330 Elements of Mineralogy. 



been defcribed among the iron ores. Spe- 

 cies 19. 



SPECIES III. 

 Mneralized by Sulphur. 



7. Of this there are two Varieties, the 

 yellow and the red ; both are fublimable in 

 clofe veflels, detonate with nitre, with fixed 

 alkalis form a hepar, and are foluble in oils. 



I. VARIETY. 

 TclloiV) Orpiment. 



8. This is rarely found cryftalized. Baron 

 Born once found it in a polyhasdral form in a 

 blue clay in Hungary ; it is generally com- 

 pofed of fhining, flexible laminse like mica, 

 more or lefs folid ; its fpecific gravity is about 

 3,315; it contains only about ~ of its 

 weight of fulpfiur ; it burns with a blue flame, 



II. VARIETY. 

 Red,- Realgar^ Raufchgelbe. 



9. It is found either in fhapelefs or ftalacli- 

 tical mafles, opake or femi-tranfparent, or 

 tranfparent and regularly cryftalized in odlo- 

 haedral pyramids or prifms, and then called 

 ruby of arfenic\ its fpecilic gravity is 3,225, 



100 



