242 On the Deutarseniurei of NickeL 



m 



Before the blow-pipe, in a tube, as well as upon cliarcoal, it indi- 

 cates the presence of large quantities of arsenic, and fuses to a brit- 

 tle metallic bead. If the bead be roasted and fused with borax, it 

 gives a blue glass. By breaking the glass, and fusing the metallic 

 bead contained in it with phosphoric salt, the action of nickel may 

 be observed, viz. a reddish brown transparent glass in the exterior, 

 and a brown opake glass in the interior flame. If an insufficient quan- 

 tity of borax was employed, the phosphoric salt gives indeed a blue 

 glass and it is therefore necessary to repeat the operation with borax. 

 The purest pieces of the mineral were set apart for analysis, and 

 0.8028 grammes, powdered and ignited with ten times its weight of 

 a mixture of equal parts of saltpeter and carbonate of soda, in a pla- 

 tinum crucible. The fused mass was treated with water and filtered; 

 the remainder on the filter was dried and the filter itself burned, then 

 dissolved in hydrochloric acid and heated with sulphuric acid. The 

 sulphate of baryta, which was thus precipitated, resulted from the heavy 

 spar, with which the mineral was so penetrated, that it could scarcely 

 be detected by the eye. The weight of the precipitate was 0.061 1 

 grammes and therefore that of the pure mineral 0.7417 grammes. 



To the solution, from which the baryta was precipitated, muriate 

 of ammonia was added in considerable quantity, and then ammonia 

 in small excess, by which oxide of iron was thrown down, and its 

 weight determined to be 0.0348 grm. 



Nickel and cobalt were then separated according to the method 

 of Laugier, as that of Philips failed after repeated trials. The ox- 

 ide of nickel, thus obtained, weighed 0.1954 grm., a part of which 

 reduced with hydrogen, gave for the whole quantity of metallic 

 nickel 0.1538. The oxalate of cobalt ignited for a moment gave 

 0.025 for the metal. The arsenic was determined in this analysis 

 by loss, since in another, in which the mineral was dissolved m ni- 

 tric acid and precipitated by sulphuretted hydrogen, the quantity 

 arsenic was found to correspond. 



According to the above analysis, the arseniuret of nickel from 



Riechelsdorf consists of 



m 



in 0.7417 grammes, or, in 100 parts, 



Nickel, - - 0.1538 - - 20.74 



Cobalt, - - 0.0250 - - 3.37 



Iron, - - 0.0241 ' - - 3.25 



Arsenic, - - 0.5388 - - "72.64 



0.7417 100.00 



of 



