10 Report on the Copper ores of the Deoghur Mines. [No. 8. 



G. 



A dull, pale red, and liver-coloured Pacos. 

 This ore also contains silver, and two small nodular specimens of a 

 dark earthy liver-coloured aspect, seem richer than the rest, but I have 

 as yet only these two bits, and indeed not much of any of this kind. 



H. 



Dark hard veins of a red tile-copper ore, with black shining specks 

 and veins of protoxide of iron. This ore contains some silver but we 

 have but very little of it, and I can only roughly estimate it by a guess 

 at about two-thirds the value of F. 



5th Group, Galenas. 



J. 



Bright large-grained Galena, no silver* 



K. 



Cupro-Plumbite (Breithaupt) . 



This is another Peruvian ore which we have unexpectedly found. It 

 may be described as massive, in very thin veins, forming alternate streaks 

 of a bright and dull, dark, blue-grey, galena-like mineral ; the streaks 

 lying diagonally across the small veins ; sometimes in larger glancing 

 masses, and at others in thin needle-like streaks. I have not found any 

 silver in it, though Breithaupt gives it 0.5 per cent. Before the blow- 

 pipe, in the open tube, it fuses and gives acid fumes. 



On charcoal it melts, swells up, and boils, sending out a rapid stream 

 of dull sparks if brought too near the reducing flame. Finally it gives 

 a globule of lead which contains copper but no silver. 



Our specimens are all in such very thin veins that a quantitative 

 analysis would always give uncertain results, owing to the matrix. I 

 have therefore preferred to wait till we obtain larger masses with some 

 new supply. 



Part III. — Amalgamation assays. 



I thought it of much importance that we should ascertain if, with 

 the high temperature and great moisture prevailing here during most 

 part of the year, the Mexican amalgamation process could be success- 

 fully used for the extraction of the minute portions of silver which 



