190 Mr, Field, [Feb. 3, 



WEEKLY EVENING MEETING, 



Friday, February 3, 1860. 



Rev. John Barlow, M.A. F.R.S. Vice-President and Secretary, 



in the Chair. 



Frederick Field, Esq. F.R.S.E. 

 On the Mineral Treasures of the Andes, 



Owing to the great extent of country, the difficulty of access in many 

 parts, and the comparatively few labourers in the field of science, 

 much of the mineralogy of the district, bounded on the east by. the 

 Cordilleras, and on the west by the Pacific Ocean, remains to be in- 

 vestigated. 



European enterprise and capital have, however, incidentally effected 

 much. The miner, finding a ready purchaser in the smelter or mer- 

 chant for his ores and other mineral productions, traverses the hills 

 and mountains in quest of the treasures his country supplies, bringing 

 them into the various ports on the coast for sale. It necessarily 

 happens that he meets occasionially with some minerals of which he is 

 not cognizant ; but from their high specific gravity, metallic lustre, or 

 other physical appearances, he deems them to be not wholly destitute of 

 value. Thus, oftentimes, independent of purely scientific research, 

 many curious natural compounds are brought to light, which other- 

 wise perhaps might have lain for ages hidden in the deep recesses of 

 the hills. 



The chief wealth of the Andes, in a monetary point of view, consists 

 of copper and silver minerals. Gold, although extensively dissemi- 

 nated, never occurs in very large quantities in one particular spot. The 

 copper and silver mines on the contrary, yield those metals in very 

 great abundance. 



The copper ores maybe divided as follows: — 1. Those minerals 

 which consist of native copper, in a nearly pure condition, or combina- 

 tions of the metal with oxygen, and the oxides combined with carbonic, 

 silicic, phosphoric, and vanadic acids, as well as with chlorine, in the 

 mineral atacamite. 2. Minerals consisting essentially of copper, iron. 



