Part III.—A. Chemical Trials.
1. Muriatic acid, hot or cold, produces no effect; hot nitro-muriatic dissolves the ore with energy, red fumes are evolved, and generally a red solution obtained, from which ammonia precipitates red oxyd of iron abundantly.
2. A heavy lemon-yellow powder remains, insoluble of course in acids, but easily and completely soluble in warm ammonia.
3. A dark powder, in diminished quantity, again appears, more acid dissolves it in part, and again reveals the yellow powder, which ammonia again dissolves, and so on, till nothing remains but some portion of the gangue.
4. The ammoniacal solution, which contains the oxyd of tungsten, is decomposed by acids, and by heat, and instantly deposits a white heavy powder, becoming yellowish by standing, and full yellow by heat.
5. This powder is infusible by the blow-pipe, but ignited with borax in a platinum crucible, it became of a superb blue, like smalt, or between that and Prussian blue.
6. The quantity obtained was too small to make it convenient to attempt its reduction to the metallic state; no doubt remained, however, that it was oxyd of tungsten, or as it is sometimes called, tungstic acid.
7. There were traces of manganese, and all the facts perhaps justify the conclusion, that the ore is very similar to the ferruginous tungsten or wolfram.
8. The calcareous tungsten occurs in octahedral crystals, but we have not before heard of this form in the ferruginous species, which generally affects the prismatic forms.