1854.] Notes on the Iron Ore of Korana. 93 



In powder it does not effervesce with hydrochloric acid, but parti- 

 ally dissolves, the solution acquiring the characteristic brown- 

 yellow colour of perchloride of iron. 



A portion, finely powdered in an agate mortar, was digested in 

 aqua regia, and evaporated to dryness. Water acidulated with aqua 

 regia was then added, and the solution separated by filtration from a 

 small insoluble residue of a dark-brown colour, apparently unde- 

 composed ore (A). 



To the filtered solution ammonia in slight excess was added, which 

 caused a copious precipitate of peroxide of iron (B). This was 

 separated by filtration, and the filtered liquid tested in the usual 

 way for lime and magnesia, but without discovering a trace.* Hy- 

 drosulphate of ammonia did not indicate the presence of manganese. 



The precipitate (B) was re-dissolved in an excess of aqua regia, 

 the solution cooled as well as the weather would permit, treated 

 with carbonate of soda and well stirred during effervescence. 



The peroxide of iron precipitated was then separated by filtration 

 and the clear solution boiled with a slight excess of carbonate of 

 soda. No trace of manganese however could be detected. 



The portion of ore (A) insoluble in acid was fused with carbonate 

 of potash in a platinum crucible, and the resulting brownish slag 

 treated with aqua regia. It dissolved entirely, with the exception 

 of a few flakes of silica. The solution was then evaporated to dry- 

 ness, redissolved in acidulated water, filtered to separate silica, and 

 from the clear solution I precipitated the remaining peroxide of iron 

 in the usual way, testing the solution filtered from it for lime and 

 magnesia without detecting any. 



From the above it is evident that the only constituents of the 

 ore are — 



"Water. 



t Peroxide of iron. 

 Silica. 



* In the specimen analyzed by Mr. Piddington he found 65.14 per cent, of 

 carbonate of lime (limestone). 



f Not having any caustic potash nor material for preparing it available, I was 

 unable to ascertain if any alumina occurred in the ore. From the appearance of 

 the precipitated peroxide of iron, we should say it is absent or nearly so. 



