Arsenical Nickel

Not having any where met with a Cornish specimen of Arsenical Nickel, I am induced to doubt whether it be ever found in that country, and therefore exhibit a figure of it here. It is by no means a rare mineral on the Continent, having been found plentifully in several parts of Germany, in France, Spain, Sweden, Siberia, and Norway; it is generally accompanied by Arsenical Cobalt, which it often contains in combination, and thus, as Werner suspects, it may sometimes pass into Grey Cobalt. Haüy observes that the colour, together with the dull rather rough surface of the fracture, offers a character that hitherto appears to be peculiar to this substance, whence he considers it as one of those minerals that may be most easily recognized when they arc met with a second time. I have endeavoured to give this peculiar appearance to the figure, and hope I have not altogether failed. The colour, if I may be allowed the expression, is a pale yellow grey, to which a warm glow is added by a considerable admixture of red^*. Lustre metallic. Fracture between splintery and conchoidal, with a finely granulated surface; it is brittle, but requires a smart blow to break it. Mr. Sage found in 100 parts,

• 75 Nickel,
• 22 Arsenic,
•   2 Sulphur;

from which analysis I suppose his specimen to have been very pure, as Bergman had found Iron and Cobalt besides. It is the ore from which Nickel is obtained for use: specimens of it are often found decorated by the green oxyde produced by its decomposition. Natural crystals have not been found, but artificial crystals are described by the Count de Bournon.