THE ARSEXIC GROUP. 99 



Color and streak tin- white, but usually dark grayish from 

 tarnish. Brittle. H.=3*5. G. =o -65-5 -95. 



B.B. volatilizes very readily before fusing, with the odor 

 of garlic : also burns with a pale bluish flame when heated 

 just below redness. 



Obs. Occurs with silver and lead ores. It is found in 

 considerable quantities at the silver mines of Freiberg and 

 Schneeberg ; also in Bohemia, the Hartz, at Kapnik in 

 Upper Hungary, in Siberia in large masses, and elsewhere. 



In the United States it has been observed at Haverhill 

 and Jackson, X. H., and at Greenwood, Me. 



Orpiment. — Yellow Arsenic Sulphide. 



Trimetnc. Cleavage highly perfect in one direction. In 

 foliated masses, and sometimes in prismatic crystals. Color 

 and streak fine yellow. Lustre brilliant pearly, or metallic 

 pearlv, on the face of cleavage. Subtransparent to translu- 

 cent ; sectile. H. = 1 -5-2, G. = 3 -4-3 -5. 



Composition. As 2 S 3 = Sulphur 39*0, arsenic 61-0. Wholly 

 evaporates before the blowpipe with an alliaceous odor, and 

 on charcoal burns with a blue flame. 



From Hungary, Koordistan in Turkey in Asia, China, and 

 South America/ Occurs at Edenville^ X. Y., as a yellow 

 powder, resulting from the decompositon of arsenical iron. 



Realgar is another arsenic sulphide. It has a fine clear red color, 

 aurora red to orange, and occurs transparent or translucent ; H. = 

 15-2 ; Gr. =3 35 -3 05 ; Composition, As S= Sulphur 29 9, arsenic 701. 

 Like the preceding before the blowpipe From Hungary, Bohemia, 

 Saxony, the Hartz, Switzerland, and Koordistan in Asiatic Turkey. 

 It has been observed in the lavas of Vesuvius. 



Realgar is one of the ingredients of white Indian five, often used as a 

 signal light. Orpiment is a coloring ingredient in the pigment called 

 king's yellow, in which it is mixed with arsenious acid. 



Arsenolite. — White Arsenic. 



Isometric. In minute capillary crystals, and botryoidal 

 or stalactitic. Color white. Soluble ; taste astringent, 

 sweetish. H. =1-5. G. =3-7. 



Composition. As. 2 3 = Arsenic 75*8, oxygen 24-2 = 100. 



This is the same compound with the common arsenic of 

 the shops. It is found but sparingly native, accompanying 

 ores of silver, lead, and arsenic in the Hartz, Bohemia, and 

 elsewhere. It is a well-known poison. 



