204 Notices of the Geology and Mineralogy of Steily. 
under the calcareous stratum covering the island. It is found 
in these cavities in every state of crystallization, from a 
granular or laminated mass to the finest fibres and points, 
shooting across or lining the cavity. Jt is always white, 
except in decomposed lavas, where its surface is stained 
by oxide of iron. ~ < ue 
Wagnesian Carbonate in opaque masses studded with 
rhomboids, in connexion with carbonate and sulphate of 
lime. Brown Spar, coating stalactites with yellowish 
three sided pyramids. In minute rounded crystals in the 
mines of Spathic iron, at Fume di Nist. 
Bituminous Carbonate, in masses of various sizes in the 
compact limestone, and in smal] pieces among the crystals 
of calcareous spar. The larger and harder masses are 
used in architecture as a black marble. Sometimes it is so 
impregnated with petroleum, as to be combustible; and 
the heat of the sun liquifies the petroleum, forming a miner- 
al pitch in the fissures, &c. 
Powder of Balda, a mixture of earthy carbonate and 
sulphur—formerly famous as a panacea. It has the usual 
properties of absorbents and sulphur. The earthy stratum 
1s almost universally Marl. The marls of Val di Mazzora 
are calcareous; those of Valdemone. siliceous and ferrugi- 
nous; and in the voleanic districts of Val di Noto, highly 
argillaceous and ferruginous. Indurated Marl is very com- 
mon; some of it is wrought as marble; it often forms im- 
mense masses, divided by regular fissures into prismatic 
blocks. Inthe mountains of Nicosia, &c. are strata of in= 
durated marl, containing petroleum 
Sulphate of lime is found in every Corner of Sicily, par- 
“ticularly at Raddusa and Paterno, in the plain of Catania 
and at Taormina. It forms entire mountains, subordinate 
to the limestone mountains. It is also imbedded in chalk 
and marl, and is found in veins in the shell limestone. In 
all these cases itis secondary. Primitive Gypsum is found 
in the granite of Pelorus. It generally occupies the beds 
of sulphur and salt so common in the island. A remarka- 
ble instance of the sulphur imbedded in chalk, and resting 
on sulphur, occurs at Raddusa. It is found in the forms of 
alabaster, fibrous gypsum, earthy and farinaceous gypsum, 
and selenite, or crystallized gypsum. Delicate white threads 
of gypsum are found occupying the cavities of lavas in the 
