510 W. H. Melville — Josejrfiinite, a neio Nickel-Iron. 



The pebbles are strongly magnetic 



Analyses. — The analyses were conducted with the aim of 

 separating the pebbles into their proximate principles and also 

 their ultimate constituents. Two different lots of about twelve 

 grams each were pulverized in a steel mortar, a delicate and 

 tedious operation owing to the extreme malleability of the 

 nickel-iron. Two complete analyses of these samples were 

 made. The ratio between the nickel and iron in the metallic 

 state was ascertained by deducting from the total amounts of 

 each of these elements those quantities which were found in 

 other combinations. The ordinary method of fusion with 

 sodium hydrate and subsequent treatment of the residue with 

 concentrated nitric acid failed to give the true contents of the 

 metallic portion in the pebbles, because the nickel-iron was not 

 passive in this acid. The ratio between the nickel and iron, 

 however, could be obtained by this method. 



The stony matter was freed as far as practicable from the 

 magnetic parts by a fractional process, that is to say by the 

 repeated use of - an electro-magnet and by the decantation of 

 the light particles suspended in water. The siliceous portion 

 was then analyzed. A fresh sample was treated with diluted 

 hydrochloric acid, and after repeated evaporations the soluble 

 silica was separated from the insoluble residue and weighed: 

 The insoluble residue was analyzed, and the percentage com- 

 position of soluble silicate was inferred from this analysis, the 

 analysis of the total siliceous matter, and the total silica of the 

 pebbles. 



The mean composition of the pebbles is shown by the fol- 

 lowing numbers : 



Per cent. Per cent. 



Nickel free, Ni 60-45 Nickel combined 0'25 



Cobalt, Co 0-55 



Iron free, Fe 23-22 Irou combined 1'19 



Pyrrhotite, Fe 7 S s 0-55 Sulphur 0'22 



Chromite, FeO . CrO, ) nin ri ■„ A n^ 



hi i-i PA u A f 0:12 Chromium. 0-04 



Magnetite, FeO . Fe„0„ \ 



Copper, Cu 50 



Arsenic, As 0-23 



Chlorine, CI 0-04 



Silicate (anhydrous) 12-26 



H o below 100° C. 0-81 



H 2 above 100° C. 1-12 



C0 2 . trace 



Volatile matter 0*70 



100-55 



