JOURNAL 



OP 



NATURAL PHILOSOPHY, CHEMISTRY, 



AND 



THE ARTS. 



yvLT 1798. 



ARTICLE I. 



Memoir on a New Metallic Acid -which exijit in the Red Lead of Siberia. By VAU^SLIlfii 

 EKtraEledfrom the Bulletin of the Soc. Philom.* 



B 



Y a new examination of the red lead of Siberia, Vauquelin is convinced that this mi- 

 neral contains a metallic acid very difFerent from all thofe which have hitherto been known. 

 The following are the principal refults of his experiments : 



The red lead ore was reduced to fine powder, and boiled in a faturated folution of car- 

 bonate of potafli. An effervefcence of confiderable duration was produced ; the powder 

 was diffolved, but foon afterwards a precipitate fell down of a yellowifli white colour. The 

 folvent had aflumed a beautiful golden colour. 



The precipitate proved to be carbonate of lead. 



Nitric acid was poured into the alkaline fluid till the excefs of carbonate of pota'fli was 

 faturated. The fluid exhibited an orange-red colour. It was then mixed with a fo. 

 lution of tin, recently prepared, with which it aflumed a brown colour, that afterwards 

 became greenilh. When poured into a nitric folution of lead, it immediately generated 

 the red lead. By fpontaneous evaporation, it afforded cryflrals of a beautiful orange red, 

 befides thofe of the nitrate of potafli. 



The nitric acid being poured into the folution of the red cryftals occafioned no preci- 

 pitate ; but when, after evaporation to drynefs, the cryftals of nitrate of potafh, which rc- 



. * This abftraft is tranflated from the Journal de Phyfique, bearing date for Nov. I794, but lately printed. 



Vol. IL— July 1798. U mained 



