NICKEL. 571 



SECTION IV. 



NICKEL. 

 Eq. 369.7 or 29.62. 



This metal resembles iron and cobalt more than any others, 

 and is associated with these metals in meteorites, and in most 

 of the terrestrial minerals which contain it. The principal ore 

 of nickel is arsenical nickel, a mineral having the colour of 

 metallic copper, to which the German miners,, having attempted 

 in vain to extract copper from it, gave the name cupfer-nickel, 

 or false copper. This mineral was discovered, by Cronstedt 

 of Sweden, in 1751, to contain a particular metal, which he 

 called nickel. Nickel imparts a remarkable whiteness to the 

 metallic alloys which contain it, on which account it has come 

 of late to be valued in the arts, being added to brass, to form 

 the well known imitations of silver. 



The metal is prepared from the native arseniuret, or from an 

 artificial arseniuret called speiss, which contains about 54 per 

 cent of nickel, and has been observed by Wohler in octohedrons 

 of a square base, having the composition Ni 3 As. Speiss is a 

 metallic substance which collects at the bottom of the crucibles 

 in which smalt or cobalt blue is prepared. In that operation, a 

 mixture of quartzy sand, potashes, and the roasted ore of cobalt 

 are fused together. The previous roasting never being perfect, 

 a part of the metals escape oxidation, and hence when the mix- 

 ture described is fused, the cobalt, which is more oxidable than 

 nickel and copper, reacts upon the oxides of these metals, and 

 reduces them while it is itself oxidated : the nickel and copper 

 concentrate in the speiss, while the smalt contains almost none 

 of them. A salt of nickel may be obtained by treating speiss 

 in fine powder with an equal weight of sulphuric acid, diluted 

 with four or five times its bulk of water, and adding gradually 

 an equal weight of nitric acid, which occasions the oxidation of 

 both the nickel and arsenic. The green solution thus obtained, 

 when cooled and allowed to stand for twenty-four hours, de- 

 posits much arsenious acid, from which it may be separated by 

 filtration. A quantity of carbonate of potash, equal to half the 

 weight of the speiss, is then added to the solution, which is 



