NATURAL HISTORY. 
57 
GALLERY.] 
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 crystaliographical 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 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 Monroe, in New York), which has but one axis ;—and the 
lithia-mica , which besides the beautiful peach-blossom, red, violet, 
greenish-grey, and white scaly varieties known by the name of lepidolite , 
from Rdzna in Moravia, likewise comprises several large-foliated va¬ 
rieties of what was formerly considered as common mica, such as that 
from Zinnwald in Bohemia and Altenberg, accompanied by apatite, tin¬ 
stone, and topaz. ( Several of these are referable to the silicates com¬ 
bined with fluorides, in Case 58 a.) 
The species 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 of cosmetics), and the indurated talc; to the 
former of which may be referred the green radiated variety from Siberia, 
composed of distinct groups of small diverging laminae, and to which 
the name of pyrophyllite is commonly given ;— agalmatolite , (Werner’s 
bildstein, Haiiy’s talc glaphique,) employed by the Chinese for carving 
images, vessels, &c. ; - chlorite, crystallized in aggregated, small, modi¬ 
fied rhombic prisms ; the earthy and foliated varieties, coating crystals 
of octahedral magnetic iron-stone, &c. ;— pinite, crystallized in regular 
hexagonal prisms, and gieseckite, from Greenland, which appears to be 
a variety of this species.— Fahlunite, under which name several distinct 
substances have been noticed by authors. 
Case 33. This and part of the following Case chiefly contain sub¬ 
stances related to hornblende or amphibolic minerals, among which may 
be specified the basaltic and common hornblende , including the parga - 
sitei —the actinolite or strahlstein (divided by Werner into the glassy, 
common, and fibrous varieties);—the grammatite or tremolite (so called 
from Val Tremola, where, however, it is not found), among the speci¬ 
mens of which are the fine, fibrous varieties, resembling asbest; the 
glassy tremolite, in dolomite and granular limestone, &c_ Arfvedsonite 
—A nthophyllite. 
Case 34. Part of this Case is filled with the mineral substances 
called asbestine , many of which appear to pass into some of the varieties 
of amphibole in the preceding glass Case. Among these may be ob¬ 
served specimens illustrative of the transition from a very close to a loose- 
fibrous structure ;—several varieties of the flexible asbest or amianth , 
with some antique incombustible cloth, paper, &c., made of it;—the 
varieties called common and schiller-asbest, mountain wood, mountain 
cork, or nectic asbest, &c., separate, and in combination with other sub¬ 
stances ;—the blue and yellow asbest from South Africa, to which 
the name of krokydalite has been given. The remainder of this 
Case contains pyroxenic minerals:— augite , in separate crystals, and 
d 3 
