1824.] Chemical Composition of lied Silver Ore. 33 



it there was a communication by means of glass tubes with the 

 phials holding the solution of sulphate of copper. These ao-ain 

 communicated with the ammoniacal solution of copper in the 

 other two phials, by means of glass tubes passing through corks 

 in the mouths of the phials, precisely as in a common set of 

 Woulfe's bottles. Into the glass globe E, a quantity of pulverised 

 rod silver ore was put, which, after having been gently heated, 

 weighed 1*504 gramme. Then the whole apparatus was put in 

 its place. 



When the evolution of the gas had continued for half an hour, 

 and the atmospherical air had been expelled, a spirit-lamp was 

 applied to the ball E, and a stream of gas was made to pass 

 equably and slowly. On the first application of the heat, a 

 light coloured smoke appeared, and passed over into the pipe 

 from E, but it vanished immediately, and left no trace behind it. 

 Sulphuretted hydrogen gas was immediately formed, and 

 instantly rendered the first phial turbid. Soon after a deposit 

 began to appear in the second, then in the third, and at last even 

 some deposit appeared in the fourth phial. In the ball and tube 

 not the least trace of water made its appearance, and indeed 

 nothing whatever but an exceedingly small quantity of smoke- 

 like matter. After the heat had been continued without inter- 

 ruption for eight hours, the mineral had assumed the form of a 

 metallic regulus, which easily melted by the heat of the spirit- 

 lamp. And in the throat, and tube of the little apparatus E, an 

 inconsiderable quantity of a greyish matter with the metallic 

 lustre had sublimed. When the hydrogen gas ceased to be 

 sulphureous, and the mineral to diminish any more, the gas was 

 still allowed to pass for some time. The lamp was then put out, 

 and the apparatus taken to pieces. The residue in the retort 

 was found to weigh l*23b'5 gr. The glass ball was broken, and 

 the regulus taken out ; it weighed 1*2255 gr. It had externally 

 the metallic lustre ; but was here and there covered with 

 a little black powder ; but its quantity was so small that it 

 could not be separated. Probably it was nothing else than 

 small reguli in very fine mechanical division. The tube beyond 

 the glass ball, though it contained the smoke-like matter, was 

 not sensibly increased in weight. The chloride of calcium had 

 become heavier by 0*010 gr. and it was observed that the parti- 

 cles of salt were a little soiled by a fine brownish-grey matter. 

 The hydrogen had taken from the mineral 1*504 — 1*2365 = 

 0*2075 gramme, which amounts to 17*785 per cent. 



A set of experiments was DOW undertaken on the regulus, 

 which exhibited all the characters of an alloy of silver and anti- 

 mony. The object in view was to remove the antimony by 

 cupellation, and leave the silver. But in the firsl place a set of 

 experiments was made upon an artificial mixture of silver and 

 antimony. 



New Series, v o i. . v i i i . J) 



