8— COMPLEX ORES. 

 By Duncan Simpson, F.C.S. * 



[Abstract.] 



Deals with composition and varieties of complex ores carrying^ 

 noble and base metals. Gives geographical distribution of some of 

 the best known ores. Discusses methods adopted in various districts 

 for the treatment of such ores, and the recovery of the contained 

 metals. 



Relates experiments recently made by the author in " heap 

 roasting " a copper ore containing silver, nickel, lead, and zinc, at 

 places in Natal and Zululand. 



