1016 



SCIENCE. 



[N. S. Vol. XI. No. 287. 



a few hammer blows while in the furnace. 

 This gave a coherent platinum which could 

 be readily worked into an ingot. It was just 

 about the opening of the century that the 

 discovery of platinum in the Ural Moun- 

 tains occurred,* and the supply being thus 

 very materially augmented, the use of 

 platinum in the laboratory became estab- 

 lished. At the same time the study of the 

 metal from a chemical standpoint led to the 

 discovery of several other metals in the 

 platinum ores. No less than five of the 

 distinguished chemists of that day were 

 working on the ore, with the special aim 

 of separating out other metals which they 

 had reason to believe were present. Palla- 

 dium was first obtained by WoUaston ; Col- 

 let Descotils was the first to publish indica- 

 tions of what we now know to be iridium, 

 and Fourcroy and Vauquelin at the same 

 time had this metal in hand in an impure 

 form. The real discoverer of iridium 

 should be recognized in Smithson Tennant, 

 who not only separated it in purity, but 

 also at almost the same time found in the 

 same residues the element osmium which 

 seems to have been wholly overlooked by 

 the French chemist. This chapter was 

 closed a few months later by Wollaston's 

 discovery of rhodium. 



The episode of the discovery of palla- 

 dium throws a curious light upon the chem- 

 istry and chemists of that period. On May 

 12, 1803, Chenivix read a paper before the 

 Koyal Society f stating that two weeks pre- 

 viously (April 29th) he learned by a printed 

 notice that a substance announced as palla- 

 dium, a new metal, was offered for sale at 

 the establishment of a well-known mineral- 



*Osanii says [Ann. der Phys. (Pogg. ) 11, 311 

 (1827)) that the first mention he can find of platinum 

 in connection with the Ural Mountains is Ann. de 

 Chim., 60, 317 (1806), where Vauquelin speaks of a 

 rumor that platinum has beeu discovered in Siberia. 

 Osann could not trace the origin of this rumor. 



tPM. Trans., 93, 290 (1803). 



ogist. The printed notice* opens : " Pal- 

 ladium, or new silver, has these properties 

 among others which show it to be a new 

 noble metal " and then follows the enumera- 

 tion of eight characteristics of the metal, 

 closing with the address where the new 

 metal could be bought. Chenivix goes on 

 to say that the mode adopted to make known 

 a discovery of so much importance without 

 the name of any creditable person, except 

 the vendor, appeared to him unusual and 

 not calculated to inspire confidence. Hav- 

 ing examined a small sample, Chenivix 

 returned and purchased the whole supplj^ 

 He then says : ' ' We shall cease to wonder 

 at what has been related by these chemists 

 (Berthollet on affinity and Hatchett on 

 alloys), when we learn that palladium is 

 not as was shamefully announced a new 

 simple metal, but an alloy of platina ; and 

 that the substance which can thus mask 

 the most characteristic properties of that 

 metal, while it loses the greater number of 

 its own is mercury. Chenivix however on 

 May 4th had written f to Vauquelin that 

 palladium really was a new metal and 

 Chenivix sent him a small specimen. A 

 few days later another letter J makes the 

 claim that palladium is a platinum-mercury 

 alloy. The editors of the Annales comment 

 upon this that from Vauquelin's experi- 

 ments Chenivix is probably wrong. It is 

 interesting to read the comments of Cheni- 

 vix upon the masking of the individual 

 properties of both platinum and mercury 

 in palladium §, a correct moral drawn from 



*Ann. Chim., 46, 333 (1803). 



i Ann. de Chim. 46, 3Z3 {1803). 



tlbid., p. 336. 



? " The substance which has been treated of in this 

 paper, must convince us how dangerous it is to form 

 a theory before we are provided with a sufBcient 

 number of facts, or to substitute the results of a few 

 observations for the general laws of nature. If a 

 theory is sometimes useful, as a standard to which we 

 may refer our knowledge, it is at other times preju- 

 dicial, by creating an attachment in our minds to 



