from their Ores hy tJie Wet Way, 7 



gold, as the manipulation was hardly conducted with the 

 requisite care. 



I dried the residual ore, and by trituration reduced it to a 

 very fine state of division, so that it was passed through the 

 finest copper sieve. I suspended it in cold distilled water, 

 and passed through a stream of CI during about a quarter of 

 an hour, stirring continually. I then digested on the sand- 

 bath, and left till the next daj', when 1 still perceived a faint 

 odour of CI. I added 100 grs. of hyposulphite of soda, and 

 digested at a gentle temperature, stirring occasionally. I de- 

 canted and filtered the supernatant liquor. I again digested 

 the residue with an additional quantity of 100 grs. of hypo- 

 sulphite, filtered and washed. I boiled the filtrate, as usual, 

 with an excess of dilute SO^. The precipitate soon became 

 dark-coloured. I digested until the supernatant liquor be- 

 came clear, filtered, washed and dried. I detached the pre- 

 cipitate from the filter, which was done without appreciable 

 loss; heated it in a capsule, to expel the free sulphur, and 

 digested it with aqua regia. As the white product which was 

 obtained by this means was mixed with minute acicular cry- 

 stals like chloride of lead, I treated it, after washing, with zinc 

 and dilute hydrochloric acid. I washed and dried the metallic 

 residue, enclosed it in 110 grs. of assay lead, and cupelled. I 

 obtained a bead of fine silver weighing 0*829 gr., making a 

 total of fine silver 6-298. 



I examined the liquid left after digestion of the first preci- 

 pitate with aqua regia, for gold. I diluted it considerably, 

 and boiled with oxalic acid. On the following day (the oxalic 

 acid being added at night) I observed a film of reduced gold 

 of a reddish-brown colour; and a few days afterwards I 

 distinctly recognised minute particles having the colour and 

 metallic lustre of gold. 



10. I treated 1000 grs. of the well- roasted ore, in its coarsely 

 pounded state, with a cold solution of Fe^ Cl^, Fe^ O^ was 

 soon precipitated, being displaced doubtless by the oxide of 

 zinc *. The supernatant liquor became clear and colourless. 

 I added HCI, which redissolved the Fe^ Cl^, but it was again 

 precipitated. I added a considerable quantity of HCI, and 

 obtained a greenish-yellow brown solution. I filtered and 

 washed, and treated the residue with a solution of 150 grs. of 

 hyposulphite of soda. I proceeded as uusul with SO^. I 

 used 200 grs. of assay lead in the cupellation, and obtained a 

 bead of fine silver weighing 4*909 grs. 



1 1. I confirmed the fact, that when chloride of silver is dis- 

 solved in a solution of hyposulphite of soda, and treated with a 



* Oxide of copper will also displace it. 



