of a metallic Substance called Palladium. 301 
mercury. Their union is promoted by its action ; and the effects 
are, in all probability, simultaneous. The combination of the 
metals takes place, if I may be allowed the expression, in their 
nascent metallic state, and in a fixed proportion of mutual sa- 
turation. The union of the two metals, therefore, is in the present 
experiment less intimate, and the button which results from 
fusing the precipitate, is of much greater density. 
Exper. 3. The same process was repeated, only using zinc 
instead of iron, but the result was not more satisfactory. 
Exper. 4. I poured some mercury into a solution of platina, 
and heated them together for some time. A precipitate took 
place ; but, upon fusing it into a button, I did not find it to be 
palladium. 
Exper. 5. I dissolved the same quantities of platina and mer- 
cury as in Exper . 1 , in nitro-muriatic acid, and evaporated those 
solutions together. I then volatilized as much as I could of the 
mercury, at a red heat. At the end of the operation, I obtained 
precisely my original quantity of platina, reduced to the metallic 
state; but not one particle of the mercury remained along 
with it. 
Exper. 6 and 7. The same quantities of platina and mercury, 
dissolved in nitro-muriatic acid, were precipitated by phosphate 
of ammonia ; and the liquor was evaporated. The residuum, in 
a glassy state, was exposed to a violent heat in a charcoal 
crucible ; and I obtained a melted button, which weighed more 
than the original quantity of platina, and was of the specific 
gravity of 14,5. On account of the easy fusibility of phosphuret 
of platina, I likewise tried to combine it directly with mercury, 
but could not succeed. 
Exper. 8. I precipitated a mixed solution of platina and 
mdccciii, R r 
