616 MANUAL OF NATURAL HISTORY, 



light steel-gray; 2, with Platinum as 

 "Platin-Iridium/' in small grains, sp. gr. 

 = 16-17, white. Fusible only before the 

 oxy-hydrogen blowpipe. Solutions of its 

 salts present varied colours. Symb. Ir. 



2. Family. — Osmiides. Minerals containing Os- 



mium. Occur with ores of Iridium, and 

 Platinum, sp. gr. = 7. Fusible before the 

 oxy-hydrogen blowpipe. Forms with oxy- 

 gen a volatile acid, with a pungent smell 

 resembling that of chlorine. Symb. Os. 



3. Family. — Vanadiides. Minerals containing com- 



pounds of Vanadium. Occur as Vanadic 

 acid combined, 1, with lead or "Vanadinite/' 

 hexagonal, H. = 2*5 — 3, sp. gr. = 6'9, brown- 

 ish-yellow ; 2, combined with iron or with 

 copper. Dissolves in Nitro-hydrochloric acid ; 

 forms coloured solutions. Symb. V. 



4. Family. — Telluriides. Minerals containing 



Tellurium, either native or in combination. 

 Occur 1, pure as "Native Tellurium/' lamellar 

 or granular, H. = 2 — 2*5, sp. gr. = 6*2, white; 

 2, in combination with other metals as gold 

 or "Graphic Tellurium/' prismatic, H.= 1*5-2, 

 sp. gr. 5'7— 8*2, gray; also with bismuth, 

 silver, and lead. Tellurium volatizes before 

 the blowpipe, emitting no odour. Symb. Te. 



5. Family. — Bismuthides. Minerals containing 



Bismuth either native or variously combined. 

 Occur 1, pure or "Native Bismuth/' rhom- 

 bohedral; H. = 2 — 2*5, sp. gr. = 9*7; reddish- 



