COMMON TALC. 91 
In consequence of the softness and tenacity of this 
stone, it can be turned upon a lathe, and otherwise 
cut and wrought with great ease. Hence, in Egypt, 
Lombardy, Norway, and other countries where it is 
found, it is formed into various kinds of culinary vessels 
and lamps, which harden in drying, and are capable of 
withstanding the strongest action of fire. Vessels of 
this description were known to the ancients ; and are 
particularly mentioned by Pliny, the Roman naturalist, 
who speaks of some that were highly wrought being 
very valuable. 
Potstone is used in some countries for the lining of 
stoves, furnaces, and ovens ; and it is so durable as to 
have, in some instances, stood unimpaired for several 
hundred years. 
On the banks of the Lake Como, there were some 
extensive quarries of potstone, which had been worked 
from the beginning of the Christian era. These quar- 
ries, however, fell in, on the 25th of August, ]618, and 
destroyed the neighbouring town of Pleurs; which had 
previously obtained by means of them an annual re- 
venue of about sixty thousand ducats. 
134. COMMON, or VENETIAN TALC, is an earth/ 
stone, capable of being divided into plates or leaves, which 
are soft and unctuous to the touch, somewhat transparent, and 
usually of greenish silvery white colour. 
It Leaves a white trace when rubbed upon any object. 
Mica and talc have a near resemblance to each other ; but 
the plates of the former, when bent, are elastic, while those of 
the latter are not. 
Venetian talc is very abundant in the Tyrol and the 
Valteline. In a state of powder it renders the skin soft 
and shining ; a property which appears to have sug- 
gested the idea of employing it as the basis of the 
cosmetic named rouge. This is prepared by rubbing 
together, in a warm mortar, certain proportions of car- 
mine, or extract of the flowers of carthamus tinctorius, 
