176 



in order to ascertain the matter, he observed the methods recom- 

 mended by those chemists for obtaining pure platina, but did not 

 perceive any difference in the facility with which either kind of pla- 

 tina combined with mercury. 



Mr. Chenevix then adverts to the experiments of Messrs. Rose and 

 Gehlen, who attempted to repeat some of the processes described by 

 him for the formation of palladium. The experiments of those gen- 

 tlemen were unsuccessful ; but this, Mr. Chenevix considers as not 

 militating against his experiments, as he shows that the processes 

 made use of by them, though meant to be an exact imitation of his, 

 were, in fact, materially different. The same gentlemen, Mr. Che- 

 nevix says, seem to question his having fused platina, as they could 

 not succeed, although they exposed it to. a heat, the degree of which 

 Wedgwood's pyrometer ceased to mark. Upon this Mr. Chenevix 

 remarks, that they do not mention their having made use of any flux; 

 whereas he employed borax for that purpose. He then describes, at 

 full length, the method used by him, which consists in filling a Hes- 

 sian crucible with lamp-black pressed hard together, and placing the 

 platina, surrounded by borax, in the centre of the lamp-black, at the 

 bottom of which there is previously formed a cavity to receive the 

 platina when fused. 



Mr. Richter also attempted to make palladium by the process 

 which Mr. Chenevix describes as the best for that purpose, but failed. 

 He was, however, convinced by his trials, that " mercury is capable 

 of entering into combination with platina, so that it cannot afterwards 

 be separated by fire." 



It appears also that Mr. Trorasdorff, and likewise Mr. Klaproth, 

 have made some fruitless attempts to obtain palladium. As these 

 gentlemen, as well as Messrs. Rose and Gehlen, and Mr. Richter, 

 seem disappointed at their want of success, Mr. Chenevix takes oc- 

 casion to observe, that they appear to have placed a reliance upon 

 his processes, which his words did not authorize ; and says that his 

 paper, " as far as regards palladium, is rather a narrative of fruitless 

 attempts, than a description of an infallible process, and more likely 

 to create aversion to the pursuit, than to inspire a confidence of suc- 

 cess." 



The compound nature of palladium, Mr. Chenevix thinks, has re- 

 ceived some support from the galvanic experiments of Mr. Ritter, 

 who found its galvanic properties different from what they ought to 

 be, upon the supposition of its being a simple metal. 



As a further excuse for the failure that has attended the repetition 

 of his processes, Mr. Chenevix mentions that Prof. Lampadius, a 

 few years ago, " in distilling some substances that contained sulphur 

 and charcoal, obtained a peculiar liquid, which he called sulphur-al- 

 cohol ; and that, after many fruitless attempts to procure the liquid 

 a second time, he abandoned his researches. Messrs. Clement and 

 Desormes, however, some time after obtained this liquid, but were 

 equally unsuccessful in their numerous attempts to produce it again. 

 In February last, Professor Lampadius accidentally discovered, and 



