896 Intelligence and Miscellaneous Articles. 



nitric acid, dilute the solution and precipitate with excess of ammo- 

 nia the phosphates of lime, zirconia, iron and alumina (A). The 

 filtered liquor is concentrated, and a fragment of sal-ammoniac is im- 

 mersed in it, with the addition of a few drops of ammonia. The 

 vanadium is immediately precipitated in the state of vanadiate of 

 ammonia, which is to be collected on a filter and washed, at first with 

 a saturated solution of sal-ammoniac, and then with alcohol. The 

 solutions containing sal-ammoniac are evaporated and the residue 

 slightly calcined. Water is then to be added, which separates a 

 little silica, and the phosphoric acid is to be determined by iron ac- 

 cording to Berthier's process. As to the precipitate (A), if it 

 contain a notable quantity of vanadium, it is to be redissolved in 

 nitric acid, and to be again precipitated by excess of ammonia, &c. 

 In the opposite case, it is to be fused with one part of silica and 

 three parts of carbonate of soda, and treated with water ; phosphoric 

 acid is to be sought for in the alkaline liquor, and the insoluble re- 

 sidue, composed of silica, alumina, lime, oxide of iron, and zirconia, 

 is to be analysed. 



The mean of several analyses yielded — 



Chloride of lead 9-05 



Oxide of lead 58-31 



Oxide of copper 0'92 



Arsenic acid 11*55 



Phosphoric acid 5*13 



Vanadic acid 1"86 



Lime 7-96 



Alumina, zirconia (?), traces of oxide of iron. . 1*10 



Argil 2-00 



Water 1-12 



99-00 

 The presence of copper in the above-described mineral induced 

 the author to examine whether vanadiate of copper might not be 

 found among the accompanying minerals, this mineral having been 

 stated to exist in Siberia. 



The green earthy portions were first examined, and these were 

 associated with traces of vanadium ; other portions examined did not 

 contain more, and M. Domeiko was about to give up the examina- 

 tion, when he found that the blackish-brown portion which he had 

 taken for ferruginous argillaceous gangue, was much richer in vana- 

 dium than the yellow mineral. 



This substance is amorphous, porous, heavy, of a more or less deep 

 blackish-brown colour, and of a texture which is either compact or 

 earthy ; by the heat of the taper, it melts into a black bead, which 

 is somewhat frothed. By the blowpipe, it gives a green bead, with 

 phosphorus salt, a cupreous globule of lead upon charcoal, and in the 

 matrass it yields a little water. It is rather soft, and its powder is 

 brownish yellow. It lines the cavities of the yellow arsenic -phos- 

 phate mineral, and is frequently associated with the amorphous 

 carbonates of lead and copper. At first sight it is mistaken for hy- 



