GOLD. M3 



in distilled water. The salt melted and boiled, 

 and was gradually deprived of its water ; as soon 

 as it became dry, chlorine gas was given out 

 very rapidly at first, but more and more slowly, 

 as the heating continued. This gas was absorbed 

 by the nitrate of silver solution, and occasioned 

 a precipitate of chloride of silver. 



This experiment is attended by two difficul- 

 ties, which it cost me some practice to obviate. 

 The first is, the tendency which the liquid has to 

 make its way into the red hot retort, in conse- 

 quence of the absorption of the chlorine gas. 

 This difficulty was obviated by having a contri- 

 vance for letting common air into the retort 

 when the absorption began to threaten the de- 

 struction of the retort. The other difficulty is, 

 the application of the requisite degree of heat to 

 reduce the gold completely to the metallic state. 

 Quite different from muriate of gold, this triple 

 salt bears an incipient red heat with impunity, 

 and it was not till after two or three failures that 

 I became aware of the necessity of raising the 

 fire as high as the glass would bear without 

 melting, which was a distinct red heat, and 

 keeping it up at least a couple of hours. 



Three different successful experiments were 

 made, with three different objects in view. In 

 the first, I determined the weight of gold con- 

 tained in 5O5 grains of the triple salt ; in the 

 second, the whole of the chlorine was combined 



