214 THE CANADIAN NATURALIST. [June 



Yale College. Tt was first crushed, and sifted to separate the coarse 

 gold, after which that portion which was finely disseminated was 

 separated by roasting, fluxing, and cupellation. The results calcu- 

 lated for 2000 lbs. gave of coarse gold 0.5676, and of the diffused 

 gold 0.2740 ; = 0.9419 lbs., or 13 oz. 12 dwts. 22. grs. of gold 

 to the ton of mispickel. This gold contained only 3.34 per cent 

 of silver. 



The separation of the gold from the sulphurets must be a chemi 

 cal process, and it is a question whether the cost of extraction may 

 not exceed the value of the gold obtained. In the gold mines of 

 Virginia and North Carolina, the surface of the tailings-bank is 

 plowed over, and the sulphurets are thus exposed to the action of 

 the weather; when a sufficient time has elapsed, the surface 

 tailings are run through the mill. This is always found to pay ex- 

 penses, and leave a profit. During the month of August thea^ent 

 of the Chebucto Company of Waverley treated a quantity of tailings 

 in this manner, and was surprised to find that the results would 

 pay all expenses, and leave a balance. 



After the lot of quartz has been crushed, the mill cleaned-up, 

 and the whole of the mercury used is washed free from all silicious 

 particles and sulphurets, it is the custom with some to allow 

 the mercury to stand for some hours, when the amalgam settles to 

 the bottom, and the free mercury can be poured off for future use ; 

 or the whole quantity may be subjected to pressure in chamois 

 leather, when the superfluous mercury is forced out through the 

 pores of the leather, leaving the amalgam in the shape of a silvery 

 pasty mass ; but whichever means may be adopted, a certain 

 quantity of dissolved gold passes away with the mercury, which, 

 it is said, is beneficial in promoting amalgamation in future 

 operations. 



The separation of the gold from the mercury is performed in the 

 operation of retorting. The retort is a cast iron vessel, conical in 

 shape, having a cover which is made to fit extremely tight, to 

 prevent the escape of the fumes of the mercury. In the cover is 

 inserted a bent iron tube. The amalgam is placed in the retort, 

 the cover securely fastened down, and the whole apparatus placed 

 in the fire and covered with fuel. So soon as the mercury begins to 

 distill over, the end of the tube is plunged into cold water, and a 

 small stream of water is allowed to fall on the tube itself; when 

 the mercurial vapor condenses and assumes its original form. Heat 

 must be kept up until all the mercury has passed over, when the 



