Royal Society of London. ^6^ 



College of Pharmacy to adopt among its experiments, which 

 form a part of its annual public courfe of chemiftry, the tree 

 of Saturn, as proper for proving in a precife manner the ftrong 

 attra£lion of zinc for oxygen. This experiment, which is not 

 very expenlive, always fucceeds, and deferves a place in mi- 

 neralogical cabinets along with the tree of Diana. 



LXV. Proceedifigs of Learned Soc'ietles. 

 ROYAL SOCIETV OF LONDOX. 



± HE meetings of the 12th and jQth of May were occu- 

 pied by the readuig of a paper, by Mr. Chenevix, on a me- 

 tallic fubrtance, of which we have fpoken in our la'i Number. 

 Jt was announced to the public by its author as a new fnnple 

 nietal Jul generis, under the title of Palladium, or new Silver. 



Mr. Chenevix made a number of experiments on this fub- 

 ftance, and found that, in molt refpcAs, it was really different 

 trom all the known metallic bodies. In a few, however, it 

 bore fome reiemblance to platina. But it was not poffible to 

 conceive that platina could be reduced to the fpecific gravity 

 o^ ii-8; could be fufible at fo moderate a heat; could com- 

 bine with fulphur; could be diffolved by nitric acid, and be 

 precipitated by green fulphate of iron. Thofe are the pro- 

 perties mentioned in the printed notice we received laft 

 month, and which we infertcd in our Journal. Mr. Che- 

 nevix found them to be truly Itated. 



Kefleding, however, upon the extraordinary anomalies that 

 happen when fubltances are united, it occurred to him that 

 fome melal might fo far influence platina as to promote its 

 piecipitaiion by green fulphate of iron, and be itfelf drawn 

 down along with it. Mercury was the firit that prelented 

 itfelf to his mind, as the molt eadly reduced. He poured a 

 folulion of green fulphate of iron into a folution of platina: 

 no precipitate. Into a folution of muriate of mercury : no 

 precipilite. He mixed the two folution?, and a precipitate, 

 exactly refembling that produced in palladium, in)niediatc!y 

 enfued. I Je reduced this precipitate ; and, after fcveral trials', 

 at length fucceeded in obtaining a fubllance exadly liuiiiar 

 to palladium. From all his exV'riments, which are nuich 

 too numerous for this extract, Mr, Chenevix does not hefitale 

 to pronounce palladium to be a fcandalous impofiiion, and 

 an attempt to defraud the public as well as to dilgrace fcience. 



I'Vom lynihelis and analyfis it appears that~"palladiiun of 

 the fpecilic gravity of i 1-5 contains about one-tlnrd of mer- 

 cury; and wlieii of the fpecilic gra\ity ol ja-j, about one- 



fuurlh. 



