410 CLOUD, ON PALLADIUM FOUND IN GOLD. 



added to the decanted fluid, now holding nothing but palla- 

 dium in solution. 



Pro. 4th. A saturated solution of pure pot-ash (carbonate of 

 pot-ash did not succeed so well, part of the palladium being 

 held in solution by the carbonic acid) was added to the me- 

 tallic solution from process 3d, untd the whole of the palladi- 

 um was thrown down in form of a floculent orange-coloured 

 precipitate. The precipitate was collected on a nitre; — was 

 well washed with pure water, and dried. 



Pro. 5th. A portion of the precipitate from the last process 

 was put into a crucible, without addition, and subjected to a 

 heat of about 60° of Wedgewood; and thus, a metallic button 

 of palladium was obtained. 



Pro. 6th. Another portion of the precipitate from process 4th 

 was combined with black flux, and submitted to a degree of 

 heat equal to that excited in process 5th, and similar results 

 were obtained. 



Having thus obtained a metal, which I supposed to be pal- 

 ladium, from a source heretofore unknown; in order still far- 

 ther to satisfy myself, I separated that metal from crude plati- 

 num, and subjected them both to a number of comparative 

 experiments, with prussiate of mercury, recent muriate of tin, 

 and other re-agents, without discovering the least shade of dif- 

 ference. 



Palladium is of a greyish-white colour; so closely resembling 

 that of. platinum, that "they cannot be distinguished by their 

 complexion. It is malleable, and very ductile; so that by the 

 rolling-mill it can be reduced into thin plates. In hardness it 

 is nearly equal to wrought iron. Its specific gravity, at 64° 

 Fahrenheit, is 11~- II ma y be a U°y ctl witil a number of the 

 metals. With gold, silver, and platinum, it forms ductile alloys, 

 and very much debases the colour of the two former. 



It would be useless here to go into a further detail of the 

 characters and properties of palladium, as Dr. Wollaston and 

 Mr. Chenevix have fully explained them, in the Philosophical 

 Transactions of the Royal Society of London, for 1803-4 and 5. 

 It is enough for me to have shown, I trust satisfactorily, that 

 palladium has a real existence; that it is one of the pure or 



