126 
LONG 
GALLERY. 
Nat. Hist. 
Mount Vesuvius, with which are now combined seve¬ 
ral varieties of the ehzolite 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 se¬ 
veral others provisionally placed in this glass case, 
stand in need of further investigation as to their che¬ 
mical 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 as have 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 Mon¬ 
roe, in New York), which has but one axisand the 
lithia-mica , w 7 hich, besides the beautiful peach blossom, 
red, violet, greenish-grey, and white scaly varieties 
known by the name of lepidolite from Rozna in Mo¬ 
ravia, likewise comprises several large-foliated varieties 
of what was formerly considered as common mica, such 
as that from Zinnwald in Bohemia and Altenberg, ac¬ 
companied by apatite, tinstone, and topaz.—The spe¬ 
cies and varieties of the talcose substances are likewise 
very imperfectly understood. Among the specimens of 
talc in this glass case may be specified the common or 
Venetian(which enters into the composition ofcosmetics), 
and the indurated talc ; to the former of which may be 
referred the green radiated variety from Siberia, com¬ 
posed of distinct groups of small diverging laminae, and 
to which the name of pyrophyllite has lately been given; 
—agalmatolite (Werner’s bildstein, Haiiy’s talc gla- 
phique), employed by the Chinese for carving images, 
vessels, &c.;— chlorite , crystallized in aggregated, small, 
modified rhombic prisms; the earthy and foliated va¬ 
rieties, coating crystals of octahedral magnetic iron¬ 
stone, 
