154 Mineralogy and Geology of apart of Nova Scotia. 



formed on the surface of the fluid, which was the sulphur 

 extricated from the ore. When cool, the contents of the 

 matrass being diluted with pure water, and carefully washed 

 from its surface, were thrown on a filter of known weight. 

 The precipitate collected on its surface, washed with dilute 

 nitric acid, and afterwards with water, being dried, was 

 found to weigh thirty- eight grains. This was ignited in a 

 crucible of platinum over an alcohol lamp, and burned away, 

 leaving two grains of a dark grey powder, which was a por- 

 tion of the ore that had escaped decomposition. This was 

 treated with nitro-muriatic acid, and being dissolved by it, 

 was added to the filtered solution. The sulphur then in two 

 hundred grains amounts to thirty-six grains, or eighteen per 

 cent. 



C. The liquid which had passed the filter was of a bluish 

 green color, and transparent. It was divided into two equal 

 quantities. In one portion a polished cylinder of iron was 

 immersed, and in forty-eight hours the copper had precipi- 

 tated upon it in a dendritic form. That it had entirely sep- 

 arated the copper was known by the solution ceasing to give 

 a tarnish of copper to a polished steel instrument. The 

 copper removed from the cylinder of iron, washed and dried 

 rapidly to prevent oxidation, was found to weigh 79.5 grains. 



D. The other half of the solution was treated with aqua 

 ammonioe to excess of saturation, when a muddy brown pre- 

 cipitate took place, which, when collected on a double fil- 

 ter of known weight, washed, dried, and ignited with a little 

 wax in a platinum crucible, was reduced to the protoxide of 

 iron attractable by the magnet, and weighed 3.4 grains, indi- 

 cating 2.5 grains of metallic iron. 



E. To determine whether the solution was equally divided, 

 and to prove the correctness of the process C.the ammoniated 

 solution was saturated and acidulated with sulphuric acid, 

 and a plate of polished iron immersed in it. The copper pre- 

 cipitated in a brilliant metallic coating, and when separated, 

 washed and dried, weighed with the loss of a trifling fraction, 

 like the result of the former process 79.5 grains. 



This ore contains, then, in a hundred parts, 



Copper, - - - - (C) 79.5 



Sulphur, (B) 18.0 



Iron, (D) 2.5 



100.0 



