Natural History. 



435 



soda, to add to the clear solution ammonia, and collect the oxide 

 of iron ; the ammoniacal solution was then heated with potash, 

 so as to drive ofif the ammonia, and the copper thrown down col- 

 lected. By the appropriate tests, lead and arsenic were ascer- 

 tained in the ore, if present. 



Guineveau has analysed the amorphous yellow copper ore. 

 The varieties analysed by Mr. Phillips are the crystallised and 

 the mamellated. The composition of the three kinds are as fol- 

 lows ; 



Sulphur . . 

 Iron . . . 

 Copper 

 Earthy matter 



100. 100. 100. 



The mamellated variety contained no lead. 



A compound of two atoms proto-sulphuret of iron, and four of 

 per-sulphuret of copper, would consist of 



4 atoms sulphur . . . . 64, or . . . 34.78 



2 iron 56, — . . . 30.44 



1 copper . . . . 64," . . . 34.78 



100 



If, Mr. Phillips observes, the lead arsenic and earthy matter be 

 neglected, and its place be supplied by copper, then the com- 

 position of the crystalline variety will approach nearly to, and 

 that of the mamellated variety be almost exactly, that of the ato- 

 mic composition. — Ann. Phil, iii., 301. 



2. Native Carbonates of Manga7iese.— The cuThonnte of manga- 

 nese of Nagiac contains, according to M. Berthier, 



Quartz 210 



Protoxide of manganese . . .443 



Lime 043 



Carbonic acid 304 



Or, removing the quarts, 



Protoxide manganese 



Lime 



Carbonic acid . . . 



1.000 



.560, or Carb. manganese 

 .054 Carb. lime 

 .386 



1. 000 



905 

 095 



1.000 



