QQ PRETENDED NEW METAI, J PALLADIUM. 



and immediately withdrew the apparatus from the fire. No 



fenfible union of the metals had taken place ; nor had the 



platina increafed in weight. 



Exp. 14. Mer- Exp, 14. I put 100 grains of platina into an earthen tube* 



pSd"over°igl *"^ placed the tube horizontally in the above furnace. At 



nited platina. one end of it was a retort, containing 2lbs. of mercury. 



No effea. When the tube was at its greateil heat, the mercury was made 



to boil ; and the entire quantity parted over the furface of the 



platina, at that temperature. The experiment lafted one hour 



and a half; but the metals did not feem to have combined. 



Exp. 15. Pla- Exp. J 5. Mr. Pepys was fo obliging as to try the effeB, of 



ed"?nmercu'r"^" ^^^ ^^^^ powerful galvanic battery, in forming palladium. A 



and heated by piece of platina- wire was plunged into a bafon of mercury, 



galvani^. 3,^^ formed part of a galvanic circle. The wire was nearly in 



Little efiedt. „_ ,^ ,..- , ,, ^, 



tufion; but no combmation feemed to take place. The nature 



of this experiment did not allow of very accurate weighing; 

 but the fufed globules of platina did not appear to have ac- 

 quired the properties that conftitute palladium. 



Remarks. Dlf- Such are the experiments by which I attempted to form 



pofing affinities palladium. They were chiefly founded upon two principles; 



an imi a ion. ^jfp^^fjpg affinity, and aflimilation. In the one cafe, I endea- 

 voured to prefent to the metals that compofe it, a fubftance 

 which, on account of its affinity for fome menftruum necetTary 

 for their fohition, and of their own tendency to combine in the 

 proportions flated in E.rp. I, might caufe them to unite in the 

 form of an infoluble compound. In the other cafe, I hoped to 

 affimilate the properties of each, and, by making them fome- 

 thingmore alike, to place them in the moft favourable circum- 

 fiances for uniting. Exp. 1. was founded on the former, and 

 Ejip. 8 on the latter of thefe principles. 



The platina al- In many inftances, when I did not form palladium, I obtained 



ways acquired ^ metallic button which was not platina ; and, when I did fo, it 

 weight when its .11 1 1 • • 1 • «• 1 • 



properties were always weighed more than the origmal quantity of plalma 



thus changed, employed. In repeatirtg Experimenls 1,2, 4, 6, 8, 1 1, and 12, 



Mercury was I feldom failed ot having fuch a fubllai-vce. No effe6l.of this 



iftdirpenfable. j^jj^j j^q]^ place in any experiment, when mercury was not 



ufed along with platina; and the other metals were merely 



accelTaries, in promoting their union and precipitation. This 



i% fufficiently proved, by the uniformity of the refults in 



different proceHes, whether it was palladium or the fubftanco 



I now mention which was formed. The chief property vvhtch 



diftinguilhes 



