OHDER XJII. HEMI-PRTSMATIC SULPHUR. 49 



and the same species in most mineralogical works. Their 

 specific difference is obvious in several of their proper- 

 ties, in the measures of their angles, the character of their - 

 combinations, and particularly in their cleavage. Eminent 

 faces of cleavage, like those in the present species, never dis- 

 appear altogether in simple varieties, and may be observed 

 even in compound ones, though the particles, of composi- 

 tion be nearly impalpable. But no trace of such a cleav- 

 age exists in the following species, and this circumstance 

 will therefore always yield a sure and palpable, though 

 not the only character for distinguishing Orpiment from 

 Realgar. 



2. According to KLAPROTH and LAUGIER, the prisma- 

 toidal Sulphur consists of 



Sulphur 38-00 38-14. 



Arsenic 62-00 61-86. 



Its chemical formula As S 3 agrees with 39-08 of sulphur, 

 and 60-92 of arsenic. Before the blowpipe upon charcoal it 

 burns with a blue flame, and emits fumes of sulphur and 

 arsenic. It is soluble in the nitric, muriatic, and sulphuric 

 acids. 



3. The prismatoidal Sulphur is found in imbedded' no- 

 dules, more rarely in imbedded crystals in blue clay, and is 

 accompanied by hemi-prismatic Sulphur. In this way it is 

 met with at Tajowa near Neusohl in Lower Hungarv, in 

 the neighbourhood of Vienna, and probably also in Wal- 

 lachia, Servia, and other countries. At Kapnik In Tran- 

 sylvania, and Felsubanya in Upper Hungary, it occurs m 

 metalliferous veins with several species of Pyrites, Blende, 

 and Glance, with native Arsenic, and particularly with he- 

 mi-prismatic Sulphur. It is found likewise in Natolia, 

 China, and Mexico. 



5. It is used as a pigment. 



2. HEMI-PRISMATIC SULPHUR. 



Red Orpiment or Ruby Sulphur or Hemi-prismatic Sul- 

 phur. JAM. Syst. Vol. III. p. 451. Hemi-prismatic 

 vot. iii^ 



