i88: 



27 



Trans. N. Y. Ac. Set, 



under a powerful magnifying glass, from the residue, by using a fine 

 wire with a small hook at the end. 

 The result of the separation was : 



A. B. 



Franklinite 48.2 per cent 44,7 per cent. 



Red Oxide 2.7 " 7.4 



Silicates & Carbonates 49.1 " 47.9 " 



1 00.0 1 00.0 



The next method adopted was to take average samples of the Frank- 

 linite ore, carefully separate from a portion of the sample the mineral 

 constituents contained in the same, and analyze the separated miner- 

 als. Several analyses of average samples were then made, and from 

 these, and the analysis of the separated minerals, the mineralogical 

 constitution of the ores was calculated. 



The complete analyses of the average samples were as follows : 



The analysis of the constituent minerals gave the following figures, 

 as representati\-e of their constitution, after separating and cleaning 

 them from adhering gangue, etc., under a magnifying glass : 



Silica, and insoluble matter 



Oxide of zinc 



Proto-sequi-oxide of iron.. . 



Alumina 



Protoxide of manganese... 



Lime 



Magnesia 



Carbonic acid 



Copper 



A . Franklinite. 



2.62 



21.60 



55.80 



trace. 



17. c6 



1.28 



0.30 



1-35 

 none. 



100.04 



B. Zincite. 



0.81 



95.23 

 trace, 

 trace. 



3.51 

 0.32 

 o. 10 



0.37 

 undetermined, 



100.34 



C. IViUemite 

 Residue. 



24.36 



48.06 



1.97 



12.25 

 6.29 

 0.99 

 6.28 



trace. 



