l^t- ACTIO!* or PLATINA AND 



MERCURY. 



—infer that pal- No fooner were thefe celebrated chemifts convinced of the 

 i';*''';'"""^"' exiftence of a new metal in plalina, than they concluded that 



no mercury j but , r ' j 



is platina with it muft play a principal part in the compofition of palladium. 



D^fcoUls'"'^'^^^^^^^'^ aa«r this, in a note to a letter from M. Prouft to M. 

 Vauquelin, in which M. Prouft expretTes his aftonifliment 

 c,^ concerning all he has read upon palladium, MetT. Fourcroy 



•'' and Vauquelin further declare, as their opinion, that this com- 



pound metal does not contain mercury, but is formed of platina 

 and the new metal. Whether this new fubftance does ordoes 

 not play a principal part in the formation of palladium, could 

 not be afcertained at the time my experiments were made, 

 becaufe the new metal itfelf was not then known. Kut from 

 all that Meir. Fourcroy and V^auquelin have ftated, in fuch of 

 their diffcerent memoirs upon this fubje6l as I have feen, the 

 grounds of their fuppofition have not appeared. May we not 

 refer their opinion, then, to that common propenfity of the 

 mind, againft which M. Fourcroy has himfelf warned us with 

 equal juftnefs and eloquence on another occafion, namely, 

 a pronenefs to be allured by novelty beyond the bounds of 

 rational belief, and to convert principles which are new into 

 principles of univerfal influence. 

 Mcff. Rofc and MeiT. Rofe and Gehlen* were the fir ft among the German 

 Gehlcn, chemifts who inftituted experiments upon palladium ; and M. 



Kichter has alfo publilhed a paper on the fame fubjefl. 

 •-attempted The fifft attempt of MetT.Rofe and Gehlen to form pal- 



without /uccefs ladium was by th^ precipitation ot-a mixed folution of platina 

 diumTy^m^c'ipi- ^"^ mercury by green fulphate of iron. Their refult was pre- 

 tating a mixed cifely that which I had obferved when my operations failed 



folationof p'u- aJiQ^ether, and which of courfe was the moft frequent. This 

 tioa and mercury 6 » ^ , r j • 



by gr. fulphate method was repeated twice. The fecond time the precipitate 

 ot iron J qP platina and mercury was boiled with muriatic acid, in order 



to free it from iron j but the latter trial was not more fuccefs* 



ful than the former, 

 —and alfo by Their third experiment was, what they have called, a repe- 

 paifing fulphu- tJtion of that in which I had obtained palladium by palling a 

 through the" current of fulphuretted hydrogen gas through a mixed folution 

 mixed folution J of platina and mercury. Their method was the followingyi 



* Neues Algcmeines Journal der Chemie herau fgegeben von 

 Hermftadt, Klaproth, Richter, Scherer, Tromfdorff, und Gehlen. 

 Erften bandes funftes heft. 



They 



