THE 



AGllICULTUKAI. MUSEUM. 



OMNIS FERET OMNIA TELLUS. VIRG. 



Vol. 1.] Georgetown, Ca. Oct. 10, 1810. [No. 8 



A new Method of assaying Copper Ores. 

 By Geo. Fordyce, M. D. F. R. S. 



F.rom the Transactions of the Royal Society of 



London. 



Ohservutions on the above Process. 

 [Concluded] 



Ttisjibout twenty years ago that I conirivf-d some 

 methods of assaying ores, which might avoid tedious iind 

 troLibiesome roastings and fusions in great deorees of 

 heat, which require a dextei'ity that is only to be acquir- 

 ed by great practice, and which, after ail, form a process 

 that is often varioiis in the result, and sehiom shews the 

 substances contained in the ore, excepting the metaf. 

 The principles on which these processes depend^ as far 

 as regards copper ores, are, 



First. JMetals are attracted more strongly by acids 

 than by sulphur, with whicli they are often combined in 

 their ore's. In consequence, if a metal be combined 

 with sulphur in an ore, it maybe sepai'atrd by applyino- 

 an acid, which will unite with the metal, and separate 

 the sulphur. The metal may generally be separated 

 from the acid, in its metallic form, by means of another 

 metal which attracts the acid more strongly. 



Secondly. Arsenic unites with vitriolic, nitrous, and 

 muriatic acids, forming a coirosion or compound not 

 soluble in water ; whereas, niost other metals may be 

 united with one of these acids, or a mixture of them, so 

 as to form a cGmpoLind soluble in water" therefore, if 



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