PURIFICATION OF NICKEL. gj 



lovir, and a gelatinous consistence. It is a Uue StarVey's 

 soap. Wheu i poured freith oil of turpentine on this soap 

 to dilute it, and exposed it to the action of heat, there was 

 a considerable extrication of gas, and the globules perceji- 

 tibly tiiminished. This was owing to the hidrogen, which 

 the soda had absorbed during the galvanic action, being 

 separated again. When these small globules were takeu 

 out, and dried on paper, they changed their nature in a 

 few seconds, and nothing was found but small heaps of 

 soda. 



IX. 



On the Purification of Nickel bu Means of Sulphuretted lU- 

 drogen: b?/ Mr, Robiquet, Apothecary*, 



JLaAVING treated a considerable qnnntity of speiss in the Attempttoob- 

 laboratory of Mr. Vauquelin, with a view to estracT: from it ^'f'} t^"''«^*'<^^- 

 pure nickel, this process afforded me an opportunity of pickel. 

 making some remarks, which I have thought necessary to 

 make public, that they who eng^ige in a similar pursuit may 

 avoid the same errours. I shall give a brief account of the 

 process I followed. 



I took two pound;; of speiss, which I treated directly Treated with 

 with nitric acid diluted with two parts of water. I omitted "'-^'j't^.' \^\ 

 the roasting common!}' directed, from the danger of so large ous ruastinj. 

 a quantity of aisenical vapour, and because the roasted ore 

 is not acted upon so easily by acids. Thus the solution, 

 which took place very quickly, was accompanied as usual 

 wlih an evolution of nitrous gas; and the sulphur separated 

 in proportion as it went on in a flocculent precipitate, which 

 afterward united into a mass. The whole of the acid, at 

 32° employed successively was 61bs. 8oz. ; and the resi- 

 duum, which proijably contained a pretty large quantity of 

 arseniate of iron, weighed 7 oz. C drachms. I iiiteved the Arsenutes of 

 liquor, which 1 diluted with a large quantity of wafer j^, '^"'^ ^^'^^ <=''*»»!t 



* Anriales <le Chiniie, vol.LXlX, p. 28J. 



order 



