122 



excite the curiosity of several mineralogists ; and among these, Mr. 

 Chenevix, to whom the manner in which this object was presented 

 to the public appeared suspicious, was among the foremost in pro- 

 curing a sufficient quantity of the substance to enable him to insti- 

 tute a proper analysis by which the fallacy, if there were any, might 

 be detected. The substance, as exposed to sale, had been worked by 

 art : it had been rolled out in flatting-mills, the largest of the lamina 

 being about three inches in length and half an inch broad, and 

 weighing on an average twenty-five grains each. It had much the 

 appearance of platina ; but its specific gravity was so low as from 

 10'972 to 11*482; that of pure platina in the same state being at 

 least 22. The laminae were flexible, but not very elastic. 



After describing these its physical properties, the author proceeds 

 to a circumstantial account of his chemical analysis, and gives an 

 ample detail of the action, on this metal, of caloric ; of simple com- 

 bustible bodies, such as sulphur and charcoal ; of other metals, form- 

 ing various alloys ; of alkalies and acids, in the latter of which he 

 found that the true solvent of palladium was nitro-muriatic acid, 

 which attacked it with great violence, and formed a beautiful solu- 

 tion ; and lastly, he mentions the appearance and principal proper- 

 ties of the precipitates from its various solutions. From the results 

 of this investigation we learn, that the vender of this substance was 

 not guilty of misrepresentation when he ascribed to it the following 

 properties : 



1. It dissolves in pure spirit of nitre, and makes a dark red solu- 

 tion. 



2. Green vitriol throws it down in the state of a regulus from this 

 solution, as it always does gold from aqua regia. 



3. This solution, when evaporated, yields a red calx, that dissolves 

 in spirit of salt or other acids. 



4. It is thrown down by mercury and by all the metals except 

 gold, platina, and silver. 



5. In a common fire the face of it tarnishes a little, and turns 

 blue ; but comes bright again, like other noble metals, on being 

 heated to a greater degree. 



6. The greatest heat of a blacksmith's fire will hardly melt it. 



7. But if touched while hot with a small bit of sulphur, it runs as 

 easily as zinc. 



After maturely considering the results of his experiments, and 

 comparing them with the analogous ones made on the various known 

 metals and combinations of metals, our author acknowledges that he 

 does not find to which of them it may be assimilated. The striking 

 resemblance, however, of several of the precipitates of palladium with 

 that of platina, first led to the suspicion, that if the former be a com- 

 bination, the latter is no doubt one of its principal ingredients. 



The stubborn circumstance of the very low specific gravity appeared 

 one of the most difficult to be surmounted ; since an alloy of platina, 

 even with tellurium, the lightest of all metals, would not by calcula- 

 tion give so low a standard. 



