CLOUD, ON PALLADIUM FOUND IN GOLD. 409 



high brownish-red colour. The metals remaining undissolved, 

 after being well washed with pure water, and ignited, weighed 

 22 carats 11. grain; and had every appearance of pure gold. 



Exp 4th. The metals remaining undissolved in the last ex- 

 periment, were submitted to the action of nitro-muriatic acid. 

 The whole was dissolved, except a small portion of silver that 

 had escaped the action of the nitric acid : the solution was 

 tested for platinum, by muriate of ammoniac and other re- 

 agents, witbout any indications of the presence of that metal. 

 The gold was precipitated, and found to have been pure to 

 ttt part. 



Exp. 5th. To the metallic solution from experiment 3d, I 

 added some pure muriatic acid, until the silver was precipitat- 

 ed, and the acid was in considerable excess : there was no pre- 

 cipitation of the colouring matter of the solution, which still 

 retained its red colour, and did not appear to have undergone 

 any change by the precipitation of the silver. 



By these preliminary experiments I discovered, that the al- 

 loy was a compound of gold, and a metal that would resist the 

 cupel, and was soluble in the nitric and nitro-muriatic. acids. I 

 therefore adopted the following mode of analysis, as the easiest, 

 and at the same time a satisfactory evidence of the existence 

 of a metal possessing the properties of palladium; by which 

 name I shall call it in future. 



Process 1st. The whole ingot was combined with double its 

 weigbt of tine silver, and cupeled with a quantity of lead, equal 

 to the weight of the compound. 



Pro. 2d. The cupeled metals were reduced to thin plates, 

 and submitted to the action of boiling nitric acid, until the sil- 

 ver and palladium were dissolved. The solution, which was of 

 a high brownish-red colour, was decanted, and the residual 

 gold washed with pure water, which was added to the decant- 

 ed solution. 



Pro. 3d. Pure muriatic acid was added to the metallic solu- 

 tion of process 2d, until no further precipitation took place, 

 and the acid was in excess. The silver being completely pre- 

 cipitated, the fluid, which retained its red colour, was decanted* 

 and the precipitate washed with pure water : the washings were 



