178 ACCOUNT OF A MINERAL SUBSTANCE. 



4. Tinfture of galls forms orange or deep yellow preci- 

 pitates. 



5. Unlike the other metallic acids, it refufes to unite with 

 ammonia. 



6. When mixed and diftilled with fulphur, it does not com- 

 bine with it fo as to form a metallic fulphuret. 



7. It does not tinge any of the fluxes, except phofphoric 

 acid ; with which, even in the humid way, it appears to have 

 a very great affinity. 



8. When combined with potafh and diffolved in water, it 

 forms precipitates, upon being added to folutions of tungftate 

 of potafh, molybdate of potafh, cobaltate of ammonia, and the 

 alkaline folution of iron. 



Thefe properties completely diftinguifh it from the other 

 acidifiable metals, viz. arfenic, tungften, molybdena, and chro- 

 mium; as to the other metals lately difcovered, fuch as ura- 

 nium, titanium, and tellurium, they are (till farther removed 

 from it. 



The colours of the precipitates produced by prufliate of pot- 

 afh and tincture of galls, approach the neareft to thofe afforded 

 by titanium. But the pruffiate of the latter is much browner ; 

 and the gallate is not of an orange colour, but of a brownifh 

 red, inclining to the colour of blood. JBefides, even if thefe 

 precipitates were more like each other, ftill the obftinacy with 

 which titanium refufes to unite with the fixed alkalis, and the 

 infolubility of it in acids when heated, fufficiently denote the 

 different nature of thefe two fubftances. 

 The iron Is in The iron in the ore which has been examined, is apparently 

 ftatt of brown j n ^ e f ame ftate as it is in wolfram, viz. brown oxide; and 

 this oxide is mineralized by the metallic acid which has been 

 defcribed, in the fame manner as the oxides of iron and man- 

 ganefe are mineralized by the tungftic acid or rather oxide. 

 For, from feveral experiments made upon a large fcale, I have 

 reafon to believe that in wolfram, the tungften has not attained 

 the maximum of oxidation. Several facls in the courfe of the 

 experiments lately defcribed, feem to prove, that this new me- 

 tal differs from tungften and the other acidifiable metals, by a 

 more limited extent of oxidation ; for, unlike thefe, it feems to 

 be incapable of retaining oxigen fufficient to enable the total 

 quantity to combine with the fixed alkalies. In § II. G. 2, 



this. 



