2,68 Elements of Mineralogy. 



pitated then by the Prujfian alkali ; the pre- 

 cipitate calcined isre-diffolvedin nitrous acid, 

 and the folution evaporated to drynefs ; the 

 iron being thus deplogifticated becomes info- 

 luble in nitrous acid ; the calx of zinc is re- 

 diffolved in that acid, and again precipitated 

 by the PruJJian alkali. 100 gr. of that pre-* 

 cipitate wafhed and dried are equivalent to 20 

 of zinc in its metallic ftate, and 100 gr. of 

 dephlogifticated iron are equivalent to 73,5 

 of iron in its metallic ftate. 



SPECIES IX. 



Argillaceous^ Sbiflofe^ or jlaty Copper Ore* 

 Kupfer Schiefer. 



32. This ore feems to confift of the vi- 

 treous copper ore, intimately combined with 

 fhiftus, and not barely difperfed through it; 

 in vifible particles ; it is of a brown or black 

 colour, lamellar texture, and very heavy ; it 

 affords from 6 to 10 per cent, of copper, and 

 is of difficult fufion, unlefs lime-ftone be 

 added ; it contains a little bitumen, calcareous 

 earth and iron, asjhi/tido. 



SPECIES X. 

 Bituminous Copper Ore. Kupfer brand ertz. 



33. This is faid to be found in Sweden -, it 

 i* a fpecies of coal which gives little or no 



flame, 



