of a metallic Substance called Palladium . 307 
of some philosophers, who supposed that the rapidity of combi- 
nation was a measure of the force of affinity. We do not 
know of any affinity among chemical bodies which is more 
powerful than that of platina and mercury appears to be. The 
obstacles which must be overcome, in order to fix the latter metal, 
are a proof of this ; yet the difficulty of forming this combination 
to its full extent is extreme. The difference which exists between 
the compound and its elements, when merely mixed, either in 
solution or otherwise, cannot be better exemplified than by 
comparing the result of the 5th synthetical experiment, with the 
difficulty of expelling mercury from the compound. 
I must here observe, that all the analytical experiments, and 
many others, were made, by way of comparison, upon the palla- 
dium I had bought, as well as upon that which I had made. But, 
although I had myself combined the mercury with the platina, 
and consequently knew it to be in the compound that resulted, 
I could not succeed in separating it. Neither did the substance 
described in a former paragraph, as intermediate between platina 
and palladium, allow one particle of mercury to escape from it, 
by any process I have yet been able to devise. 
The name of palladium conveys to our mind the idea of 
something absolute, and therefore incapable of gradation. But 
gradations in alloys are infinite ; and the alloy of platina and 
mercury is susceptible of infinite variation. Palladium also 
brings to our recollection a contemptible fraud directed against 
science : the name, therefore, should not be admitted. I have 
called it an alloy ; for it differs too much from the usual idea 
we have annexed to the word amalgam, but it accurately corre- 
sponds with our notions of the name I have adopted. 
The facts which I have related in this Paper, appear at first 
