51 



Ferric oxide - 96'20 = iron G7'35 percent. 



Lead \SG 



Copper - -18 



Cobalt - - trace. 



Alumina - - '45 



Lime - - '46 



Soda -10 



Phosphoric anhydride - none. 



Arsenic - - trace. 



Sulphuric anhydride - '49 



Sulphur - -16 



Chlorine '03 



Silica - 1-22 



100-15 



No. 6. Purple ore compressed into blocks for use in the 

 blast furnaces (the brick exhibited was made by Messrs. N. 

 Mathieson & Co., of Widnes). 



No. 7. Solution of copper as drawn from the lixiviators, 

 containing, in addition to copper, &c., from three to four grains 

 of silver per gallon, with traces of gold. 



A quantity of potassium (or zinc) iodide sufficient to pre- 

 cipitate the silver present is added to this solution, and the 

 precipitate formed is allowed to subside, the supernatant liquor 

 being passed into vessels in which the copper is precipitated by 

 means of metallic iron. 



No. 8. Precipitate caused by addition of a soluble iodide to 

 solution of copper, &c. (Claude t's process), consisting of silver 

 iodide mixed with various salts of lead chiefly sulphate. 



No. 8A. Silver precipitate, obtained by the reduction of the 

 iodide by means of metallic zinc. 



Silver 



Gold - 



Lead - 



Copper 



Zinc oxide - 



Ferric oxide - 



Lime 



Sulphuric anhydride - 



Insoluble residue 



Oxygen and loss 



100-000 



No. SB. Zinc iodide, obtained by reduction of silver iodide 

 by metallic zinc, and used for the treatment of a further quantity 

 of argentiferous copper solution. 



