198 NORTH GALLERY. [UPPER 
Div. IV. zirconates, and stannates, thus link the silicates to the molybdates 
° a ?i!9 1 anc * tur >g states > an( i these, in turn, are followed by the class of 
an ' chromates and the sulphates. The suite of specimens of Perofskite 
from Siberia, the crystals of Eudyalite, of Columbite, of Fergusonite, 
and the specimens of Tscheffkinite, are especially observable for their 
excellence or their rarity. 
3ases 53 to Among the anhydrous species in the sulphates, attention may be 
55, called to the specimens of Celestine (strontium sulphate) from near 
Bristol, and to the Anglesite (lead sulphate) from Pennsylvania and 
from Monte Poni. Gypsum, or Selenite, the hydrated calcium sul- 
phate, is an important mineral as yielding Plaster of Paris by the 
expulsion of its water. A magnificent specimen of this mineral, as 
remarkable for its size as for the grouping of its crystals, presented by 
His Royal Highness the late Prince Consort, ornaments a window in 
Boom II. It was found at Reinhard's-brunn, Saxe-Coburg. 
3ase 57. Adjoining these are a few minerals of the greatest rarity and inte- 
rest. The crystals of Linarite are unique, and the specimens of Cale- 
donite and Lanarkite, of Leadhillite, an oxy-sulphate of lead, and 
of the rare mineral Connellite, are among the finest known of these 
British species. 
)ases 56 to The borates and the class of nitrates occupy part of Case 56 ; and 
*Q. thence to Case 60, the Cases are occupied by the class which includes 
the phosphates and arsenates, in which the isomorphism of the corre- 
sponding compounds of the arsenoid element Phosphorus, and of 
Arsenic, is so complete that the salts of their acids cannot be well 
classified apart from each other. With these also the Vanadates find 
their place, as being isomorphous with them. 
Here may be seen fine crystals of Erythrine, the beautiful cobalt 
arsenate; specimens of Haidingerite (Case 57), and of Erinite (Case 
57); crystals of Lazulite (Case 58); very fine suites of Uranite (phos- 
phate of Copper and Uranium), and of Autunite ; the beautiful blue 
Cornish mineral Liroconite; and splendid specimens of Apatite, 
Mimetesite, and Pyromorphite. 
3rv. V. Division V., occupying two half Table-Cases in Room I., is consti- 
Jase 60. tuted by certain organic compounds, which as occurring in the earth with 
constant and definite characters, independent of organic structure, find 
their place in a Mineral Collection. Among these, Amber, in ancient 
times ranking in value with the gems, is here exhibited in a large 
series of specimens. 
In Room II. will be seen two half Table-Cases adjoining the wall, 
in which is arranged an extensive and instructive series of pseudo- 
Drv. VI. morphous minerals forming Division VI. They illustrate the decom- 
posing influences to which many minerals have been subjected, and 
they throw valuable light on the order of succession in which, and 
the conditions under which, particular minerals have been formed and 
deposited. 
NEVIL STORY-MASKELYNE. 
