pTOcefs for r-efolvwg Minerals ly AlkaUss. 247 



ulecompofed. The white precipitate, wafhed and dried, 

 weighed one ounce fix drams. 



The leys, when evaporated, produced three ounces five 

 drams of phofphoric tartar. This fait, when expofed to heat 

 in a crucible, liquefies, fwells up, and becomes fufed. If it 

 be poured on a plate of iron, it has the tranfparepcy of glafs 

 as long as it is warm, but becomes white and opake on cool- 

 ing. This fait when fufed is fapid, and foluble in water: jt 

 lofes by fufion three-eighths of its water of cryllallifation. 



In the decompofition of the vitrifiable phofphoric acid fait 

 by fixed alkali, more than half of the alkali is decompofed; 

 lince there are obtained no more than three ounces fivedran^s 

 of phofphoric tartar, which contain three eighths of water. 



The portion of ac'tdura pingue, the principle of the fixed 

 alkali*, which modifies itfelf into mephitic acid gas, is very 

 fmall. This ac'idum pingue combines with the animal earth, 

 and confliitutes calcareous earth, which faturates itfelf with 

 phofphoric acid, and forms the infolublp fait above meur 

 f ioned f. 



X. Account of a new, eajj, and niore convenient Procefs Jof 

 rejhlving Alinerals by Alkalies. By M. LowiTZ %. 



JL HE decompofition of mineral bodies is, without doubt^ 

 one of the mofl: difficult and moft laborious operations of 

 chemiftrv, and which muft ftill become more difficult and 

 complex in proportion as we are acquainted with a greater 

 pumber of new and component parts in foffil bodies; for 

 «very new difcovercd earth or fpecics of metal requires after- 



* V\'lien fixed alkali is employed for the precipitation of any fubftancc, 

 there is always a part of tiie alkali decompofed, and the acid and eanh 

 -contained in it form part of the precipitate. Of tiiis, rncrcurv difengaj;ed 

 from «hc nitrous cid by fixed alkali aftnrds an inl^ancc. If this precipi- 

 tate be diftilicd, it is fublimate I into a mercurial fair fut gtnaii. Tbfi 

 earth of the alkali 1 emains at the bottom of the retort. 



t In the above curious paper the author's own nomenclature has been 

 followed. Edit. 



* From CrcU's Chemical Annalt, 1799, Vql. II. pan io» 



watd;*. 



