48 Chlorine as a Solvent of Gold. 



Experiments which I have performed since the death of 

 my friend with sea-sand and gold, in a state of as minute 

 division as I could reduce them to, also favoured this view 

 in a remarkable manner. Five grains of gold dust, or 

 powder, obtained from precipitating it from the per-chloride, 

 were divided into two equal parts, and each mixed with an 

 equal weight of gold in a minute state of division already, 

 each of these was then mixed with 5,000 grains of sea-sand, 

 and the whole pounded together till it was in a fine powder. 

 They were then each separately mixed with 5,000 grains of 

 coarser sand, quartz-sand, and one submitted to amalgama- 

 tion with mercury, and the other to the action of chlorine 

 gas in a wooden vessel. The chlorine was forced into the 

 sand, and then washed through with cold water. I obtained 

 from five grains of gold in 10,000 grains sand, by the mercury 

 process, 3.210 grains ; by the chlorine process, five grains in 

 10,000 sand, obtained 4.62 grains. 



There appeared, after distilling over the mercury, that a 

 very minute portion of gold adhered to the side of the vessel, 

 (a Bohemian glass retort), a thin film, not more than a 

 minute fraction of a grain. 



I quote this as one of several experiments made some- 

 times with roasted quartz-rock, at others with sea-sand, and 

 at others with both mixed, but always with a definite quan- 

 tity of gold in a state of minute division. 



I have not yet performed a sufficient number of experi- 

 ments to satisfy my own mind as to the interference with 

 thee hlorine, and its probable loss from metals or their oxides, 

 as found associated with gold in the matrix. But from such 

 as were made by Count Dembinski, by both of us, and 

 latterly by myself, I anticipate little or none. When the 

 quartz has been properly calcined previous to powdering, the 

 chlorine will have no more action on the metallic oxides 

 than upon the quartz itself. The titanic and magnetic iron, 

 and the particles of iron introduced during the process of 

 stamping, may be ehminated by a simple and inexpensive 

 process, as follows : — 



The ore at Bichenstein, is an arsenical pyrites, contain- 

 ing about 200 grains of gold in the ton. The ore is roasted 

 in a reverberatory furnace, surmounted by a large condens- 

 ing chamber, in which arseneous acid is condensed as fast as 

 it is volatilized. There then remains on the floor of the 

 furnace oxide of iron mixed with a certain quantity of 

 arsenic, together with the whole of the gold. This is placed 



