Analysis of Arsenical Nickel. 295 



the space will allow of? Tliey should be calculated to bear the 

 greatest possible load, with safety. My experiments furnish the 

 necessary data as far as regards the strength of the stone. They 

 also show which stone is best adapted for the purpose. The 

 Dundee stone is decidedly the strongest of the specimens I have 

 tried. I am, sir, yours, &c. 



Oct. 17, 1820. Thortas Treugold. 



2, Grove Terrace, Lisson Grove. 



XLV. Analysis of Anenicai Nickel, and the Arseniate of Nickel 

 ofAllemont ( Deparlmenl of the here) . By M. Beuthier*. 



1 H E arsenical nickel of Allemont has not hitherto been com- 

 pletely analysed. Its colour is reddish brown, approaching that 

 of copper, but paler ; it has a metallic lustre both in pieces and 

 in powder ; its fracture even, or covered with small asperities, 

 and a little shining ; it Joon tarnishes in the air ; it is bridle, and 

 easily reduced to powder :— specific gravity 7'29. It emits a 

 garlic smell when struck with steel ; before the blow-pipe it gives 

 a dense arsenical smoke ; melts readily a little above a red heat. 

 Heated for an hour at 150" of Wedgwood, in a crucible lined 

 with charcoal, it loses only about 0- 12 to 015 of its weight, and 

 does not change its appearance. This loss appears to be almost 

 entirely arsenic. 



This mineral consists principally of arsenieuret of nickel, but 

 contains also a small (juantity of arsenieuret of cobalt and sul- 

 phuret of antimony. It was analysed in the manner following: 



To the mineral was added nitric acid at intervals; and it 

 was boiled during two days, which dissolved the whole. The 

 arsenic and sulphur were acidified, and the nickel, cobalt and 

 antimony oxidated. Water being added to the solution, a white 

 powder fell down, weighing when dry 0'?7fi parts, which was 

 proved to consist almost entirely of arseniate of antimony, by 

 the following experiments : It was first heated in a silver crucible, 

 with four times its weight of caustic potash ; and then treated 

 with boiling water, which dissolved all but a small residue of 

 oxide of nickel, weighing 0*008, arising from a small portion of 

 arseniate of nickel which had fallen down along with the ar- 

 seniate of antimony. The above-mentioned solution in boiling 

 water was then boiled with nitric acid, which produced a white 

 sediment, composed of oxide of antimony and arsenic acid, 

 weighing 016 parts. Its component parts were separated by 

 solution in muriatic acid, slow evaporation to dryness, and sub- 

 sequent addition of water, which caused a copious deposit of in- 



• From the Journ. ilas Miitcx, iv. 4G7. 



soluble 



