168 NATURAL HISTORY. [NORTH 
no chemical analysis has as yet been given of it_A suite of specimens of 
comptonite from Vesuvius, lining the cavities of a pyroxenic lava, &c. 
accompanied by gismondine and other crystallized substances ;— gmeli- 
nite or hydrolite ;— levine> and some other new species of this extensive 
family of minerals. 
Case 29. To the same family belongs the harmotome or cross stone, 
divided into baryte-harmotome and potass-harmotome, to which latter 
are to be referred the Vesuvian minerals called zeagonite , gismondine , 
abrazite, and also the philipsite. 
The remainder of this Case is occupied by species of the feldspar 
family .—Common feldspar, variously crystallized and massive: among 
the specimens here deposited may be specified—the fine green variety 
from Siberia, called amazon stone ; the beautiful large crystals from 
Baveno ; feldspar with embedded crystals and fragments of quartz (gra¬ 
phic stone, graphic granite), from Siberia, &c .;—Labrador feldspar 
(also called opalescent feldspar, being remarkable for its beautiful play 
of colours), chiefly from the coast of Labrador and from the transition 
syenite of Laurwig in Norway ;—adularia or naker feldspar, principally 
found on mount St. Gothard, but not in the valley of Adula from which 
its name is derived : the fine variety from Ceylon, when cut en ca - 
bochon, is called moon-stone; an da yellow naker feldspar with reddish dots 
has obtained the name of sun-stone, which is also sometimes given to 
the beautiful avanturino variety of common feldspar placed in this glass- 
case. 
Case 80. Feldspathic substances continued — ice-spar and sanidine 
or glassy feldspar, both nearly allied to common feldspar; albite or 
cleavelandite , the finest specimens of which are those from Dauphine 
and Siberia ; and pericline , united by some mineralogists with the pre¬ 
ceding species, from St. Gothard, Tyrol, &c. ;—anorthite from Vesu¬ 
vius ;— oligloca.se , also called natron-spodumen—together with some 
other species separated, perhaps unnecessarily, from common feldspar 
and cleavelandite ;—Ieucite or amphigene, chiefly from Vesuvius, in 
separate crystals of various sizes and degrees of transparency, massive, 
embedded in pyroxenic and other lavas ;—triphane or Spodumen and 
petalite: substances in which lithia, or the oxide of lithium, was first dis¬ 
covered by Arfvedson. 
Case 31. This Case contains— nepheline , from Mount Vesuvius, 
with which are now combined several varieties of the elceolite or fettstein 
of Werner ;— wernerite, under which name, formerly confined to some 
varieties of common and compact scapolite, are now united the meionite 
of Vesuvius, and the greater part of the scapolite of Werner, the 
paranthine and also the dipyre ; substances which, together with several 
others provisionally placed in this glass Case, stand in need of further 
investigation as to their chemical and crystallographical characters. 
Case 32 contains micaceous and talcose substances. Our imperfect 
knowledge of the optical properties and chemical constitution of many 
varieties of the former, does not admit of their being arranged according 
to those distinctive characters ; such varieties as haye been more closely 
examined in this respect, may be divided into potassa-mica (by far the 
most common), which has two axes ; magnesia-mica (from Vesuvius, 
Siberia, and Monroe, in New York), which has but one axis ;—and the 
lithia-mica , which besides the beautiful peach-blossom, red, violet. 
