14 
saloon, ruby, oriental amethyst, oriental topaz, oriental 
Na^Thist. emerald) of the crystalline forms of which the 
principal modification? are here exhibited ; and 
the common or imperfect corundum from Bengal, 
Mysore, China (the diamant-spath of Werner)^ 
Lapland, &c. — As appendix to these are added 
the fibrohte (bournonite of Lucas), one of the 
concomitant substances of common corundum ; 
and the emery, which owes its hardness and con- 
sequent usefulness in polishing to an admixture 
of blue corundum.- — Among the many varieties 
of spinel we have the ceylonite or pleonaste, by 
some still considered as a distinct species, and 
the blue spinel from Aker in Sudermania. An- 
other substance nearly related to this species, is 
the automalite from Fahlun, in Sweden, or the 
spinel Ie zinci fere of Hauy : in one of the larger 
crystals the metallic particles are easily distin^ 
guished. — As chemically allied to the substances 
in this glass case is added the wavelite or hydrar-* 
giilite: the specimens of this mineral border on 
those of the prehnite (in the opposite case, No. 
11), to which species it was referred before its 
chemical composition was known. — Between the 
common corundum of this and the feldspar of 
the contiguous opposite glass case, is placed the 
andalusite, which was first considered as a con- 
gener of the former and afterwards referred to 
the 
