GALLERY.] natural history. (Minerals.) 71 
, Case 31. Other mineral substances of the preceding section here 
deposited, are, the baulite, the triphane or spodumen and the petalile : in 
which latter substance lithia was first discovered by A rfvedson •— the 
davyne of Monticelli ;— the nepheline , from Mount Vesuvius’ with 
which are now combined several varieties of the elceolite or fettstein of 
Werner ;— the wernerite, under which name, formerly confined to some 
varieties of common and compact scapolite, are now by most mineralo- 
gical writers united the meionite of Vesuvius, and the greater part of 
the scapolite , the paranthine , the dipyre , the nuttallite, the bergmannite , 
the rosellile, and the amphod elite ; substances which, together with several 
others provisionally placed in this Case, stand in need\>f further investi- 
gation as to their chemical and crystaliographical characters. 
Case 32 contains chiefly 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 , which 
has but one axis : in characteristic specimens from various localities, 
particularly from Vesuvius, where it occurs in small, but briliiant and 
transparent six-sided prismatic crystals; and lithia-mica, which besides 
the beautiful peach-blossom, red, violet, greenish-grey, and white scaly 
varieties known by the name of lepidolite , (some varieties of which, how- 
ever, are referable to the silicates combined with fluorides, in Case 58 A,) 
from Rozna in Moravia, also comprises several large-foliated varieties 
of what was formerly considered as common mica, such as that from 
Zinnwald in Bohemia and Altenberg, accompanied by apatite, tinstone, 
and topaz. The species and varieties of the talc-like substances are like- 
wise very imperfectly understood. Among the specimens of talc in this 
Table 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 probably be referred the green radiated talc from Siberia, 
composed of distinct groups of small diverging laminse, and which is 
known under the name of pyrophyllite pot stone, ollite, or lavezzo, (the 
lapis comensis of Pliny,) which appears to be an intimate mixture of 
talc and asbest, chiefly from Chiavenna, near Como, where it is 
manufactured into culinary vessels ; — chlorite, crystallized in ag- 
gregated, small, modified rhombic prisms : the earthy and foliated 
varieties, coating crystals of octahedral magnetic iron-stone, &c. 
Other related mineral substances are the ripidolite ; — the pennine ; 
— the scarce leuchtenbergite from the Ural, the composition of which 
appears to approach near to that of chlorite -the gieseckite, from 
Greenland ; — the oosite, fahlunite or triclasite, from Fahlun in Sweden : 
this latter mineral substance, however, together with the weissite, the 
chlorophyllite, the praseolite, the aspasiolite, the bonsdorjite, as also 
several varieties of the pinite in this Table Case, are now by some 
mineralogical writers considered as only metamorphoses of cordierite 
(Case 36). 
Case 33. This and part of the following Case chiefly contain 
amphibolic and pyroxenic and related minerals, among which may 
be specified the basaltic and common hornblende, including the parga- 
site ; — the actinolite or strahlstein (divided by Werner into the glassy. 
