420 PR0CEEDIN08 OF THE NATIONAL MUSEUM. vol.52. 



rial interspersed with the usual metallic iron and abundant iron sul- 

 phide. The silicate minerals are olivine and pyroxenes of both the 

 normal orthorhombic and twinned monoclinic types. No feldspars 

 are present. Oxidation has badly obscured the finer details of struc- 

 ture and rendered impossible the identification of any minor constit- 

 uents which might perhaps exist. The pulverized material boiled in 

 water for half an hour gave a filtrate reacting distinctly for chlorine, 

 calcium, and sulphur, and a portion allowed to stand for a like length 

 of time in one part nitric acid and 20 parts water, gave strong quali- 

 tative reactions for PgOj, CaO, and FcjOg. A complete analysis by 

 Dr. J. E. Whitfield yielded: 



Per cent- 

 Metal 6.22 



Metallic sulphide 9. 57 



Silicates 84.21 



Total 100. 00 



The metallic portion yielded: 



Iron 90.63 



Nickel • 8-85 



Cobalt 38 



Phosphorus 14 



Total 100.00 



The silicate portion yielded : 



Silica (SiO,) 41.45 



Ferric oxide (Fe^Os) 3. 46 



Chromic oxide (Cr.Os) 40 



Alumina (AUOg) 3. 17 



Ferrous oxide (FeO) 17. 77 



Manganous oxide (MnO) 21 



Lime (CaO) 1-68 



Magnesia (MgO) 28.99 



Nickel oxide (NiO) 91 



Cobalt oxide (CoO) 04 



SodaCNa^O) 90 



Potash (K2O) -14 



Total 99.12 



A recalculation of these results gives the mass composition of the 

 stone as follows : 

 Metallic portion: 



Iron(Fe) 5.64 



Nickel (Ni) 55 



Cobalt (Co) 02 



Phosphorus (P) 01 



Troilite: 



Iron (Fe) 6. 09 



Sulphur (S) 3.48 



