1 3 2 Rsgulus of Nickel [Book- VI. 



a blue folution -with volatile alkali, and in nitrous acid 

 its folution is of a full green. 



From its magnetic property, nickel has been con- 

 fidered as a modification of iron ; and by its producing 

 a blue colour with volatile alkali, it has been fup- 

 pofed to be an alloy of copper with various metallic 

 fubftances. Chemifts, however, are now very gene- 

 rally agreed in confidering nickel as a diftinct metallic 

 fubftance. 



M. Sage affirms, that when four parts of oil of vitriol 

 are diftilled with one part of the regulus of nickel irt 

 powder, the fulphureous acid paries over; the refidue 

 is greyim, and, being diffolved in diftilled water, pro- 

 duces the mofl beautiful green colour. The cryftals 

 obtained from this folution are foliated, and of the 

 colour of an emerald. According to M. Arvidfon, the 

 vitriolic acid forms a green fait, in decahedral cryftals, 

 with the calx of nickel. 



This calx is eafily foluble in the nitrous acidj and 

 cryftallizes in rhombic cubes. According to M. Sage, 

 all the other folutions of nickel, or its calx, either 

 in the muriatic acid or in vegetable acids, are more 

 or lefs green. It has been faid, that the nickel con- 

 tained in cobalt occafions the fubftance known under 

 that name to produce a green colour with acids. 

 Nickel differs from cobalt in not being iepa rated from 

 acids by the addition of any other metal. 



Nickel detonates * with nitre ; this detonation af- 

 forded M. Arvidfon a method of difcovering the 

 prefence of cobalt, which no other proof has rendered 

 fenfible. Nitre has likewife the property of augment- 

 ing the intenfity of the hyacinthine colour, commu- 

 nicated to glafs by the calx of nickel. The calx of 



Inflames, and explodes fuddenly. 



nickel, 



