1851.] Report on the Copper ores of the Deoghur Mines. 9 



There is no trace of antimony in this mineral, and it thus forms a 

 distinct lead Fahlerz ! which I do not find any where described ; the 

 latest authority, Nicol (p. 490), appears to think lead an accidental 

 occurrence. Before the blow-pipe in an open tube it blackens and 

 gives an acid water, but no sublimate. On charcoal it gives no fumes 

 nor any deposit but is converted without ebullition into a black cindery 

 slag which with soda gives a pale metallic copper mixed with lead. If 

 the heat is long continued the lead of course disappears and the copper 

 alone remains. 



This ore was one of those of which I could collect enough for an 

 amalgamation by the Mexican process, and as will be seen in the sequel 

 it gave a very good product. 



E. 

 Bright Grey Copper. 

 This is a grey copper, a Fahlerz with some lead but no silver. It is 

 massive, with a steel-grained fracture, and brittle, but the latter por- 

 tions are hard to pound ; with green and yellow marblings and stains, 

 it passes into a green and yellow earthy gossan. 



3rd Group, Red Ores. 

 F. 

 Bright, brick-red Pacos, or Color ados. 

 This ore exactly resembles the museum specimens of Peruvian Pacos 

 from my own collections, that is, an earthy iron ore. I collected a suffi- 

 ciency of this ore to subject a pound troy of it to a proper Mexican 

 amalgamation process, of which the results will be described in Part III. 

 The composition of an average lot taken from that used for amalga- 

 mation was as follows : — 



Water, sulphur and carbonic acid,* 14.30 



Silver, 0.21 



Iron, peroxide, 15.40 



Copper, peroxide, 27.20=21. 8 copper. 



Sulphur, 10.45 



Earthy silicates, 32.45 



100.01 

 It is thus a tile copper ore, with a minute portion of silver. 



* Some of the Copper appears to be in the state of Carbonate. 



C 



