184 



Mr. J. Napier on Copper Smelting, 



Insoluble in acids 

 Peroxide of iron 

 Oxide of copper 

 Sulphur . . 

 Sulphuric acid . 

 Lime .... 

 Arsenic, tin, antimony, &c 



50-4 

 7-8 

 5-4 

 2-3 

 5-4 

 11-7 

 16-7 



997 



Matter taken from the flue of a calciner used for powder close 

 to the furnace before it entered the culvert, and where the de- 

 posit was greatest ; this was in the form of a powder, and having 

 been exposed had absorbed moisture. 



Insoluble in acid . . . 4*0 



Oxide of copper . . . 24*5 



Protoxide of iron . ' . . 22*5 



Sulphuric acid .... 32'6 



Soda 2-3 



Lime '3 



Water 13-0 



Antimoay and arsenic . . '6 



99-8 



Some of the copper and iron were as sulphates. The next is 

 from the culvert leading from the same powder calciner as the 

 flue from which the samples last taken led from ; taken about 

 28 feet from the furnace. 



99-5 



The difference between this and that deposited in the flue of 

 the same furnace is worthy of remark. In the former there is 

 much sulphate of copper and iron, and but little of the more 

 volatile matters ; while in this last, taken at a greater distance 

 from the furnace, where the heat is less, the more volatile mat- 

 ters are in greater quantity. 



[To be continued.] 



