52 F. Field on a new Mineral. 
without the intermission of an hour, was passed in the search 
after truths the most important, and at whose hands the human | 
Newton's. Yet in sen the statue which preserves his like 
and sublime. | 
Art. IX.—Description of a new Mineral Species from Chili; ¥. “ | 
FREDERICK Fietp. (From a letter to J. D. DANA, dated | 
Guyacana, Coquimbo, Chili, September 6, 1858). i 
I sEND =~ a specimen of a mineral from the Cordilleras of 
Chili, which appears to me highly interesting. It consists entirely : 
of copper, arsenic and sulphur, having the following composition: — 
“ : “ - : ‘50 a 
Copper, - 
Sulphur, - - . - - 31-82 
Arseni - - - - : +? ae’ 
Tron, silver, - he - = traces. 
and consequently has the following formula: 3Cu,S+AsSs 
and may be considered as a tribasic sulpharseniate of coppeh — 
like the artificial tribasic sulpharseniate of potassium, in W. : ch 
proposed the name “ Gwayacanite” for this new species, a5 @- 
mineral was first brought to the large copper nk 28 works & 
