NATURAL HISTORY. 
[north 
m 
North America, which exhibits a considerable degree of 
flexibility: and another having the same property will be 
found among the singular varieties of magnesian limestone 
from the vicinity of Sunderland. Of the varieties of 
Werner’s brown-spar or pearl-spar , which in some cases 
is with difficulty distinguishable from rhomb-spar, several 
interesting specimens for figure, colour and lustre, are de¬ 
posited in this Case, and continued in 
Case 50, which is partly occupied by those fibrous 
varieties of brown spar, several of which were formerly 
referred to common fibrous limestone.— ■Carbonate of iron, 
or iron-spar, crystallized, fibrous,; massive, and botryoidal 
(sphcerosiderite of Hausmann).— Carbonate of manganese, 
in globular and botryoidal shapes of various shades of rose 
colour, on sulphuret of manganese, &c. 
The remainder of this glass Case is occupied by the 
several varieties of carbonate of zinc, (also called calamine, 
in common with the silicate of zinc in Case 26), crystal¬ 
lized, botryoidal, and in other forms, among which are the 
pseudomorphous crystals, derived from modifications of 
carbonate of lime. 
Case 51. In this Case are deposited the specimens of 
carbonate of lead, or white lead ore, among which are the 
delicately acicular varieties from the Hartz, accompanied 
and partly . coloured by green carbonate of copper; the 
crystallized varieties from Siberia, Mies in Bohemia; the 
pulverulent variety, &c. It also contains part of the 
specimens of carbonate of copper, viz* the blue copper, or 
copper-azure, the more remarkable varieties of which are 
those from Chessy, and from the Bannat, combined with 
various substances—the earthy varieties, some of which 
have been used as pigments under the name of mountain- 
blue ;—those crystallized varieties which, passing from the 
state of blue into that of green carbonate, have, by Haiiy, 
been called cuivre carbonate epigene. 
Case 52. Carbonates of copper continued : green car¬ 
bonates ; among which are the fine and rare varieties of 
fibrous malachite, in acicular crystals, and massive with 
fibrous structure and velvety appearance, accompanied by 
carbonate of lead, &c.; and, among the specimens of compact 
malachite, those characteristic and splendid ones from the 
Gumashevsk and Turja mines, in the Uralian mountains. 
