AMERICAN MINERALS. 11.3 



when washed and calcined, weighed 0. 19 grammes 



on 5 grammes, or 8. 80 per 100. 



C The liquor (H.) was treated with an excess of 

 uomonia, an abundant precipitate was formed, part 

 of which was immediately re-dissolved by the am- 

 monia, and communicated to it a beautiful dark blue 

 colour, the residue appeared red, and after 21 hours 

 digestion it was separated from the ammoniacal li- 

 quor by Alteration, when washed and exposed to red 

 heat, it weighed 2. 16 grammes. A portion of this 

 precipitate was re-dissolved in muriatic acid, and 

 treated v\ itli an excess of ammonia, the copper was 

 thus found to have been completely separated. Ano- 

 ther portion was fused with caustic potash, but hav- 

 ing obtained no mineral cameleon, it was ascertain- 

 ed that the ore contained no manganese. Therefore, 

 the 2. 16 grammes were pure per-oxide of iron, but 

 as the mineral was magnetic, the iron must be esti- 

 mated in the state of a deutoxide, and the 2. 16 

 grammes of tritoxide are equivalent to 2. 108 gram- 

 mes of deutoxide, on 5 grammes, or 42. 16 per tOO. 



D. The ammouiacal liquor (C.) was boiled to 

 drive off the greater part of the excess of alcali, a 

 slight excess of sulphuric acid was then added to it 

 and a polished bar of iron, was allowed to remain in 

 it, until the liquor, when tested with sulphurated hy- 

 drogen, was found to contain no more copper. The 

 metallic copper thus precipitated, when well washed 

 and expeditiously dried, weighed 1. 95 grammes, 

 but from the colour of the ore, the copper must be 

 considered to exist in the state of a protoxide, and 

 the 1. 95 grammes of metallic copper, are equivalent 



