30 THE PROSPECTOR'S HANDBOOK. 



Incrustation without reduced metal : 



yellow when hot ( . 



white when cold } " ino ' 



4. On charcoal, with carbonate of soda : 



Same as in 3. 



5. On platinum wire with borax : 



Consult Table A. 



6. On platinum wire with microsmic salt: 



Consult Table B. 



7. Heated on platinum wire moistened with hydrochloric acid : 



Flame colour: blue = copper (afterwards green), lead, anti. 

 mony, arsenic, selenium ; green = copper, also molybdenum, 

 barium, phosphorus, &c. 



8. On charcoal with nitrate of cobalt solution : 



Green mass = oxides of zinc, antimony, tin, &c., &c. 



Confirmatory tests when the mineral has been treated 

 alone on charcoal or with carbonate of soda : 



(i.) When metallic beads or spangles are left : 



Silver. If dissolved in nitric acid, an addition of hydro- 

 chloric acid or a solution of common salt will precipitate 

 white chloride of silver. 



Gold. If dissolved in 4 parts hydrochloric acid and 

 1 part nitric acid, a precipitate of purple of Cassius will be 

 obtained when protochloride of tin is added. 



Copper. If treated with borax on platinum wire it will 

 give reactions, as in Table A. 



(ii.) When a grey or blackish residue is left : 



Heat the residue with borax on platinum wire and note 

 the colour of the bead; compare results with Table A, for 

 COBALT, COPPER, IRON, NICKEL. 



(iii.) When the mineral yields an incrustation on the 

 charcoal : 



Antimony. If the scraped-off incrustation be treated 

 with hydrochloric acid and zinc on a piece of platinum foil, 

 a black film of antimony is formed. 



Lead. If dissolved in nitric acid, the excess of acid 

 evaporated and a little sulphuric acid be added, a white 

 powder will be formed. 



Tin. If dissolved in hydrochloric acid, a grey precipitate 

 is formed when metallic zinc is placed in the solution. 



