OF ARKANSAS. J5J 



No. 5. Brownish-white, cellular araithsonite. 



Composition, dried at 250 clog. F: 



Silica 0.501 



Oxide of zinc Gl .753 



Peroxide of iron 0.552 



Alumina 0.097 



Lime 1.338 



Magnesia trace. 



Carbonic acid, water, and loss 35.759 



100.000 

 The air-dried ore lost 0.14 per cent, of moisture at 250 deg. F. 

 61.753 per cent, of oxide of zinc are equal to 49.59 per cent of metallic 

 zinc. 



No. G. Same as No. 5; different specimen. 



Composition of air-dried ore: 



Carbonic acid and water 35.911 



Insoluble residue (silica, iron, lime, etc.,)- • • • G.839 



Oxide of zinc 57.250 



100.000 



No. 7. Same as No. 5; different specimen. 



Composition of air-dried ore: 



Carbonic acid and water 35.267 



Insoluble residue (silica, iron, lime, etc,.)- • • • 8.298 



Oxide of zinc 56.445 



fcoo.ooo 



The mean of analyses Nos. 6 and 7, shows 56.847 per cent, of oxide 

 of zinc, combined with carbonic acid or water, which is equal to 45.65 per 

 cent, of metallic zinc. In both cases, the residue from the treatment with 

 ammonia, was found to contain zinc, whence the presence of a small 

 quantity of silicate of zinc may be inferred. 



B— ORES OF ZINC FROM MARION COUNTY. 



In this county, the only locality from which specimens of ores of zinc 

 were obtained, is known as " Wood"s mine,'' situated, section 13, township 

 19 north, range 17 west, on the west branch of George creek. The ore 

 occurs here, as in Lawrence county, in pockets or veins in dolomite (the 

 analysis of which is given in No. 34,) and is in most cases found imbedded 



