﻿182 



Canadian Record of Science. 



produced by reduction of salt-cake with coal. The sodium 

 sulphide forms with the matte an exceedingly fluid 

 magma, from which, on cooling nickel separates as a 

 " bottom" or cake of nickel sulphide occupying the lower 

 part of the matte pot, while copper floats upward with the 

 soda sulphide. After cooling a sharp demarcation line is 

 Fig. 4. found between the 



two sulphides, and 

 separating the " bot- 

 toms' or crude sul- 

 phide of nickel and 

 repeatedly resmelt- 

 ing with sodium sul- 

 phide the copper can 

 be almost entirely 

 removed and pure 

 sulphide of nickel 

 can be produced. 

 We are thus justified 

 in drawing the fol- 

 lowing inference. 



If copper-nickel - 

 iron sulphides can 

 be held in a molten 

 condition either by 

 using prolonged heat 

 or by imparting 

 fluidity by the addi- 

 tion of Huxes for a 

 sufficient period of time to allow the mutual repulsion of 

 the metals to act, the copper and nickel will separate 

 as individual minerals, the sharpness of separation being' 

 dependent on the fluidity of the mass and the time 

 occupied in cooling. 



^0^ 



m 

 m 



n% 



21% 



Central vertical line of matte. 



Vertical column = per cent. Horizontal column dis- 

 tance from top of pot. 



