British Mineralogy. 179 



Sulphur . . 



49-32 



Iron .... 



45-73 



Nickel . . . 



1-99 



Cobalt . . . 



1-24 



Copper . . . 



1-18 



Insoluble . . . 



0-06 



99-52 



A comparison of the results of this analysis of the globules of 

 iron pyrites with those of the nickeliferous pyrrhotine in which 

 they occur imbedded is very interesting. They contain nearly 

 the whole of the cobalt and copper present in the ore, along with 

 a little of the nickel, and would appear to have segregated out 

 of the general mass, carrying with them the copper and cobalt. 

 In the case of the Craigmuir nickeliferous pyrrhotine, where 

 these segregations do not occur, the cobalt is found still remain- 

 ing with the nickel in the ore. 



A curious metallurgical incident may tend to throw some 

 light on this subject. Some years back, at a smelting- works in 

 Norway engaged in producing nickel regulus (a sulphide of iron 

 and nickel with a little copper), a considerable quantity of the 

 regulus broke through the clay bottom of a furnace and remained 

 in a thick sheet of, say, some six inches in depth interbedded be- 

 tween the foundation and the bottom of the furnace; at the same 

 time, whilst it was protected from oxidation by the latter, it had 

 no doubt remained some months at a temperature much below 

 fusion, and probably had been at no time higher than a red heat. 

 Upon breaking up the bottom to reline the furnace, it was found 

 that this mass of regulus had undergone a very remarkable 

 change; for instead of being a homogeneous and uniform mass 

 of one character as originally, it had now in great part been con- 

 verted into a mass of small round spherical concretions, varying 

 in diameter from y 1 ^ to J an inch, almost resembling an oolitic 

 limestone in structure, and which had evidently been formed by a 

 species of segregation or molecular movement in the solid mass of 

 regulus. A chemical examination has not as yet been made, but 

 is likely to afford interesting results. 



The segregation of these spherules of sulphide of iron seems 

 to have carried the cobalt contained in the mineral along with 

 them ; for it was only with some difficulty that a trace of cobalt 

 could be detected in the pyrrhotine in which they were imbedded ; 

 and it is curious that there appears to be a tendency for cobalt 

 to associate itself with the bisulphide of iron (pyrites), whilst 

 nickel appears to prefer uniting itself with the magnetic sulphide 

 (pyrrhotine). 



A chemical examination of several hundred specimens of iron 



N2 



