HISTORY OF GOLD, 239 



the latter, which is the real solvent of the gold, should predo- 

 minate in the aqua regia. The same things take place in the Platina com- 



, . /. 1 , • ports itself like 



solution ot platma. ^^1^ 



To obtain the muriate easily in a crystallized state, it is ad- Muriate of gold 

 visable to keep an excess of gold in the solution, and to add 

 muriatic "acid from time to time, till it is perceived to act on 

 the gold no longer. By proceeding thus the nitric acid is ex- 

 hausted, and at the end there remains none to disturb the 

 crystallization. 



The solution evaporated to a certain point gives a lamella- 

 ted crystallization, but a coagulated one if it be concentrated 

 too much. This muriate is so liquefiable, so difficult to obtain Extremely de- 

 dry, and of course without risking considerable loss, that it ^^^^^^'^^^ • 

 scarcely ought to be taken out of the retort, if we have no 

 other object in view but to exhibit it. In summer it becomes 

 liquid in the morning, and crystallizes towards evening, 

 and passes through this alternation during the continuance 

 of the hot weather. 



The t?Lste of the pure muriate is ascerb with a little bitter- Acerb, and 

 ness, but without that after taste of metal, which render the ^^'^^^^^ ^*^*^'"' 

 solutions of silver, copper, &c,, so disagreeable. 



The muriate of gold is perfectly soluble in spirit of wine. Soluble in al- 

 This solution assisted by heat experiences no change ; the al- ^'^"°^' 

 cohol is not converted into ether ; distillation separates them, 

 and the muriate is recovered unchanged. 



This muriate being distilled gives out abundance of water Decomposed 

 and oxigenated muriatic acid. The gold remains spongy and •^ ^^. ' 

 without lustre at the bottom of the retort. The vapours carry 

 over some of the muriate of gold, which is found in the receiv- 

 er ; but very little, as Boyle observed. The decomposition of 

 the muriate of gold exhibits the same appearances in every 

 Tespect as that of the muriate of platina: both yield oxigena- 

 ted acid and pure metal. 



Auriferous Ether. 



Sulphuric either takes the muriate from the solution of gold Sulphuric ether 

 and leaves the nitric acid alone. The crystallized muriate too 'bssoives it, 

 dissolves in it with the greatest facility, and without residuum. 



The auriferous ether on exposure to the air loses its solvent, but will evapo- 



and is reduced to a yellow, acerb liquid, which is always pure ^ate and leave 



■^ ■' . the nsuriate un- 



munate changed. 



