226 METALS. 



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

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



In the United States, it has been observed at Haverhill, 

 N. H., in mica slate, and also at Jackson in the same state. 



The name arsenic is derived from the Greek arsenikon^ 

 or arrenikon, masculine, a term applied to orpiment, a sul- 

 phuret of arsenic, on account of its potent properties. 



white arsenic. — Arsenous Acid. 



In minute capillary crystals, and botryoidal or stalactitic. 

 Color white. Soluble; taste astringent, sweetish. H = 

 1*5 — Gr = 3'7. Composition, arsenic 75*8, oxygen 24*2. 



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. 



Uses. It is a well known poison. 



Pharmacolite, is an arsenate of lime, occurring in white or grayish 

 crystals. H=2— 25 ; Gr=26— 28. 



Haidingerite. Haidingerite is another arsenate of lime. 



SULPHURETS OF ARSENIC. 



There are two sulphurets of arsenic. 



Orpiment or the yellow sulphuret of arsenic. In foliated 

 masses, and sometimes in prismatic crystals, 

 with a perfect diagonal cleavage. Color and 

 streak fine yellow. Luster brilliant pearly, 

 or metallic pearly on the face of cleav- 

 age. Subtransparent to translucent : sectile. 

 H=l*5 — 2. Gr=3-4 — 3*5. Composition, 

 sulphur 39*0, arsenic 61 '0. Wholly evapo- 

 rates 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, N. Y., as 

 a yellow powder, resulting from the decomposition of arseni- 

 cal iron. 



Realgar, or Red sulphuret of arsenic. In oblique prisms, 

 and also massive : cleavage much less perfect than in orpi- 

 ment. Color fine clear red, aurora red to orange. Luster 

 resinous. Transparent to translucent. H=l*5 — 2. Gr = 



What is while arsenic? What are the characters of orpiment I 

 *vhat of realgar 9 



26* 



