50 



Chemical Analysis of certain Minerals, 



WaUr—'?\'0(\v\ce.dL opalfs - ence (antimonv). 



Prusnate potash — Emerald green, changing to blue when precipitated. 

 Ammonia— floceulent precipitate. 



Hydrosidijhurale of «mwow'a— Greenish, changing j^ellowish brown. 

 Tincture (jails — No effect : next day settled into a floceulent brownish 



yellow precipitate, 

 Phofphate soda — Slight white floceulent precipitate. 

 Sulphate of iro7i — Slight dust-like precipitate. 

 Oxalic ac'id — Mimale of tin— no effect. 



The precipitate C contained sulphur, which wiis burned off, leaving a 

 black resi'iuum, which by deflagrating with saltpetre, indicated tl:e 

 presence of carbon in some sliaj-e. The re.sidunm after deflagration 

 was washed, and 2 or 3 minute globules of silver collected ; also another 

 minute metallic globule, and a little silex, and eartijy matter. 



The sn^all nieiallic globule was «o minute that it required to be exa- 

 mined by the microscope, and admitted only of two tests being applied 

 to it. 1 he examination resulted as follows. Colour, dark iron grey ; 

 lustre, dull, metallic ; streak, a lighter grey of dull lustre ; malleable ; 

 harder than silver ; insoluble in nitric, but soluble in nitro-murialic 

 acid : — this solution was tested with, 



Hydro.sulphuret of ammonia— ^Ydah gave a dark green colour, which 

 turned into a black precipitate, leaving the solution tinged 

 olive. 



Prussiate of polash, — gave an emerald green colour. 



I may here state that two minute metallic grains were picked out 

 of the menachanite, No. 2, which proved as before seated to be silver ; 

 and a third grain soluble only in nitro muriatic acid, whi ;h being tested 

 as for platina, and compared with a solution of plalina foil, gave indica- 

 tions as follows : — 



Metallic grain. Plutina foil. 



Muriate of ammonia no change no change. 



Old muriate of tin dark brown passing to lilac, yellowish brown. 



Fresh made do lilac lilac. 



Prnssiate potaji bluish green lighter bluish green. 



