June 29, 1900.] 



SCIENCE. 



1015 



man shall meet with small stones of the 

 same stuffe, most of all within the brookes, 

 that be dry sometimes of the yere. This 

 sandie and grauelly substance, the mine 

 masters and mettall finers use to wash, and 

 that which settleth downeward, they burne 

 and melt in the furnace. There is found 

 likewise in the gold mines a kind of led ore 

 which they cal Elutia ; for that the water 

 that they let into these mines (as I said 

 before) washeth and carrieth down withall 

 certain little blacke stones streaked and 

 marked a little with a kind of white, and 

 as heavy they be in hand as the very ore 

 of gold ; and therefore gathered they be 

 with the same ore, and laid in the paniers 

 together therewith ; and afterward in the 

 furnace when the lire hath made a separa- 

 tion between them, and gold, so soone as 

 they are melted do resolue into the sub- 

 stance of the white lead or tin glance 

 aforesaid." 



If Pliny's observation that this variety of 

 plumbum candidum is as heavy as gold could 

 be relied upon, the view would be plausible 

 that he was cognizant of platinum, but un- 

 fortunately in other places he gives evidence 

 of great inaccuracy in this respect. So too 

 there seems no good reason for considering 

 the metallic eledrum to be anything other 

 than the natural or artificial white alloy of 

 gold and silver. If there were any question 

 as to whether platinum were known to the 

 ancients, it would seem to be completely 

 answered in the negative by the fact that 

 no platinum object, no nugget, or grain of 

 platinum has been found among ancient re- 

 mains. 



Soon after the introduction of platinum 

 into Europe, no inconsiderable amount of 

 work was done upon it, by Watson, Scheffer, 

 Lewis, Macquer, Marggraf, Bergman, Guy- 

 ton de Morveau, and others. A few chem- 

 ists, led by Buffon,* cast doubts upon its 

 elementary character. Buffon when read- 



*Obs. sur.phys. (Eozier), 3, 322 (1774). 



ing his history of minerals to the Dijon 

 Academy held that platinum was an alloy 

 of gold and iron, because it was attracted 

 by a magnet, and, said he, if platinum be a 

 metal there must be a second substance in 

 nature attracted by a magnet. Von Milly 

 believed that mercury was also present in 

 the alloy, but Blondeau,* professor of math- 

 ematics at Brest, showed the great improb- 

 ability that platinum was anything other 

 than a simple metal. 



The first suggestion of a practical use for 

 platinum seems to have come from Lavois- 

 ier's t observation of its value for labora- 

 tory utensils. Many efforts were made in 

 the last decade of the eighteenth century 

 to fuse platinum or to get it into workable 

 form. The first recorded success in this 

 direction was that of Janetty,J a Parisian 

 artisan who melted platinum by alloying it 

 with arsenic. It was also alloyed with lead 

 or with bismuth and then cupelled. Be- 

 fore 1800 I'abbe Kochon § wrapped grains 

 of platinum in platinum foil, heated to red- 

 ness and then hammered into an ingot. 

 Moussin-Poushkin || amalgamated platinum 

 sponge with mercury and ignited in a 

 muffle. Another process is descrifced,^ of 

 wrapping ammonium chloroplatinate in 

 platinum foil, igniting, and hammering. 

 In 1800 Knight** published his process 

 which with some modifications was gener- 

 ally adopted and remained in use till the 

 metal was fused in the flame of an oxyhy- 

 drogen blowpipe by Deville and Debray, 

 more than half a century later. Knight's 

 process consisted in heating platinum 

 sponge in a nearly cylindrical but slightly 

 tapering clay mould, and compressing it by 



*/fr(d., 4, 154 (1774). 

 t Annales de chim., 5, 137 (1790). 

 t Chem. Ann. (Crell), 1790, ii, 53. The name is 

 also spelled Jeanty, Jeannety, and Jannety. 

 ?iAnn. der Phys. (Gilbert), 4, 282 (1100). 

 II Chem. Ann. (Crell), 1799, ii, 359. 

 1[PM. 3Iag., 21, 175 (1805). 

 **Ibid., 6, (1800). 



