PHYSIOGRAPHY. 217 



Sulphur. 



Lustre resinous. Color, several shades of sulphur-yel- 

 low, inclining sometimes to red or green. Streak sulphur- 

 yellow, passing into white. Transparent . . . translucent on 

 the edges. 



Sectile. Hardness = 1-5 ... 2-5. Sp. gr. = 2-072. 



Compound Varieties. Twin-crystals : axis of revolu- 

 tion perpendicular, face of composition parallel to a face 

 of r. Imbedded globules : surface uneven ; composition 

 impalpable, often impure. Massive : composition granu- 

 lar, often impalpable, strongly coherent ; fracture uneven, 

 even, flat conchoidal. Sometimes pulverulent. 



1. Sulphur as it occurs in nature is pure, or is only mixed with bitu- 

 men or clay. It acquires resinous electricity by friction, is easily in- 

 flammable, and burns with a blue or white flame, and a pungent smell 

 of sulphurous acid. It is insoluble in water, but unites readily with 

 potash or soda. It may be obtained crystallized by sublimation, or still 

 more easily from solutions in liquids. The forms of sulphur, crystalli- 

 zed from fusion, are incompatible with those of the present species. 

 They are generally oblique rhombic prisms of 90 J 32', the terminal face 

 of which is inclined to the obtuse edge of the prism, which is itself com- 

 monly replaced at an angle of 95 46 / . It occurs almost always in reg- 

 ular compositions. The crystals are at first transparent, but they soon 

 become opake. 



2. Sulphur is generally met with in beds of Gypsum or in the accom- 

 panying strata of clay. It is generally associated with Calcareous Spar 

 and with Celestine. It occurs in veins with Copper Pyrites, Galena, 

 and Orpiment. It is deposited from several thermal springs and in large 

 quantities from volcanos ; sometimes it occurs in beds of Bituminous 

 Coal. 



3. Sulphur is found in splendid crystals and pure massive varieties, 

 also, in globular concretions, (which however, are seldom without earthy 

 or bituminous admixtures) in Sicily, and several provinces of Italy. It 

 occurs in imbedded spheroidal masses of a brown color, which is owing 

 to bitumen at Radoboy, near Crapina in Croatia. Near Cracovia in 

 Poland, it is likewise met with more or less in pure massive varieties 

 and small crystals. The finest crystals, excepting those from Sicily, 



VOL. II. . 19 



