NATURAL history. 
109 
<5ALLERY.] 
—The species and varieties of the talcose substances are 
likewise very imperfectly understood. Among the Speci¬ 
mens talc in this glass Case may be specified the com¬ 
mon or Venetian (which enters into the composition of cos¬ 
metics), and the indurated talc; to the former of which 
may he referred the green radiated variety from Siberia, 
composed of distinct groups of small diverging laminae, 
and to which the name oi pyrophyllite\id^% 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 varieties, 
coating crystals of octahedral magnetic iron-stone, &c.;— 
pinite, crystallized in regular hexagonal prisms, and gie- 
seckite, from Greenland, which appears to be a variety of 
this species. — Fahlunite, under which name several dis¬ 
tinct substances have been noticed by authors. 
Case 33. This and part of the following Case chiefly 
contain substances related to hornblende or amphibolic 
minerals, among which may be specified the basaltic and 
common hornblende, including the pargasite ; —the actino- 
lite or strahlstein (divided by Werner into the glassy, 
common, and fibrous varieties) —the gramma tile or tremo- 
lite (so called from Val Tremola, where, however, it is 
not found), among the specimens of which are the fine, 
fibrous varieties, resembling asbest; the glassy tremolite, 
in dolomite and granular limestone, &c.— Arfvedsonite — 
Anthophyllite, 
Case 34. Part of this Case is filled Avith 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 observed specimens illus¬ 
trative 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 andschiller- 
asbest, mountain Avood, mountain cork, or nectic asbest, 
&c., separate, and in combination with other substances; 
—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 imbedded in lava from Vesuvius, together with 
