136 ACCOUNT OF A MINERAL SUBSTANCE. 



^hof^cif" by 6 ' A fmal1 «l uantit y of P h ° r P hor ic acid, being added to the 

 muriatic folution, in a few hours formed a white flocculent 

 precipitate. 



ar^d by alkalis. 7. potafti, foda, and ammonia, alfo produced white floc- 

 pulent precipitates, which were not rediflblved by an excefs 

 of the alkalis, unlefs the liquors were heated; and, in that 

 cafe, part was diffolved by the fixed alkalis, but not by am- 

 monia. 



Muriates of 8. The muriatic folution did not yield any precipitate, when 



hide, magnefia, t k e mur i a tes of lime, magnefia, and ftrohtian, were added ; 



andftrontian, . " • . ' .' * 



g^ve no precip. but muriate ot barytes formed a flight cloud. 



Zinc threw 9. When a piece of zinc was immerfed in the muriatic fo- 



down white lution, a white flocculent precipitate was obtained *. 



F. 



Acetous acid The acetous acid has not any apparent effect on the white 



thTw^Tteln^ P reci P itate i when lop S digefted with it. 



**;'" ' q. 



fixed alkalis The fixed alkalis readily combine with this fubftance, both, 



wti iI i y t combin ' in the dr y and in the humid wa ^- 



We have already feen, that the former method was em- 

 ployed with fuccefs in the analyfis of the ore ; and the experi- 

 ments made with the blow-pipe may be regarded as an addi- 

 tional confirmation. In each of thefe cafes, the white preci- 

 pitate combined with the alkali, as foon as the heat was fuffi- 

 cient to caufe the latter to flow ; and, when a carbonate was 

 employed, a portion of carbonic acid was expelled. 



The carbonic acid was in like manner difengaged ? when 

 the white precipitate was boiled with lixivium of carbonate of 

 potafti, or of foda ; and the folutions thus prepared, refembled 

 in every refpect thofp which were formed by diflblving in 

 water the falts which had been produced in the dry way. 



It will be proper here to give a more particular account of 

 thefe combinations. 

 Humid folution J * Some of the white precipitate was digefted, during nearly 

 in pota/h : a one hour, with boiling lixivium of pure or cauftic potafti : 



portion left, 



* This appears to indicate the obftinacy with which this fub- 

 ftance retains a certain portion of oxigen; for we here fee that zinc 

 does not precipitate it in the metallic flate, but only reduces it to an 

 ;nfo}uble oxide. 



about 



