Page:Proceedings of the Royal Society of London Vol 1.djvu/196

Rh 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 militaﬁng 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 horax 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. Tromsdorff, 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 aconﬁdence 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. Lampadins, a. few years ago, “ in distilling some substances that contained sulphur and charcoal, obtained a peculiar liquid, which he calied sulphur-al- cohol; and that, after many fruitless attempts to procure the liquid is second time, he abandoned his researches. Messrs. Clement and Desormes, howaver, 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