354 
APPENDIX. 
they pursue, and which has such a close analogy with that called 
the Catalonian. For there is every reason to believe that this pro- 
cess is applicable to none but very rich ores, and such whose bed or 
matrix is essentially siliceous ; but it is probable, that experience has 
taught the Negroes to make a suitable selection, and, perhaps, they 
are even acquainted with the use of quartz as a flux. It would have 
been curious and highly instructive to analyse the scoria produced 
by their furnaces ; but unfortunately none could be procured. 
V 
