324. Dr. Wollaston on the Discovery of Palladium. 
for palladium that possesses little power of acting on platina, 
so that by digesting any quantity of the second metallic preci- 
pitate till there appeared to be no farther action, I procured 
a solution from which by due evaporation were formed crystals 
of a triple salt, consisting of palladium combined with muriatic 
acid and potash. These are the crystals which I have on a 
former occasion * mentioned as exhibiting a very singular 
contrast of colours, being bright green when seen transversely, 
but red in the direction of their axis ; the general aspect, 
however, of large crystals is dark brown. 
From the salt thus formed and purified by a second crys- 
tallization, the metal may be precipitated nearly pure by iron 
or by zinc, or it may be rendered so by subsequent digestion 
in muriatic acid. 
§ V. Reasons for thinking Palladium a simple Metal. 
From the consideration of this salt alone I thought it highly 
probable that the substance combined in it with muriate of 
potash was a simple metal, fori know of no instance in chemistry 
of a distinctly crystallized salt containing more than two bases 
combined with one acid. I nevertheless endeavoured by a suit- 
able course of experiments to obviate all probable objections. 
After examining by what acids it might be dissolved and by 
what reagents it might be precipitated, I combined it with 
various metals, with platina, with gold, with silver, with 
conoer, and with lead ; and when I had recovered it from its 
alloys so formed, I ascertained that, after every mode of trial 
it still retained its characteristic properties, being soluble in 
nitrous acid, and precipitable from thence by mercury, by green 
* Phil, Trains. 1804, p. 428. 
