
effectively shown by the etching of their polished surfaces. In this 
case are seen two small but very interesting iron meteorites, the falls 
of which were witnessed ; the one on Jan. 23, 1870, at Nedagolla, in 
Vizagapatam, India ; the other at Rowton, in Shropshire, on the 20th 
of April, 1876. On the north side of this room is the vast mass 
of meteoric iron found at Cranbourne, near Melbourne, in Australia, 
presented by James Bruce, Esq., and weighing above 3| tons. At 
the east end of the gallery is one weighing l,4001bs., presented by 
Sir Woodbine Parish, found on the Gran Chaco, South America ; and 
adjoining it is another mass cf iron of nearly 5 cwt., from the Desert 
of Bolson de Mapimi, Mexico, supposed to have fallen in 1837. 
The Collection of Minerals is arranged in four principal Divisions. 
These are — 
Division I. The Native Elemeuts. Cases 1, 2, 3, 4 (i.) 
Division II. The Compounds of Metals, with elements of the Arsenic 
Group (the Arsenoid elements, viz. Bismuth, Anti- 
mony, and Arsenic); or with elements of the Sulphur 
Group (the Thionids, viz. Tellurium, Selenium, and 
Sulphur) ; or with elements belonging to both groups. 
Cases 4 (ii.) to 12 inclusive. 
Division III. The Compounds of Metals with elements of the Chlo- 
rine Group (the Halogen elements — Iodine, Bromine, 
Chlorine and Fluorine). Cases 13 and 14. 
Division IV. Compounds of elements with Oxygen. Cases 15 to 60. 
These Divisions are again subdivided into sections and classes, the 
latter embracing the minerals which fall under the same general 
chemical denomination; as, for instance, the salts of the same acid or of 
a group of acids chemically and crystallographically equivalent to each 
other. Each class is further separated into distinct chemical series, 
the minerals included in any series being such as are designated bv 
the same or equivalent typical formula?. Subordinated to this chemical 
systemof classification is the final distribution of the several homotypical 
species of each chemical series, into distinct crystallographic series, 
arranged according to the crystalline system to which they belong ; the 
order of sequence of these systems being — 1st, the Cubic System ; 2nd, 
the Dimetric or Pyramidal System ; 3rd, the Trimetric or Ortho- 
