l 264< NEW METAL NICKELINE. 



the acids with a flrong eftervefcence. I remember to have 

 had, fome years ago, this precipitate of a bad colour, and 

 not then to have examined it, considering it as a mixture of 

 iron ; nickel, and arfenic, (which lad continually made itfelf 

 noticed by its odour of garlic) : But at laft I fufpecled its 



I i nature. 



bv caufticpot- If the folution of nickeline is decompofed by eauftic potafh, 

 ' it gives a precipitate which refembles in its colour carbonate 



of chrome j that is to fay, it is of a deep greenifli-blue, which 

 does not change when it is warned : being dried with a gentle 

 heat, it aftumes a pale colour, which becomes deeper when it 

 is moiitened with v* iter. 



by ammonia* If any of the foregoing folutions of nickeline is mixed with 



ammonia to excefs, the liquor alTumes a pomegranate red co- 

 lour, and remains transparent ; which proves that it does not 

 contain any iron, beaufe that this latter is not foluble in 

 ammonia. By candle-light this folution is with difficulty dif- 

 tinguifhed from that of perfectly pure nickel ; but by day- 

 light, this latter is of an amethyft red colour, as I have elfe- 

 where remarked. 



Points of com- I (hall now compare the principal properties in which nic- 



f* 3 keline refembles altogether, or in part, nickel or cobalt, and 

 nickeline and » ' * ' 



nickel or cobalt, thofe in which it is diftinct from them. 



It refembles cobalt — 

 Rcfcmbhnces of '- By * ts property of fuper-faturating itfelf with oxigen at 

 nickeiine and the expence of the nitric acid, and thus forming a body which 

 refembles the black oxide of manganefe with regard to its 

 folubility in the acids: 2. By its property of not being re- 

 ducible but by the intervention of a combuitible body. 

 It differs from cobalt — 

 Differences be- 1. By the blackifli-green colour of its folutions, even when 

 and e 'coba^ elmC the y are emire,v neutralized. It is known that the neutral 

 folutions of cobalt in the fulphuric, nitric, and muriatic acids, 

 are of a crimfon-red colour; and that the muriate of cobalt 

 alone becomes of a greenifli-blue on being deprived of its 

 water : from whence it happens that an excefs of acid pro- 

 duces this colour, becaufe it combines with the water : With 

 the muriate of nickeline precifely the reverfe takes place; 

 when m xed with water it is green (although of a lefs beau- 

 tiful coJbuY than the cobalt without water), and when de- 

 prived of its water it becornes reddifh. — 2. By the colour of 



its 



