of a metallic Substance called Palladium. 313 
Experiments 9, 10, 11, 12, and 13. With a solution of platina 
and arsenic acid, muriate of tin gives no precipitate; but the 
colour of the liquor is more heightened than if the platina had 
been alone in solution. Platina and antimony give a precipitate 
by this reagent, after standing some time ; but the effect is re- 
tarded by the excess of acid in the solution of antimony. Platina 
and copper, also platina and lead, are acted upon as the separate 
solutions of these metals. Platina and silver are precipitated 
together by green sulphate of iron. 
Experiments 14, 15, 16. Mercury and copper, mercury and 
lead, also mercury and arsenic, are precipitated in the metallic 
state by recent muriate of tin. 
From these experiments it is evident, 
1st. That gold has an affinity for mercury, for antimony, 
and for arsenic. 
2d. That platina has an affinity for silver, for mercury, and 
for antimony ; and that it is influenced by the presence of arsenic. 
3d. That silver has an affinity for mercury. 
4th. That mercury has an affinity for copper, for lead, and 
for arsenic. 
This series of experiments is not intended as a system of metallic 
affinities ; but as a few facts stated to corroborate an assertion. 
I am well aware that many others might be noticed ; but it is 
not my intention to enter further into this subject, in the present 
Paper. The general importance of the principle, and the ex- 
tensive influence it is likely to have upon chemistry, demand 
that it should be treated by multiplied researches.. The experi- 
ments that can elucidate it are of the most delicate nature, and 
require peculiar care ; for they do not always succeed, unless 
performed under the most favourable circumstances. 
