Platina and Mercury upon each other. 27 



made upon them, and M. Guyton was the person appointed 

 for the purpose. He repeated some of the experiments, and 

 produced some of his results. His general conclusion was 

 the same as mine. 



Messrs. Vauquelin and Fourcroy then undertook the sub- 

 ject, and they were led by it to the confirmation of the re- 

 cent discovery of M. Descotils. The existence of a new 

 metal which that chemist had found in crude platina, re- 

 ceived great sanction from iheir experiments ; and thus the 

 discussion upon palladium has established a fact which will 

 be considered as interesting, but which would be much 

 more so, were we not already overburthened with substances 

 which our present isfnorance oblioes us to acknowlediie as 

 snnple. 



No sooner were these celebrated chemists convinced of 

 the existence of a new metal in platina, than they concluded 

 that it must play a principal part in the composition of pal- 

 ladium. Shortly after this, in a note to a letter from 

 M. Proust to M. Vauquelin, in which M. Proust expresses 

 his astonishment concerning all he has read upon palladium, 

 Messrs. Fourcroy and Vauquelin further declare, as their 

 opinion, that this compound metal does not contain mer- 

 cury, but is formed of platina and the new metal. Whe- 

 ther this new substance does or does not play a priiicipal 

 part in the formation of palladium, could not be ascertained 

 at the time my exjceriments were made, because the new 

 metal itself was not then known. But from all that Messrs. 

 Fourcroy and Vauquelin have stated, in such of their dif- 

 ferent memoirs upon this subject as I have seen, the grounds 

 of their supposition have not appeared. May we not refer 

 their opinion, then, to that common propensity of the 

 mind, against which M. Fourcroy has himself warned us 

 with equal justness and eloquence on another occasion, 

 namely, a proneness to be allured by novelty beyond the 

 bounds of rational belief, and to convert principles which 

 are new into principles of universal influence. 



Messrs. Rose and Gehlen * were the first among the 

 German chemists who instituted experiments upon palla- 

 dium ; and M. Kichtcr has also published a paper on the 

 sante subject. 



The first attempt of Messrs. Rose and Gehlen to form 

 palladium was by the precipitation of a mixed solution of 

 platina and mercury by green sulphate of iron- Their re- 



• Xeues jilgemrines Jour/ml <hr Clnmir hcrnusgr^chcn inn Ucrm.'itadt, KJap- 

 roth, Richter, ijcherer, Tromsdorf, unci Gehlen. Erstcn landn funj'tcs 

 hejl. 



6 Eult 



