160 ARTHUE DIESELD ;RFF. 



On N. S. WALES COPPER ORES CONTAINING IODINE. 



By Arthur Dieseldorff, m.e., Freiberg, Baden, Germany. 



(Communicated by A. J. Bensusan, Assoc, r.s.m., f.c.s.) 



[Received Oct. 30. Read before the Royal Society o/N. 8. Wales, Dec. 6, 1899.'] 



Last year Dr. W. Autenrieth of the Chemical Laboratory of the 

 local University, found in a sample of cuprite from Cobar 0*14 

 per cent, of iodine ; this specimen had been collected previously 

 by the writer, and a fresh collection of N. S. Wales copper ores 

 was sought. Samples were sent by Mr. W. B. Yates of Sydney, 

 from thirteen different localities, each one was tested, and seven 

 contained iodine. 



The analysis was made as follows : — Five or six grammes were 

 fused in a platinum or nickel crucible with twenty to twenty-five 

 grammes of chemically pure caustic soda, the mass extracted with 

 water and filtered, five to ten grammos of chloroform added, the 

 vessel cooled, and a few drops of nitrite of sodium added (NaN0 2 ) 

 solution acidified with sulphuric acid cooling it all the time. The 

 iodine becoming free is absorbed by the chloroform, colouring it a 

 reddish-pink. 



In colorimetric analysis by comparison with standard solutions 

 gauged from 01 per cent, down to - 001 per cent., the percentage 

 of iodine taken up by the chloroform can be found. The standard 

 solutions are prepared from iodide of sodium. In the above 

 manner the following percentages of iodine were found, and the 

 samples also assayed for silver : — 

 No. 0. Cuprite with malachite in the cavities of the 



former, being the original specimen £*£&, J^Zlt. 



collected by the author in N. S. Wales 0-13 0-002 

 No. 1. Ore from British Broken Hill Mine, mixture 



of chrysocolla, cerusite cuprite, quartz 0'022 0028 



