The regulus, when depurated, has a ſpecific gravity of 9,000, or more; but the common regulus, obtained by the firſt reduction, little exceeds 7,000. Aqua regia, and nitrous acid, diſſolve it perfectly; muriatic acid, ſlowly; vitriolic acid, not without boiling almoſt to dryneſs and the acetous acid does not act upon it, unleſs in a calciform ſtate. The quantity of phlogiſton ſeparated by ſolution, may be called 156; and this it retains with a force about equal to that with which iron retains its phlogiſton (§ 197).
The heat neceſſary to melt it, is about equal to that which gold requires; but when depurated, it is almoſt as difficult to melt as iron.
The properties of it are more fully examined elſewhere[[72]].
NICCOLUM nativum (nickel) native, united to iron and arſenic. Native.
It ſometimes, perhaps, contains cobalt. As it contains neither ſulphur nor mineralizing acid, and is perfectly in its metallic form, it muſt be called native, although joined to other metals.
NICCOLUM aeratum (nickel) mineralized by aerial acid. Aerated.
Cronstedt Min. § 255.