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XII. Obfervations on the Magnetic Property of Cobalt and 

 Nickel. Extracted from a Memoir read in the French 

 National biflitute by B. G. Sage, Director of the frjl 

 School of Mines *. 



H 



.AVING refolved to repeat the experiments by which 

 Klaproth, TafTaert, and Haiiy determined that cobalt ind 

 nickel are fufceptible of acquiring magnetic properties, I pro- 

 ceeded to refine thefe femi-metallic fubitances by means 

 which I ihall here defcribe, and by which I extracted from, 

 cobalt the arfenic, iron, bifmuth, and filverj fubflances with 

 which it is almoit always combined. 



Having difengaged the arfenic, by torrefaction, from co- 

 balt ore of a whitiih gray colour, I mixed pounded charcoal 

 with the oxide or brownifh calx which remained in the tell. 

 1 then torrefied it a fecond time, in order to difengage the 

 arfenical acid. 



I then mixed this oxide of cobalt with two parts of vitreous 

 flux f and a little pulverized charcoal. I fufed this mixture, 

 and obtained a button of cobalt, which I au;ain fufed with 

 borax : after thefe two fufions the cobalt exhibited a homo- 

 geneous grain, though it contained iron, bifmuth J, and par- 

 ticularly iilver, in the ratio of nearly a fourth. 



I pulverized this cobalt, and, having mixed it with an 

 equal part of fal-ammoniac, fubjecliea it to diftillation : 

 cauftic volatile alkali was difengaged, and there was after- 

 wards fublimed in the neck of the retort fal-ammoniac co- 

 loured yellow by a little iron. The next fublimated portion 

 had a pale green tint, a colour which arofe from the cobalt. 

 The retort having been kept in a red heat for an hour, fait 

 or muriate of biimuth was fublimated in white foliaceous 

 cryltals. This fait, when put into diftilled water, was de- 

 compofed, and rendered it milky. 



I mixed the muriate of cobalt which remained in the 

 retort with fal-ammoniac, and proceeded to diftillation : the 

 fal-ammoniac, which was fublimated, contained neither iron 

 nor muriate of bifmuth, and was coloured of a delicate green 

 by a little cobalt. 



I fufed the fait or muriate of cobalt which remained in the 

 retort with equal parts of black flux and a fiftieth of pul- 

 verized charcoal : in this alkaline flux I found the cobalt 



• From the journal tk Phji/SfH*, Floreal, an. 10. 

 t Compofed of equal parts of white glais and fixed alkali. 

 + If this metal be in the ratio of a third, it diffufes ttfelf .'.round the 

 button of cobalt, and inciofes it as if it were let in it. 



and 



