114, Mr. Chenevix on the Action of 
paper, which contains a series of the most interesting experi- 
ments. I shall merely observe for the present purpose, that 
it very rarely happened that the mixture of two metals bore 
any determinate relation to the same metals when separate ; 
that in every case the smallest variation in the proportions 
produced the most marked effects ; and that M. RitTer has 
furnished us with an instrument calculated to detect the pre- 
sence of such small quantities as have hitherto been considered 
as out of the reach of chemistry. As palladium presents a 
very striking instance of the anomaly, to which all compounds 
seem to be more or less subject, by being removed altogether 
from the series of simple metals, this may serve to support the 
other proofs of its compound nature. 
One of the principal objections of those who dispute the 
truth of my conclusions with respect to palladium, is grounded 
upon the repeated failure of all the methods I had made use of 
in forming it ; but this cannot be of very great weight, when 
we consider the uncertainty of many other operations of che- 
mistry. The most simple are sometimes liable to fail : and the 
easiest analyses have often given different products in the 
hands of different chemists, who yet enjoy indisputable and 
equal rights to the title of accuracy. The progress which we 
have made in some parts of the science has not removed the 
obstacles which impede our advancement in others. We have 
no method of proving the truth of an experiment except by 
repeating it : yet this often tends to show nothing more than 
contradictory results, and consequently the fallibility of the 
art. 
But a recent case has occurred which is perfectly analogous 
to that of palladium. A few years ago Professor Lampadius, 
